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KTPhil 
Samba Member
Joined: April 06, 2006
Posts: 34022
Location: Conejo Valley, CA
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 Posted: Thu Dec 07, 2017 9:55 am Post subject: Re: A few days ago I thought I heard slight pinging |
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What breather setup do you have? The earlier 1-cap style, or the later 2-cap style?
The 1-cap style will have less of a problem with a leaky AAR. In that case, it will be like you cracked the throttle open a little, or adjusted the idle too high -- it's just a throttle leak.
But the 2-cap style, which I am less familiar with, works differently and will cause more problems with a leaky AAR. |
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blues90
Samba Member
Joined: March 14, 2009
Posts: 1912
Location: Hollywood ,CA
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| Posted: Thu Dec 07, 2017 12:04 pm Post subject: Re: A few days ago I thought I heard slight pinging |
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| raygreenwood wrote: |
Really....this all goes back to your other threads. And part of this is STILL the same problem. It's not going to go away.
Understand.......You note that your AAR is not closing. |
When I installed the Dist I rebuilt and was setting the timing I had the AAR blocked off then discovered when I pulled the bolt out the AAR to oil bath hose it was closed yet all the while I still had an RPM fluctuation of about 100 RPM . I can't say if when I actually drove it an hour later if it was closed. The thing is the ARR has been closing on and off for a while and it never pinged once.
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| If that is true and you are driving it that way.....your fuel mixture is way the hell rich. The aar bleed air is read by the MPS as throttle open and it enriches. |
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| If you are able to drive with that condition....and get actual pinging......the only way that can happen (if your fuel pressure is normal).....is if the MPS is adjusted seriously LEAN. |
I need to check the fuel pressure again . I did install that new pump and a filter not long ago and it was 30 PSI it may have changed. The odd thing about the ping is I know the AAR has issues and don't check every time I drive if it fully closes to know for certain I have run it and checked it and it should close within a certain amount of time and it does not . So say it's been acting up and part open for a while now this ping just came out of the blue last friday never did this before. I haven't changed anything before this happened . Also this ping does not always happen . within a block same road it would ping then I would let off as soon as I heard it and step on it not flooring it just a bit more gas and got no ping at all , perhaps just letting off the gas then on it again injected enough fuel via the TPS enrichment so it had enough fuel not to ping . Other times I was at a stop and moving along and once it shifted into second I gave it a bit more gas and it pinged . I was not just a slight normal ping , it was quite pronounced so I let off right away.
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| While this may sound like a good trade off at say.....idle.....it can make it seriously lean through the mid range and part throttle. |
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e The amount of air entering through the open AAR increases at a squarfunction as rpm rises. As the MPS reacts to the extra air...which equals lack of vacuum....which equals enrichment.....it is not linear with the increase of air through the AAR. You will have lean spots.
Also the idle increase and not falling back to set idle....is a dead bang giveaway that you have air bypassing and enriching the MPS at just above idle. |
This is the part that is odd . I know when I used to open the throttle and release it dropped right back to set idle it didn't hang for few seconds then drop.
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| While you may very well have ignition and advance issues as well ....you MUST fix the vacuum leaks and FINALLY adjust the MPS.....before you can accurately set timing based on availabe advance curve of the centrifugal......because the vacuum leak and MPS adjustment will not allow you to have a stable and controllable idle. Ray |
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Last night as I posted I pulled the plug on the air temp sensor . What this does is instantly stabilize the idle . It no longer rises and falls the 100 RPM . How ever if I recall it still does not instantly drop back to set idle speed , I was so frustrated by that point I can't recall .
Last edited by blues90 on Thu Dec 07, 2017 2:39 pm; edited 1 time in total |
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blues90
Samba Member
Joined: March 14, 2009
Posts: 1912
Location: Hollywood ,CA
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| Posted: Thu Dec 07, 2017 12:08 pm Post subject: Re: A few days ago I thought I heard slight pinging |
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| KTPhil wrote: |
I am starting to suspect a misadjusted/broken TPS or wires if it only pings when you give it gas... without the extra injections (like an accel pump on a carb) it will be running lean for a few seconds, and the lean mixture may let it ping.
Most of the manuals have an incorrect adjustment procedure. Get it close, and then listen for the 10 or so extra injector squirts (key on, engine off, slowly open the throttle and listen near the injectors). |
No it works , I get all the clicks I just checked it last week before the ping . I wanted t be certain all the contacts worked when the should. I also can hear then just key on pressing the pedal down . |
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blues90
Samba Member
Joined: March 14, 2009
Posts: 1912
Location: Hollywood ,CA
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| Posted: Thu Dec 07, 2017 12:15 pm Post subject: Re: A few days ago I thought I heard slight pinging |
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| KTPhil wrote: |
What breather setup do you have? The earlier 1-cap style, or the later 2-cap style?
The 1-cap style will have less of a problem with a leaky AAR. In that case, it will be like you cracked the throttle open a little, or adjusted the idle too high -- it's just a throttle leak.
But the 2-cap style, which I am less familiar with, works differently and will cause more problems with a leaky AAR. |
Later 2 cap with PCV . Ray brought this up as far as the ARR. What I'm going to do is start it and then plug the ARR and drive just to take it out of the picture.
The real killer here in good ol hollywood is the damn traffic , even if I wanted to get on a freeway chances are I would be in the same stop and go as these over packed insane side and main streets . I'm lucky to hit 45 MPH let alone try to step on the gas to find when the ping might come in or if it happens at all without someone in front of me . |
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blues90
Samba Member
Joined: March 14, 2009
Posts: 1912
Location: Hollywood ,CA
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| Posted: Thu Dec 07, 2017 2:34 pm Post subject: Re: A few days ago I thought I heard slight pinging |
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Today it started right up yet the fuel pressure bleeds down over night so I'm pretty certain I need a FPR.
I had the air temp sensor unplugged and drive it about 1/2 mile no ping , got home letting it run I checked the ARR and is was partly open. Then I drove it one mile round trip no ping and parking it for say 20 minutes drove home and still running it seemed the ARR was closed at least if there was any vacuum I could not feel it so I will try a vacuum gauge. I didn't think to see if the idle dropped back fully letting off the throttle. All this tells me is with the air temp sensor unplugged there is an across the board 10% increase in richness. My understanding has always been any vacuum leak will make it run richer because it screws with the vacuum signature which in turn affects the MPS which is basic. What I don't know is if this is at all RPM ranges or certain RPM's and load . You have idle vacuum which is high , heavy load low and steady speed cruise some point in between.
I tend to think I has a few small vacuum leaks . The reason is the ARR is a main one yet when it does close even with the air temp sensor plugged in sometimes it idles fine , they must be vacuum leaks that are there due to vibration or heat or the erratic miss would always be there. I haven't changed the runner short hoses in 20 years or the vacuum line to the auto trans and the runner to head spacer/gaskets I haven't checked to see it the nuts are tight since I installed them . I did clamp the 4 runner hoses in 2009 when all of this insanity began . I tightened every single FI terminal out of the plastic plugs as well as all the FI grounds . Last I did the grounds and the erratic miss was 90% gone the doing nothing it returned.
With the air temp sensor unplugged the erratic miss was gone and it had better pickup and no matter how hard I pushed it I didn't hear any pinging. Also at times the idle was 850 then 900 in drive, once warmed up it was steady @ 900 RPM.
Now with that temp sensor plugged in idle set at 950 as it has been before the ping and even after if I started it the idle was 950 and within a minute it would rise to 1500 then drop back down yet it had the erratic miss and at each stop the idle would be at 900 to 1000 RPM until fully warmed up then it was steady only i drive with a load at idle . Even though the erratic miss was there driving it you would never know.
I can hear ticking and did snug up the right EMPI header to heat EXchanger yet could feel exhaust leaking there. I need to deal with this . Thought I'd remove the header and wrap some sheet aluminum I have around the exchanger pipe so the header fits tight then clamp it with the crappy VW mesh doughnut deal . I tried to find 1 1/2 " regular clamps and non one stocks them. The exhaust leak allows a popping when I let off the gas after stepping on the gas and letting off . for some reason I did not hear this today. Sure did with the air temp sensor connected. |
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KTPhil
Samba Member
Joined: April 06, 2006
Posts: 34022
Location: Conejo Valley, CA
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| Posted: Thu Dec 07, 2017 5:30 pm Post subject: Re: A few days ago I thought I heard slight pinging |
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Have you checked for leaks at the injector seals? Leaks there can vary with temperature and vibration.
I will repeat that I am not familiar with the later 2-plug breather setup, but it is tied more closely to the FI air system and faults can mess with vacuum which will mess with the FI. Plugging the AAR hose will not address the rest of the system.
Can you post a nice photo of your engine bay? |
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blues90
Samba Member
Joined: March 14, 2009
Posts: 1912
Location: Hollywood ,CA
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| Posted: Thu Dec 07, 2017 6:58 pm Post subject: Re: A few days ago I thought I heard slight pinging |
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| KTPhil wrote: |
Have you checked for leaks at the injector seals? Leaks there can vary with temperature and vibration.
I will repeat that I am not familiar with the later 2-plug breather setup, but it is tied more closely to the FI air system and faults can mess with vacuum which will mess with the FI. Plugging the AAR hose will not address the rest of the system.
Can you post a nice photo of your engine bay? |
I replaced the injector seals in 2009 when this issue first came up. Not the pinging , that is new . The seals didn't change a thing.
I have one photo of the engine bay , not great because it's difficult to get the entire engine view in one photo.
What the late two cap system consists of is under the small cap is a PCV / valve that takes vacuum off the rear of the IAD which is a metal tube fixed to the rear cover plate of the Intake air distributor . what this does is the valve closes off at idle and opens as the throttle is open by intake vacuum . There is one hose to each cylinder head each go to the oil bath air filter. That vacuum draws filtered air from the oil bath into each head through the push rod tubes into the crank case and up into the breather where the large cap is through the PCV into the IAD and the fumes are then burned as they are drawn into each cylinder. It's another basic emissions device added in 72 .
I have often thought of getting a single cap early breather yet on those the oil bath is different because the ARR connects at the neck of the oil bath and from what I can tell have a flapper valve before the ARR hose. Now whether my air cleaner would work since the reason the ARR connects to the top only because you don't want unfiltered air drawn into the ARR or into the crank case.
I would also need to plug the one port on each head and the tube to the back of the IAD or I would have a huge vacuum leak since it's a 12 mm ID pipe . Then there is the older breather with just a road draft tube and a rubber dip valve on the end . I don't think they have any provision for filtering the air before the ARR yet I am not sure, it's been a while since I looked . You cannot get a new PCV mine closes at idle at least seems to . From what I've read there are three small slots that allow some air to flow if the valve is closed so you have some venting yet I've read lots of things .
I've seen a diagram of this on Samba it's in the Haynes type 3 repair book . The Bentley does not show it .
As far as I can tell this PCV system is working as it should , the only control part is the valve itself .
Here's a photo of the 73 IAD you can see the pipe at the rear
This one shows the EGR pipe at the top.
The only difference between to one I have on this car from a 72 is it does not have the EGR pipe at the top . That pipe at the rear connects to the PCV on the breather under the small cap . |
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blues90
Samba Member
Joined: March 14, 2009
Posts: 1912
Location: Hollywood ,CA
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| Posted: Sat Dec 09, 2017 1:24 pm Post subject: Re: A few days ago I thought I heard slight pinging |
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I've driven it twice now since I installed the AH dist I rebuilt . Both times I had the air temp sensor unplugged . Once I swapped the distributors and set the timing I lost a bit of pickup. Then when I unplugged the air temp sensor the pickup was restored .
A while back and for some time all the pinging aside which is gone now.
When I had the sensor plugged in and started it cold idle set at 950 . It would run at 950 then rise to 1500 and stay there for a while only in park . If I drove it a half mile and placed it in park the idle was still above 950.
Point is the AAR when open should not raise the idle , perhaps a bit yet not 550 RPM . All it should do is bypass the throttle and allow extra air so the MPS senses this and adds more fuel plus you have the head temp sensor to richen up for cold running. The MPS has the most control on fuel . The temp sensors are correction .
There is a drastic change across the board with the air temp sensor unplugged not only is the erratic idle miss gone it runs better while driving and it no longer has the 1500 RPM cold idle . I set the idle at 950 it drops for a second when I shift into reverse or drive , once warm the idle is a stable 850 AAR closed.
Based on this and that the air temp sensor if true richens by 10 % across the board unplugged . Am I looking for a vacuum leak? ON this site I read no vacuum leaks allowed all the time. The AAR is a vacuum leak by definition to be specific it bypasses the throttle plate and the MPS senses this and allows more fuel and I'm not forgetting the trigger points and their function.
If I had a vacuum leak via a line connected to the IAD it seems this will affect all cylinders . If the vacuum leak is down stream say the runner boots or intake to head gaskets or injector seals this may only affect 1 and possibly 2 cylinders since 2 get injection at the same time.
Since the unplugged air temp guy affects all cylinders and is a fuel compensation device seen by the ECU as is the MPS and trigger points and HTS would I look for a vacuum leak in a line connected to the IAD ?
I see auto trans lines, AAR to IAD , MPS which I've checked and replaced several times with no change . The IAD back cover which I sealed well with high temp silicone and made certain is was flat and bolts tight. The runner boots even if one leaks it may affect one cylinder and even so allows air into the entire IAD so it could affect all. I can find the runner boots yet not the runner to intake gaskets . They are 20 years old . I'm not sure if the plastic of the intakes after 20 years is a great risk if I remove them and and make new gaskets . The only other option is remove the IAD cutting the runner boots and battle with limited access with the two bolts to case that holds the IAD in place.
Any thought's? |
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KTPhil
Samba Member
Joined: April 06, 2006
Posts: 34022
Location: Conejo Valley, CA
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| Posted: Sat Dec 09, 2017 1:50 pm Post subject: Re: A few days ago I thought I heard slight pinging |
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I'd pull both runners and replace all seals. It's a good idea anyway every few years, and with the seals suspect, let's eliminate those as a possibility.
Seals include the rubber tip seals on each injector, the dual-port bakelite spacers with gasket material on each side, and your stubby runner-to-IAD hoses.
When you take them off, be sure to avoid cracking the bakelite if you don't have spares, and don't lose the little metal sleeves/spacers on the pair of mounting studs at the heads, and don't let them fall into the engine!!
When you put things back, wait to do final tightening of nuts until you have everything on loosely. Then start at the heads, tightening the runners to the heads, then jostle the IAD until all four stubby hoses are straight and square, then finally tighten the IAD to the block. This will relieve any stress on the rubber parts, and make them last longer.
Then we can talk about your breather/PVC situation... |
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blues90
Samba Member
Joined: March 14, 2009
Posts: 1912
Location: Hollywood ,CA
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| Posted: Sat Dec 09, 2017 2:18 pm Post subject: Re: A few days ago I thought I heard slight pinging |
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| KTPhil wrote: |
I'd pull both runners and replace all seals. It's a good idea anyway every few years, and with the seals suspect, let's eliminate those as a possibility.
Seals include the rubber tip seals on each injector, the dual-port bakelite spacers with gasket material on each side, and your stubby runner-to-IAD hoses.
When you take them off, be sure to avoid cracking the bakelite if you don't have spares, and don't lose the little metal sleeves/spacers on the pair of mounting studs at the heads, and don't let them fall into the engine!!
When you put things back, wait to do final tightening of nuts until you have everything on loosely. Then start at the heads, tightening the runners to the heads, then jostle the IAD until all four stubby hoses are straight and square, then finally tighten the IAD to the block. This will relieve any stress on the rubber parts, and make them last longer.
Then we can talk about your breather/PVC situation... |
I've done the runners a few times and have the sleeves . The only thing is the runner to intake gaskets being 20 yeas old is the bakelite , if they are brittle I can't find new ones or even good used ones just in case. |
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raygreenwood
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Joined: November 24, 2008
Posts: 21520
Location: Oklahoma City
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| Posted: Sat Dec 09, 2017 7:26 pm Post subject: Re: A few days ago I thought I heard slight pinging |
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| blues90 wrote: |
| KTPhil wrote: |
I'd pull both runners and replace all seals. It's a good idea anyway every few years, and with the seals suspect, let's eliminate those as a possibility.
Seals include the rubber tip seals on each injector, the dual-port bakelite spacers with gasket material on each side, and your stubby runner-to-IAD hoses.
When you take them off, be sure to avoid cracking the bakelite if you don't have spares, and don't lose the little metal sleeves/spacers on the pair of mounting studs at the heads, and don't let them fall into the engine!!
When you put things back, wait to do final tightening of nuts until you have everything on loosely. Then start at the heads, tightening the runners to the heads, then jostle the IAD until all four stubby hoses are straight and square, then finally tighten the IAD to the block. This will relieve any stress on the rubber parts, and make them last longer.
Then we can talk about your breather/PVC situation... |
I've done the runners a few times and have the sleeves . The only thing is the runner to intake gaskets being 20 yeas old is the bakelite , if they are brittle I can't find new ones or even good used ones just in case. |
The bakelite parts are spacers with a paper gasket cast to each side.
The gaskets only function is to compress about .001" to .003" max....to seal the fine machine kerfs in both the manifold end and the head face.
They are a good design...because if you used a thicker gasket....it can squeeze, pucker, pull oil and vacuum past etc.
So.....you can reproduce the effect of this gasket on your existing phenolic blocks....recycle them.
You will not find a gasket paper thin enough. Bear in mind these are made with standard gasket paper of about .006" to .008" ...but about half of that gasket paper is submerged or involved in the cast block. You would need to get gasket paper about .003" thick because if you glued it on with something like Indian head....it would be thicker than you want.
So take your phenolic blocks and sand on a sheet of 400 grit ...switching directions crequentoy.....on glass until the gasket is gone. Then buy a rubber roller cor print making at hobby lobby.....roll out some high temp RTV on thr sheet of glass.
In about 20 strokes it becomes uniform thickness and almost transparent. Roll it onto the phenolic block. Ro two strokes....roll the roller back on the glass to reload it. Do this about three times. It produces a uniform knap....and thickness of about. 001" to .0015" max.
If you put an X on the phenolic block with a sharpy marker befofe you start you will still be able to see it through the RTV....just barely when you are done. RTV this way sets in less than 10 minutes. Let it dry for several hours then flip over and repeat.
This slightly flushable surface makes a perfect seal just like the original. I have a pictorial how to somewhere on the sight I will dig up in the am. Ray |
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blues90
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Joined: March 14, 2009
Posts: 1912
Location: Hollywood ,CA
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| Posted: Sat Dec 09, 2017 8:59 pm Post subject: Re: A few days ago I thought I heard slight pinging |
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Before I do anything I need to get runner hoses and if I'm going that far I may as well replace the oil cooler seals .
At this point I'm not sure the intake gaskets are an issue . I would say the runner hoses may be and the auto trans vacuum hoses , It's been 20 years the runners have been on there.
I'm still trying to get my head around why the air intake sensor unplugged in an instant stops all the missing issues . Yes it may be a vacuum leak no argument here.
I don't see any possible to spray anything on the intake area to know if the intakes leak . #1 because you cannot get to them with the tin covers in place and # 2 since this is the case all I'd know is maybe the injector seal are an issue and replacing them last time didn't change a thing.
Then the issue of the PCV . I have no idea what the early IAD port is like on early FI T-3 systems . . I know it's below the IAD rather than on top as the 73 is . Also the PCV port is at the rear cover and it's pipe starts out at 11 mm ID then drops to 9 mm ID then inside the cover 7 mm ID . The MPS port is at the top between # 3 & #4 runners and this port has a 7 mm ID hose , it also has a 3 mm ID restriction inserted inside that port and it's quite possible this is there to compensate for what the PCV vacuum affect has on the MPS.
For arguments sake if I were to change the breather to an early type it's possible I may need to remove the restriction in that port and I have no idea because I did not design the system . |
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raygreenwood
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Joined: November 24, 2008
Posts: 21520
Location: Oklahoma City
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| Posted: Sun Dec 10, 2017 10:13 am Post subject: Re: A few days ago I thought I heard slight pinging |
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| blues90 wrote: |
Before I do anything I need to get runner hoses and if I'm going that far I may as well replace the oil cooler seals .
At this point I'm not sure the intake gaskets are an issue . I would say the runner hoses may be and the auto trans vacuum hoses , It's been 20 years the runners have been on there.
I'm still trying to get my head around why the air intake sensor unplugged in an instant stops all the missing issues . Yes it may be a vacuum leak no argument here.
I don't see any possible to spray anything on the intake area to know if the intakes leak . #1 because you cannot get to them with the tin covers in place and # 2 since this is the case all I'd know is maybe the injector seal are an issue and replacing them last time didn't change a thing.
Then the issue of the PCV . I have no idea what the early IAD port is like on early FI T-3 systems . . I know it's below the IAD rather than on top as the 73 is . Also the PCV port is at the rear cover and it's pipe starts out at 11 mm ID then drops to 9 mm ID then inside the cover 7 mm ID . The MPS port is at the top between # 3 & #4 runners and this port has a 7 mm ID hose , it also has a 3 mm ID restriction inserted inside that port and it's quite possible this is there to compensate for what the PCV vacuum affect has on the MPS.
For arguments sake if I were to change the breather to an early type it's possible I may need to remove the restriction in that port and I have no idea because I did not design the system . |
Ok.....and when have gone over this before....injector seals replaced in 2009....even with low miles are shot. They are almost 9 years old now. They get hard as a rock
The PCV valve and the two inlet tubes to the heads....DO NOT REMOVE THEM.
This system is identical to the one on the type 4. It is hands down the best crankcase venting system I have seen. It keeps the case and rocker boxes far cleaner than anuthing else. It pulls clean air through the rocker boxes, tnrough the PR tubes, through the case and through the PCv and into the intake.
Its a little less effective at oil vapor control than the type 4 .....but only because the type 4 has an extra "Z" shaped baffel cast into the case that sheds a lot of oil at higb rpm.
The type 3 should be able to be improved in this repsect if you can push a copper "chore boy" scrubbing pad into the PCV breather box....or even better...of uou can find some of the "coir" material drom an air cleaner. This helps the crankcase vapors fo shed oil droplets just like the material in thd air cleaner.
BUT......I am glad you mentioned PCV. Through all of the discussions on uour engine tuning issues.....I have completely forgotten that the type 3 PCV system is funcyiojally identical to type 4......AND type 4 with D-jet has a KNOWN issue at high miles that can cause a good portion of what you are seeing at idle.
Your idle rises and will not come back down because it....either has a little too much fuel in its basic mix.....which in itself may not raise idle unless it has the air to add with that fuel......but then it gets that air from somewhere.....with me so far?
Or alternatively...it can be running a little bit too lean......meaning too much air in the mix......and suddenly gets a little bump of fuel ....probably from MPS reaction.
The PCV valve can cause this. I have no memory of what the type 3 PCV valve looks like inside....but how this valve works in the type 4 is it pops open at random ....because of a COMBINATION....of case pressure and vacuum. As the spring inside gets weak with age....it can pop open from high vacuum alone.
Worse....at least on the type 4.....with age and vibration.....the little wafer diaphram inside cracks. It still seals partly but gives an odd effect. It sticks open or closed randomly.
The problem with the PCV valve on ANY D-jet system is that it operates independently and randomly.....not conrrolled by the ECU.
It dumps its gas impulse into the plenum......right near the MPS......and the MPS...especially the copper diaphragm type....is sensitive enough to react to that.
What many or us havd found to be a MAJOR benefit to tuning in type 4 with D-jet....is to knock the guts out of the inside of the PCV so its just a through hole. Then install a fixed orifice inside of the hose between the oil breather and plenum. Usually rigjt at,3mm on a 1.7L.....maybe a 2mm or 2.5mm orifice on your 1600. This gives way plenty of PCV case scavenging,effect......but now no longer fluctuates at odd and unplanned times.
Once you do this......you simply readjust your fuel mixture baseline to account for the extra constant air inlet. That is usually a simple adjustment....just a tweak at the center adjusting screw on the MPS and an idle readjustment. Ray |
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blues90
Samba Member
Joined: March 14, 2009
Posts: 1912
Location: Hollywood ,CA
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| Posted: Sun Dec 10, 2017 1:57 pm Post subject: Re: A few days ago I thought I heard slight pinging |
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| raygreenwood wrote: |
| blues90 wrote: |
Before I do anything I need to get runner hoses and if I'm going that far I may as well replace the oil cooler seals .
At this point I'm not sure the intake gaskets are an issue . I would say the runner hoses may be and the auto trans vacuum hoses , It's been 20 years the runners have been on there.
I'm still trying to get my head around why the air intake sensor unplugged in an instant stops all the missing issues . Yes it may be a vacuum leak no argument here.
I don't see any possible to spray anything on the intake area to know if the intakes leak . #1 because you cannot get to them with the tin covers in place and # 2 since this is the case all I'd know is maybe the injector seal are an issue and replacing them last time didn't change a thing.
Then the issue of the PCV . I have no idea what the early IAD port is like on early FI T-3 systems . . I know it's below the IAD rather than on top as the 73 is . Also the PCV port is at the rear cover and it's pipe starts out at 11 mm ID then drops to 9 mm ID then inside the cover 7 mm ID . The MPS port is at the top between # 3 & #4 runners and this port has a 7 mm ID hose , it also has a 3 mm ID restriction inserted inside that port and it's quite possible this is there to compensate for what the PCV vacuum affect has on the MPS.
For arguments sake if I were to change the breather to an early type it's possible I may need to remove the restriction in that port and I have no idea because I did not design the system . |
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| Ok.....and when have gone over this before....injector seals replaced in 2009....even with low miles are shot. They are almost 9 years old now. They get hard as a rock |
Back in 2009 is when all this started and it is the reason I joined Samba. You would have to go back and look at what I was dealing with. Point being , after all the parts I changed the injector seals were the last because I needed to wait form them to arrive . They didn't change a thing. No saying they may be dry yet I've had them in just as long and never found them cracked just compressed. When I was all done it and a hunting issue which it never had before and after a bit that just went away. Back then as well as now the only thing that clears this erratic idle miss is unplugging the air temp sensor. Not long ago I cleaned and tightened all the FI connectors out of the plastic plugs then later did the FI grounds and the grounds seemed to make a huge difference yet it returned to the same thing . I rechecked the grounds and they were still fine and I didn't move wires around that might have fixed it temporarily. In 2009 before I changed the plugs and fuel lines and filter valve adjustment and removed the j pipes put the heat exchangers back and changed vacuum lines it ran fine and I've been over all this many times since and still as soon as I unplug that sensor the idle is steady and the erratic miss is gone. It's not a one cylinder steady miss it's random yet persistent as if it affects all the cylinders yet at different times or two cylinders maybe even one , I can't tell . The damn ping just came out of nowhere and a Dist does not one day work fine then not . Sure it needed lube and shims . I think it was just the fuel was just changed to the summer blend so I added 4 gallons of 89 octane right before I changed out the dist. The old one was not dropping back it the 5 BTDC it hung much higher for 2 minutes the one I rebuilt fixed that down to 2 seconds.
The PCV valve and the two inlet tubes to the heads....DO NOT REMOVE THEM.
This system is identical to the one on the type 4. It is hands down the best crankcase venting system I have seen. It keeps the case and rocker boxes far cleaner than anuthing else. It pulls clean air through the rocker boxes, tnrough the PR tubes, through the case and through the PCv and into the intake.
Its a little less effective at oil vapor control than the type 4 .....but only because the type 4 has an extra "Z" shaped baffel cast into the case that sheds a lot of oil at higb rpm.
The type 3 should be able to be improved in this repsect if you can push a copper "chore boy" scrubbing pad into the PCV breather box....or even better...of uou can find some of the "coir" material drom an air cleaner. This helps the crankcase vapors fo shed oil droplets just like the material in thd air cleaner.
BUT......I am glad you mentioned PCV. Through all of the discussions on uour engine tuning issues.....I have completely forgotten that the type 3 PCV system is funcyiojally identical to type 4......AND type 4 with D-jet has a KNOWN issue at high miles that can cause a good portion of what you are seeing at idle.
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| Your idle rises and will not come back down because it....either has a little too much fuel in its basic mix.....which in itself may not raise idle unless it has the air to add with that fuel......but then it gets that air from somewhere.....with me so far? |
Yes , I'm with you so far.
Or alternatively...it can be running a little bit too lean......meaning too much air in the mix......and suddenly gets a little bump of fuel ....probably from MPS reaction.
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| The PCV valve can cause this. I have no memory of what the type 3 PCV valve looks like inside....but how this valve works in the type 4 is it pops open at random ....because of a COMBINATION....of case pressure and vacuum. As the spring inside gets weak with age....it can pop open from high vacuum alone. |
The type 3 PCV is identical to the type 4 . Remember I found the part number on Rennlist or one of those sites and then checked the number Russ has in a parts sheet linked on Samba.
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Worse....at least on the type 4.....with age and vibration.....the little wafer diaphram inside cracks. It still seals partly but gives an odd effect. It sticks open or closed randomly.
What many or us havd found to be a MAJOR benefit to tuning in type 4The problem with the PCV valve on ANY D-jet system is that it operates independently and randomly.....not conrrolled by the ECU.
It dumps its gas impulse into the plenum......right near the MPS......and the MPS...especially the copper diaphragm type....is sensitive enough to react to that.
with D-jet....is to knock the guts out of the inside of the PCV so its just a through hole. Then install a fixed orifice inside of the hose between the oil breather and plenum. Usually rigjt at,3mm on a 1.7L.....maybe a 2mm or 2.5mm orifice on your 1600. This gives way plenty of PCV case scavenging,effect......but now no longer fluctuates at odd and unplanned times.
Once you do this......you simply readjust your fuel mixture baseline to account for the extra constant air inlet. That is usually a simple adjustment....just a tweak at the center adjusting screw on the MPS and an idle readjustment. Ray |
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I looked at the PCV in my breather and I can see the square disc and it's not cracked . At idle it opens a bit , you would think at idle with high IAD vacuum it would be wide open . As I open the throttle it opens more.
On the IAD on this car as I described above the pipe diameter ID starts out at 10 mm then an inch back it drops to 9 mm where it enters the rear cover plate dead center it's 7 mm ID . The port to the MPS is on top between #3 & #4 runners and even though it has a 7 mm ID nipple inside is a 3 mm restriction . Now if this was done to compensate for the 7 mm ID PCV hole I can't say yet they did this for a reason. On the TYPE3 .Org email site Jim and Dave both described the PVC hole in the rear of the IAD as a pin hole size . My car is a Calif sold car theirs are not so they may or may not have the restriction mine has. I have no idea how the PCV in mine acts driving . I have placed my finger over it as well as pinched of the hose and it didn't affect the idle .
The one and only thing that does is the air temp sensor unplugged. Say it's a 10 % across the board increase in richness , some say it's not . This 10% is what clears up the idle fluctuation as well as instantly stop the erratic miss at idle. I tried to ballast the HTS and it took over 500 ohm so it ran the same as it does with the air temp plugged in yet in either case it did not fix the unsteady idle or the erratic miss.
You may recall in 2009 when I checked every wire from the unplugged ECU to each FI component and for sort to ground and thought the air temp sensor wire had a short and it didn't one wire on that sensor is ground in the ECU .
All I read all the time no vacuum leaks allowed in FI.. OK , the MPS senses any extra air which in turn changes the vacuum signature in the IAD just like the AAR is a vacuum leak the MPS see's and in turn ad's more fuel since the throttle plate is closed this is similar to the idle speed screw allows air to pass around the closed throttle.
AS you said before the AAR open should not raise idle speed , maybe a little yet not the 550 above the 950 set idle I had . All it should do is allow more fuel caused by the added air the MPS see's.
Now back to the air temp sensor. Unplugged it does not ad air just fuel . The result of this is I no longer have the 1500 RPM with the AAR open , I no longer have an idle speed that is unsteady , I no longer have that erratic miss . I unplugged it , set the idle to 950 in park once the AAR closes the idle drops to 850 in drive and rises to 900 in park. I checked to make sure the AAR closes it does it just takes longer than it should.
From all of this it tells me I'm lean if it were a vacuum leak that shouldn't richen it. All it should do is the added air the MPS see's would just ad more fuel not alter the fuel to air mix . Does this sound correct? Now if I adjusted the MPS via the screw that will change the fuel to air ratio just like the air temp sensor does. |
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KTPhil
Samba Member
Joined: April 06, 2006
Posts: 34022
Location: Conejo Valley, CA
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| Posted: Sun Dec 10, 2017 8:11 pm Post subject: Re: A few days ago I thought I heard slight pinging |
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I think it's clear you are lean on one or more cylinders. These engines will "hunt" a little while idling and warm if they are a little lean (and from the factory, they were a little lean for idle emissions testing). That, combined with the improvement when you unplug the temp sensor, confirms it.
So the question is why is it lean? With 9 year old tip seals, this is my guess, and if it's only one or two cylinders, it will make THOSE cylinders run lean (and hunt and maybe ping), while the overall vacuum that the MPS reads isn't all that different, since it's only 1 or 2 cylinders, and a long way from the MPS to boot.
That's why I recommend you R&R the runners and make sure all seals, gaskets, and hoses are 100% leak-free.
The danger here is that if you have one lean cylinder, the car may run well enough, but that one cylinder may fry.
Last edited by KTPhil on Sun Dec 10, 2017 11:52 pm; edited 3 times in total |
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blues90
Samba Member
Joined: March 14, 2009
Posts: 1912
Location: Hollywood ,CA
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| Posted: Sun Dec 10, 2017 10:50 pm Post subject: Re: A few days ago I thought I heard slight pinging |
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| KTPhil wrote: |
I think it's clear you are lean on one or more cylinders. These engines will "hunt" a little who idling and warm if they are a little lean (and from the factory, they were a little lean for idle emissions testing). That. combined with the improvement when you unplug the temp sensor, confirms it.
So the question is why is it lean? With 9 year old tip seals, this is my guess, and if it's only one or two cylinders, it will make THOSE cylinders run lean (and hunt and maybe ping), while the overall vacuum that the MPS reads isn't all that different, since it's only 1 or 2 cylinder, and a long way from the MPS to boot.
That's why I recommend you R&R the runners and make sure allheals, gaskets, and hoses are 100% leak-free.
The danger here is that if you have one lean cylinder, the car may run well enough, but that one cylinder may fry. |
I keep trying to picture in my mind just how certain vacuum leaks will affect what and in what way. This is not to resist or discount what you and others have offered.
Since it's known two cylinders get their shot of fuel at the same time yet each has it's own runner and injector and one seal leaks at the seal or the intake to head gasket on the intake stroke it will draw air and lean out the mix . If the leak is at the runner to IAD hose it shouldn't be quite as lean it seems yet considering RPM this takes place in a second at idle.
I've never run across one or 2 injector seals that looked any different than the rest . If 1 or 2 were lean it's possible, lean creating higher temps might do it.
It certainly would not hurt to check and change once I gather the seals and runner boots . Then once this far I may as well change the cooler seals even though removing the left tin is a bit more work.
I can't include the ping in this , that was something that I feel was the fuel ,
I also do wonder when a sniffer is used and say on my engine which right now does not miss fire it's going to read only what comes out the exhaust . say it's lean , it's not going to point to what cylinder/cylinders they are. If I recall even a dyno reads RPM and exhaust and it is only different from just RPM and exhaust from just a sniffer because it applies load.
I need to decide what to use for the thin intake gasket material . I'm not up for getting a hard rubber roller and high temp silicone. Some use thin paper like yellow pages and others used thin cheerios box yet what temp can these handle .
I've got a bit over 2 k miles on it since this issue started unless I missed it before since I usually don't stand near the rear with it running and that's how I noticed it in 2009 when I did all sorts of work and then it started hunting . When that went away on it's own for some odd reason and it was a while before I noticed the erratic miss . I have no idea how long that was. See the last parts I replaced were the injector seals . I can see those without removing anything . The runner hoses and intakes I know are 20 years old.
Wish I knew of a local place to get the runner boots and injector seals the ones I used to are gone now. Then you get hosed on the shipping. |
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raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21520
Location: Oklahoma City
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| Posted: Sun Dec 10, 2017 10:55 pm Post subject: Re: A few days ago I thought I heard slight pinging |
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| KTPhil wrote: |
I think it's clear you are lean on one or more cylinders. These engines will "hunt" a little who idling and warm if they are a little lean (and from the factory, they were a little lean for idle emissions testing). That. combined with the improvement when you unplug the temp sensor, confirms it.
So the question is why is it lean? With 9 year old tip seals, this is my guess, and if it's only one or two cylinders, it will make THOSE cylinders run lean (and hunt and maybe ping), while the overall vacuum that the MPS reads isn't all that different, since it's only 1 or 2 cylinder, and a long way from the MPS to boot.
That's why I recommend you R&R the runners and make sure allheals, gaskets, and hoses are 100% leak-free.
The danger here is that if you have one lean cylinder, the car may run well enough, but that one cylinder may fry. |
I fully agree and have been stating this. Anything you did or replaced in 2009....makes no difference whatsoever. Its all 8-9 years old now....and even if you parked it in a stkrage unit and it has "0" miles on it....most of the rubber and seal parts are shot or suspect from age alone.
The PCV orifice is NOT 7mm. The hose connection and entry may be 7mm....but the diaphram only lifts a few thousandths of an inch....and tips one edge of the diaphram at a time for a split second or so at a time. While a "pinhole" is an inaccurate description......its functionally accurate. The average opening,size in that split second of oscillation that its open is functionally about 1.0 to 3.0mm......yours may be a little less. I know....because I am not guessing. I have measured it and done the math.
Also....you cannot just look at it and say it looks ok. You need to pull it out...clean it and inspect it with a magnifying glass and bright light. These are 40+ year old disposible wear parts.
At the very least.....to test the effect....you can for a,short period plug the line to tje plenum and leave the case vent open to air and see what difference it makes.
If you had to add 500 ohms to CHT....it proves what ai have been saying for a year now. You either have unresolved vacuum leaks and/or need to FINALLY adjust your MPS.
Ray |
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KTPhil
Samba Member
Joined: April 06, 2006
Posts: 34022
Location: Conejo Valley, CA
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| Posted: Sun Dec 10, 2017 11:55 pm Post subject: Re: A few days ago I thought I heard slight pinging |
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| blues90 wrote: |
| Wish I knew of a local place to get the runner boots and injector seals the ones I used to are gone now. Then you get hosed on the shipping. |
Call and then take a trip to the SF valley to Small Car Parts in Reseda. Mario can order them if he doesn't have them in stock. He's a patient guy and if your are, too, he'll take care of all your needs. |
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raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21520
Location: Oklahoma City
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| Posted: Mon Dec 11, 2017 9:27 am Post subject: Re: A few days ago I thought I heard slight pinging |
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| blues90 wrote: |
So the question is why is it lean? With 9 year old tip seals, this is my guess, and if it's only one or two cylinders, it will make THOSE cylinders run lean (and hunt and maybe ping), while the overall vacuum that the MPS reads isn't all that different, since it's only 1 or 2 cylinder, and a long way from the MPS to boot.
That's why I recommend you R&R the runners and make sure allheals, gaskets, and hoses are 100% leak-free.
I keep trying to picture in my mind just how certain vacuum leaks will affect what and in what way. This is not to resist or discount what you and others have offered.
Since it's known two cylinders get their shot of fuel at the same time yet each has it's own runner and injector and one seal leaks at the seal or the intake to head gasket on the intake stroke it will draw air and lean out the mix . If the leak is at the runner to IAD hose it shouldn't be quite as lean it seems yet considering RPM this takes place in a second at idle.
I've never run across one or 2 injector seals that looked any different than the rest . If 1 or 2 were lean it's possible, lean creating higher temps might do it.
It certainly would not hurt to check and change once I gather the seals and runner boots . Then once this far I may as well change the cooler seals even though removing the left tin is a bit more work.
I can't include the ping in this , that was something that I feel was the fuel ,
I also do wonder when a sniffer is used and say on my engine which right now does not miss fire it's going to read only what comes out the exhaust . say it's lean , it's not going to point to what cylinder/cylinders they are. If I recall even a dyno reads RPM and exhaust and it is only different from just RPM and exhaust from just a sniffer because it applies load.
I need to decide what to use for the thin intake gasket material . I'm not up for getting a hard rubber roller and high temp silicone. Some use thin paper like yellow pages and others used thin cheerios box yet what temp can these handle .
See the last parts I replaced were the injector seals . I can see those without removing anything . The runner hoses and intakes I know are 20 years old.
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Ok.....some items I did not get to:
1. The factory injector tip seals suck. Yes....they are adequate.....and yes 1000 people with a combined 6 million years of type 3'ing will chime in their defense that they never had an issue.....but sorry....there are better seals available. If you can get ACTUAL factory seals....they are very good. But 90% of what has been out there aftermarket for decades is just slices of Viton tube and some of them....many of them....are suspect as to whether they are good viton. In hot weather living and driving hard in the central southwest.....the injector seals where they compressed developed cracks. About 2 years like clockwork on daioy driven vehciles
Bear in mind that this was on a type 4. Our engine compartments are enclosed and NOT ventilated like a bus....so the injector tip seals stay hot.
But the factory seal.....was actually molded and in cross section has a double roll shape to aid steering the shape into a sealing surface as it compresses. The knoy oknes I have found that are actually the right size ID OD and length are Echlin available at NAPA.
I started using CIS injection seals...the green viton variety and they are tighter fittkng, tighter sealing and longer lasting. They still get hard over about 2-3 years, but do not crack and do not leak and usually only have to be replaced if the injector is disturbed or removed.
If you can take two fingers and rotate your injector side to side with relative ease while its installed....when the seals are new.....your seal fit sucks. If you can rotate them after 6 months of driving or more.....they are guaranteed to be leaking.
2. That secind part above about two cylinders getting a shot at the same time and intake and injector seals affecting only that cylinder......NO...NO....NO.....NO!
Understand and start thinking like the SYSTEM. Understand how this system does its fuel load metering.
There is no such thing as a vacuum leak in D-jet....that affects only one cylinder. While yes....its true.....that a snall vacuum leak at just one injector tip could cause a lean spot ONLY at that cylinder......that vacuum leak causes that cylinder to run like crap.
One cylinder running even marginally or occasionally like crap....causes a big lumpy, bumpy oscillation in the vacuum signature. The plenum and runner system while excellent at preventing intake air reversion to the TB....operates by being a damper for the reversion of each cylinder. As the intake valve closes and the air column backs up the runner to the plenum......other intake valves are open or opening and any reversion air gets squeezed toward the path of least resistance.....those open valves.
This creates a UNIFORM oscillation of vacuum signature that the MPS is designed and spring loaded to work around. With a sensitive vacuum gauge and a Go-Pro set to 60 frames per second you can film this.......or with very good eyes and good light......you can watch this
oscillation.
That one cylinder running like crap or oddly....either because of a vacuum leak, poor ignition wire or spark plug....or really poor valve adjustment or compression......causes a "burble" or oscillation in the reversion and vacuum signature.......which causes the MPS to oscillate the fuel enrichment response to ALL of the cylinders at once.
This is what I have been POUNDING on for years.....and not many are getting it.
This is NOT a modern injection system where load is sensed as VOLUME.... by a hot wire or a vane/flap.....and then filtered through digital processing to equally feed a uniform injection pulsewidth.
In modern systems....or more modern systems......the system can run quite well even if one or two cylinders are slightly down in compression or have odd ignition here and there as long,as the cumulative intake volume does not decrease or the actual airflow becomes to variable.
This is why......L-jet seems to run so smooth and normal for a loooong time....with nothing to really do.....until one day it does not start or starts to run really bad.....and the semi-lazy owner then starts to check things out and finds out that a whole lot of things are shot.....ignition parts, compression down, small vacuum leaks, fu regulato4 leaking down, valve adjustments off, carbon build up, exhaust leaks.....seemingly all at the same time......while in reality.....they were slowly degrading over time....until they reached a point that affected the running enough to really disturb the intake volume enough to affect the load sensing of the flap.
Hot wire systems with back up MAP sensors run smoother even longer before crapping out because those two sensing methods are highly divorced/insulated....from the actual ACTION of the vacuum signature.
D-jet is highly sensitive to this. Every part in the system is important.....but the MPS....is the keystone of the system. It is YOUR FUEL MIXTURE AND LOAD SENSOR. Every part in the system has some effect on the MPS and its output....and the MPS output makes GLOBAL decisions on fuel mapping. Ray |
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blues90
Samba Member
Joined: March 14, 2009
Posts: 1912
Location: Hollywood ,CA
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| Posted: Mon Dec 11, 2017 11:36 am Post subject: Re: A few days ago I thought I heard slight pinging |
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Ray I've only seen molded injector tip seals with one exception , the set I got from autozone I have not used since they look like sliced rubber hose. With the molded ones once you remove the injectors the seals tend to stay in the runner not on the injectors. This tells me the seal seals due to it being compressed and when new the plastic tip covers center them on the tip.
Seems many online Vw parts dealers sell the molded ones . Last set I got from bus depot.
I recall at some point you said the plastic covers on the injector tips do nothing other than cause possible rust on the tips . Yet without them since this is the area the seals sit against any tip seal would be a loose fit. The seal may compress and seal . I've just never removed the plastic covers.
I'm well aware that the D jet is nothing like modern FI cars which can compensate and adjust almost every aspect on the engine control. timing ,fuel and on and on. They store info and in a sense adapt to conditions the ECU is nothing like this. |
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