| Author |
Message |
digg75
Samba Member
Joined: April 11, 2017
Posts: 105
Location: Sweden
|
 Posted: Mon Mar 02, 2020 10:11 am Post subject: Re: Air bubbles in the fuel tank |
 |
|
So then I have to look at the ignition and MPS.
Everything that you mentioned Ray has been Done.
Groundconnections om case, injector connections are cleaned and tightened.
Also checked the injectors and ”signal”
When it comes to the distributor. When engine is at TDC, should the rotor be pointing in a specific direction? The marking on the distributor I know. But like ”point towards cyl 4 for exemple?
Starting to think of ”what if’s”
Adjustment om the MPS... |
|
| Back to top |
|
 |
raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21513
Location: Oklahoma City
|
| Posted: Mon Mar 02, 2020 10:31 am Post subject: Re: Air bubbles in the fuel tank |
|
|
| digg75 wrote: |
So then I have to look at the ignition and MPS.
Everything that you mentioned Ray has been Done.
Groundconnections om case, injector connections are cleaned and tightened.
Also checked the injectors and ”signal”
When it comes to the distributor. When engine is at TDC, should the rotor be pointing in a specific direction? The marking on the distributor I know. But like ”point towards cyl 4 for exemple?
Starting to think of ”what if’s”
Adjustment om the MPS... |
I can tell you distributor position on a type 4 but take a look in the Brown Bentley for type 3 postion.
Set the timing exactly like the book. If the outer distributor body is too far out of position either from drive position being off or improper timing method....the injection timing can be slightly out of time.
What is your ambient temperature?
I ask because wometimes when you are borderline on mps adjustment.....and tje outside temp is medium cool....like 45-70° F....disconnecting the intake air temp sensor makes a difference in idle. It also is an indicator that the system main fuel adjustment.....the MPS....is "slightly" off.
If you have not checked items like intake to head manifold gaskets, the connecting hoots from intake runner to center manifold, center manifold back plate gasket and iniector tip seals......small vacuum leaks from these can cause these issues.
If you have not PERSONALLY changed these parts.....chances are high one or more is leaking.
Also make sure the voltage to the EFI system is 12 volts or better.
Only when you are 100% positive that all is correct....will we get into MPS adjustment. Ray |
|
| Back to top |
|
|
Bobnotch
Samba Member
Joined: July 06, 2003
Posts: 22413
Location: Kimball, Mi
|
| Posted: Mon Mar 02, 2020 11:26 am Post subject: Re: Air bubbles in the fuel tank |
|
|
If the engine is at TDC for #1 cylinder, the rotor should be pointing at about 7 o'clock on the distributor.
_________________
Bob 65 Notch S with Sunroof
71 Notch ...aka Krunchy; build pics here;
http://www.thesamba.com/vw/forum/viewtopic.php?t=249390 -been busy working
64 T-34 Ghia...aka Wolfie, under construction... http://www.thesamba.com/vw/forum/viewtopic.php?t=412120
| Tram wrote: |
| "Friends are God's way of apologizing for relatives." |
| Tram wrote: |
| People keep confusing "restored" and "restroyed". |
Last edited by Bobnotch on Tue Mar 03, 2020 12:18 pm; edited 1 time in total |
|
| Back to top |
|
|
KTPhil 
Samba Member
Joined: April 06, 2006
Posts: 34003
Location: Conejo Valley, CA
|
|
| Back to top |
|
|
digg75
Samba Member
Joined: April 11, 2017
Posts: 105
Location: Sweden
|
| Posted: Thu Mar 05, 2020 1:18 am Post subject: Re: Air bubbles in the fuel tank |
|
|
Hi,
The ambient temp is about 18 degrees C (64 F).
I have checked for leaks, nothing.
EFI and injector connectors have signal and the correct voltage.
Rotor points at 7 o`clock at TDC. |
|
| Back to top |
|
|
raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21513
Location: Oklahoma City
|
| Posted: Thu Mar 05, 2020 10:12 am Post subject: Re: Air bubbles in the fuel tank |
|
|
OK...getting into the finer points now.
Lets get a little more descriptive of what is happening when you start up. Also...does the rough running clear up with time...like 5-8 minutes?
What is your idle speed?
Do you have a manual or automatic?
What is the resistance reading if your injection trigger points each side? They should be no more than 1.2 ohms each and be not more than 0.2 ohms difference side to side. If they have a slightly higher resistance...cleaning with circuit cleaner and then dragging a sheet of clean paper through the contacts on each side to polish away tarnish....NO ABRASIVE....is all it usually needs.
If its still off...pull the trigger set out and re-flow the solder joints and 90% of the time it fixes it.
Do these one at a time:
When you start up.....have the air filter boot off and with your fingers make sure the throttle plate is closing all the way. Note if putting your fingers on it changes anything.
On start up ...plug the AAR inlet to see if it changes anything.
Wiggle/twist each component plug while its running just started up to look for differences. This includes the ground points on the case centerline.
Unplug the inlet air temp sensor and see if this changes anything.
How well are your valves adjusted? D-jet valve adjustment must be SPOT ON.
Take a look at this thread....and clean up your distributor. If the mechanical advance springs are sticky, have worn pivots or a sloppy plate (and most do)....it can cause a rough idle.
https://www.thesamba.com/vw/forum/viewtopic.php?t=686352
The problem with D-jet...is that any VERY MINUTE change....causes a minute change to running if even for a split second. This changes the vacuum signature....very minutely....even for a split second....and each of these minute changes is READ by the very sensitive MPS....and reacted to....by changing fuel mixture....which makes a further change to vacuum...which is again reacted to...which makes a further change in vacuum...which is then reacted to.............see the problem?
Very, very small changes make for a "cascade" effect....and idle can be rough or submarine up and down.
Usually the problem is a STACK...of small tolerances that are off or changing rapidly from vibration etc.....and not just one large, easy to see thing.
Ray |
|
| Back to top |
|
|
digg75
Samba Member
Joined: April 11, 2017
Posts: 105
Location: Sweden
|
| Posted: Mon Mar 09, 2020 1:09 am Post subject: Re: Air bubbles in the fuel tank |
|
|
So...I Think someone`s messing with me.
The resistance, injection trigger points, 0,2 and 0,4 ohms (side to side)
Cleaned the original distributor and ripped out the 123 ignition distributor.
Now the original distributor is installed again.
When looking at the throttleswitch I noticed that the bottom fasteningscrew was`nt tightened.
Found a throttleswitch "setup/adjust" guide online and had it "reset" by the book.
Adjusted timing, 0 degrees.
Tried to start it up. Started instantliy and it RAN! Without stalling. I`m in chock!
I had it running on idle for 10 minutes without having to touch the throttle once. At that point I adjusted the idlingscrew and it responded to that, wich it has`nt done before.
The idel, without knowing for sure, sits at about 850 rpm.
I increased the fuelpressure to appr. 32 psi.
It runs ok. It`s a bit uneven sometimes, not sure why.
The valves has not been adjusted by me.
Maby I should adjust them and do a new adjustment of the timing after that.
I´ll try to add a film of Engine runnin so you can hear it "drop". |
|
| Back to top |
|
|
raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21513
Location: Oklahoma City
|
| Posted: Mon Mar 09, 2020 7:35 am Post subject: Re: Air bubbles in the fuel tank |
|
|
| digg75 wrote: |
So...I Think someone`s messing with me.
The resistance, injection trigger points, 0,2 and 0,4 ohms (side to side)
Cleaned the original distributor and ripped out the 123 ignition distributor.
Now the original distributor is installed again.
When looking at the throttleswitch I noticed that the bottom fasteningscrew was`nt tightened.
Found a throttleswitch "setup/adjust" guide online and had it "reset" by the book.
Adjusted timing, 0 degrees.
Tried to start it up. Started instantliy and it RAN! Without stalling. I`m in chock!
I had it running on idle for 10 minutes without having to touch the throttle once. At that point I adjusted the idlingscrew and it responded to that, wich it has`nt done before.
The idel, without knowing for sure, sits at about 850 rpm.
I increased the fuelpressure to appr. 32 psi.
It runs ok. It`s a bit uneven sometimes, not sure why.
The valves has not been adjusted by me.
Maby I should adjust them and do a new adjustment of the timing after that.
I´ll try to add a film of Engine runnin so you can hear it "drop". |
😁
1. The trigger point resistance: be sure what kind of VOM you are using and that it is accurate and set in the correct mode. Make aure you are testing using a small female connector with a short wire pigtail to connect to each pin. Over the years.....I have seen maybe 10-15% of trigger point sets.....actually be below 0.9 ohms.
I have had too many people over the years reading with cheap or supect VOM's or not so good methods. You need to also realize how many connection and insulation "joints" there are between each trigger contact. The solder alone is usually close to 1 0hm.
Your readings are probably off a "scale" level.....but I would bet the "difference" you are seeing of about 0.2 ohms.....is correct.
Bear in mind....having slightly high trigger resistance.....or being "off" by 0.2 ohms or more WILL NOT.....make the triggers fail or prevent the engine from running.
Resistance in the system is.....DELAY. its seen as TIME. With the trigger points it can only shorten the potential "window" of time...within which a pair or injections can be on.
So it can cause some running imbalances ir roughness at certain rpms.....but no wholesale stoppage unless other things are incorrect as well.
2. The throttle valve switch will not prevent the engine from starting or running. However if its grossly mis-adjusted..... it can cause a enough of a stumble off the line or at shift transitions to cause poor runnijg or stalling.....if other items are also poorly adjusted.
Whose adjusting method did you use from which book? Most of them are poorly explained or incorrect.
Study this for a while and tell us which TVS switch you have....how many wires does its plug have?
https://www.thesamba.com/vw/forum/viewtopic.php?t=683230
I have another thread about what and why the books are incorrect for TVS adjustment that I will find and post later.
3. Why did you raise the fuel pressure? Understand that each change of 1 psi .....is an increase or decrease....of 3.57% of your total fuel mixture. Thats a lot.
Plus.....these type of injectors are KNOWN to start to fail to reseat or "seal" at about 35 psi and higher. So depending on the accuracy or innacuracy of your gauge.....you could already be close to the edge. This problem causes rough running and or flooding.
However....if a small increase or decrease to fuel pressure.....causes better running.....it is an INDICATOR....that your primary fuel mixture adjustment is probably incorrect. That adjustment is done with the MPS.
Warning.....quit making multiple changes of parts or adjustments at one time. Ray |
|
| Back to top |
|
|
digg75
Samba Member
Joined: April 11, 2017
Posts: 105
Location: Sweden
|
| Posted: Wed Mar 11, 2020 4:58 am Post subject: Re: Air bubbles in the fuel tank |
|
|
The TVS is a 4 pin.
Used this manual: http://bowlsby.net/914/Classic/zTN_Man13.pdf
(Harold T. Glenn, Type 3/4 FI guide)
Just wanted to see if higher pressure made it run better and it did.
Back at 28 psi now and it runs like crap.
Filmed it running at 32 psi.
https://youtu.be/Qfo6Qwk1ZcE
It drops in rpm every 7-8 seconds, and i hav a tapping/knock sound. Should I relate the tap/knock to the valves? |
|
| Back to top |
|
|
raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21513
Location: Oklahoma City
|
| Posted: Wed Mar 11, 2020 11:06 am Post subject: Re: Air bubbles in the fuel tank |
|
|
I would not say this method of adjustment is "wrong"....but This method...is incomplete or poorly sorted out per each unit type a worst.
It a good manual but virtually everything item, most copy and every illustration...is simply copied and pasted from virtually every other manual. Some from the Probst book and most from the Henry Elfrink manual.
Here is the link I was looking for:
https://www.thesamba.com/vw/forum/viewtopic.php?t=340479
Here is a little more on the adjustment for the four pin TVS. My link was incorrect and I had to look for it.
https://www.thesamba.com/vw/forum/viewtopic.php?t=701340&highlight=early++pin+tvs
| Quote: |
Just wanted to see if higher pressure made it run better and it did.
Back at 28 psi now and it runs like crap. |
Yes....this "TELLS" you something. It is telling you that part (if not all) of your problem is that your overall BASELINE fuel mixture...is too low or lean.
The items or inputs that make up "baseline" fuel mixture are fuel pressure and the MPS main armature setting.
All other inputs are "transient" inputs to enrich or lean out the mixture on demand...either acceleration, deceleration or shift points or change in temperature.
The TS-2 Head temp sensor) only is capable of changing your baseline fuel mixture by about 10-15%. The TS-2 (intake air temp sensor) is only capable to about 5-10%.
The auxiliary air regulator.....AAR..or warm up regulator...effectively your choke...is capable to as much as 20-30%. It does this by creating a controlled vacuum leak...which causes the MPS to read that as an open throttle input....so you get more air and fuel...without opening the throttle.
This action....is why its critical that the AAR is closing 100% during warm up and also why you cannot have ANY vacuum leaks no matter how small. They are seen as throttle movement and fuel is added by the MPS.
| Quote: |
| It drops in rpm every 7-8 seconds, and i have a tapping/knock sound. Should I relate the tap/knock to the valves? |
So listening to your engine...first...make sure your injector plugs are on the correct injectors.
The tapping....actually sounds like an exhaust leak.
It acts...like you have either intermittent wiring faults or vibration related vacuum leaks..small ones. Is your wiring old and cracked in any locations or patched?
Also...while idling like that...wiggle teh three wire plug on the trigger points and wiggle the ground connectors on the case centerline.
Have you had the center intake out to actually check the back late gasket for leaks?
But...this is also not uncommon....with a lean condition in teh baseline fuel mixture and that is also what your experiment with turning fuel pressure up indicates.
What happens is that as the lean condition causes idle to increase....but the throttle is not open....the rise in rpm causes the rising vacuum to tweak the MPS...which gives you a shot of fuel by lengthening pulsewidth. That shot of fuel damps idle....because you are not getting added air so the rpm dips.....mixture leans out and the process starts again.
Also...put a timing light on it and watch what the timing does as the rpm rises. If you see a spike in advance...you may have weak advance springs in the distributor or the idle is too high or a combination of both.
Also...depending on how your particular ECU operates....if your TVS is poorly adjusted and the fork contact is too close or in contact with the "enrichment/on" pole...and the arm contact is not in the "parked/idle" cut off position on the TVS...you could be getting t idle enrichment signals. Check the adjustment as per my links. Ray |
|
| Back to top |
|
|
digg75
Samba Member
Joined: April 11, 2017
Posts: 105
Location: Sweden
|
| Posted: Fri Mar 13, 2020 7:39 am Post subject: Re: Air bubbles in the fuel tank |
|
|
Hi,
The auxiliary air regulator, has no leaks from the airfilter to the MSP, new hoses. If I plug it at the airfilter side it drops in rpm but does`nt stall.
When starting the negine Cold I it drops in rpm after a few minutes, gusee thats the AAR doing its job?
Tested to swap the injector plugs, and it doesnt run "better" slightliy worse of what I can hear. I get more "vibrations" I think.
There are no patchs or cracks anywere, it all looks ok.
I wiggled the Three Points at the case and I Think I could here a change in rpm when dooing so. Pulled it apart and sanded of the Points and pinched the connectors, again.
I have not taken the center intake out to actually check the back late gasket for leaks. However, I have used start-gas/spray to look for leaks there and at all possible connections.
BUT! I Think I can hear a small increase in rpm when spraying directliy on the TVS-shaft (gaswire side) where it goes in to the MPS housing.[/u]
Left to do now, adjusting thee TVS. Using the right guide and way 
I`ve set the valves. 2, 3 ,4 was a bit "off".
I adjusted the distributor after that, using a testlamp.
Sat at 0 degrees.
Filmed the Engine running once more after theese adjustments.
https://youtu.be/HLcdUWTHSbo
Important to know! In the film...After the last Changes it runs with the fuelpressure sat at 28 PSI, not 32. And I Think it runs ok actually
[/u] |
|
| Back to top |
|
|
raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21513
Location: Oklahoma City
|
| Posted: Fri Mar 13, 2020 11:14 am Post subject: Re: Air bubbles in the fuel tank |
|
|
| digg75 wrote: |
Hi,
The auxiliary air regulator, has no leaks from the airfilter to the MSP, new hoses. If I plug it at the airfilter side it drops in rpm but does`nt stall.
When starting the negine Cold I it drops in rpm after a few minutes, gusee thats the AAR doing its job?
Tested to swap the injector plugs, and it doesnt run "better" slightliy worse of what I can hear. I get more "vibrations" I think.
There are no patchs or cracks anywere, it all looks ok.
I wiggled the Three Points at the case and I Think I could here a change in rpm when dooing so. Pulled it apart and sanded of the Points and pinched the connectors, again.
I have not taken the center intake out to actually check the back late gasket for leaks. However, I have used start-gas/spray to look for leaks there and at all possible connections.
BUT! I Think I can hear a small increase in rpm when spraying directliy on the TVS-shaft (gaswire side) where it goes in to the MPS housing.[/u]
Left to do now, adjusting thee TVS. Using the right guide and way
I`ve set the valves. 2, 3 ,4 was a bit "off".
I adjusted the distributor after that, using a testlamp.
Sat at 0 degrees.
Filmed the Engine running once more after theese adjustments.
https://youtu.be/HLcdUWTHSbo
Important to know! In the film...After the last Changes it runs with the fuelpressure sat at 28 PSI, not 32. And I Think it runs ok actually
[/u] |
Ok...with regard to the AAR....you may be misunderstanding exactly what we mean by "leaks"
Yes...the hoses that connect it...cannot leak.
BUT...once the engine is fully warmed up...pull off the hose between teh AAR and the air cleaner. Put your thumb over it.
If you feel ANY vacuum at all...or if the idle changes...your AAR is LEAKING About 90% of them do. It is supposed to seal up 100% closed when fully warmed up. With age, most of them have weak bi-metallic springs and do not close all the way.
This excess air....UNLIKE...with a carburetor ...causes enrichment in a D-jet system.
You may have some throttle shaft leaking. Ray |
|
| Back to top |
|
|
digg75
Samba Member
Joined: April 11, 2017
Posts: 105
Location: Sweden
|
| Posted: Sat Mar 14, 2020 7:06 am Post subject: Re: Air bubbles in the fuel tank |
|
|
Hi Ray,
Jupp, I´ve got vakuum from the AAR. It sucks pretty good.
Is there any idea to try adjusting it? |
|
| Back to top |
|
|
raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21513
Location: Oklahoma City
|
| Posted: Sun Mar 15, 2020 7:10 pm Post subject: Re: Air bubbles in the fuel tank |
|
|
The question is ...which kind do you have?
Is it bolted to the engine to the left of the distributor...looks like a small fire hydrant with two slotted screws on top? Thats the engine heat operated version.
Unbolt it from the engine and pull it out. On the bottom is a bi-metallic coils spring. It has a set screw to turn the spring and its marked - or +.
But before you adjust it...clean it very well. It could just be gummed up.
Also at this age...typically the bi-metallic action is weak. Yes...you can adjust it...but it means it throws the scale off. Means it may close a bit early.
The other type is a small pot shaped item with a single red wire going to it. That has electrical heat and the same spring adjustment on the inside...but getting inside is a lot of work....and then putting it back together is even more...and usually the heater coil is burned out. Tell us what you have first...and we can go from there.
Ray |
|
| Back to top |
|
|
digg75
Samba Member
Joined: April 11, 2017
Posts: 105
Location: Sweden
|
| Posted: Mon Mar 16, 2020 12:36 am Post subject: Re: Air bubbles in the fuel tank |
|
|
I’ve got the ”fire hydrant” type.
Had it out and cleaned it a couple of weeks ago.
Cleaned it with brakleen and massaged it to make sure it could move.
But, I can not rely on that it has’nt been tampered with before.
When the engine is varm and having it running, it runs ok but picks up in rpm alot for 20-30 second every 2-3 minutes.
BTW...the valve/sensor "cutoff valve"? that`s mounted underneath the MPS has a electrical and hose Connection.
The hose Connection is broken and unconnected. The coldstart devices has been removed by prev. owner.
I guess it has to be plugged. Would the fact that it`s "open" be a part of the problem?
|
|
| Back to top |
|
|
raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21513
Location: Oklahoma City
|
| Posted: Tue Mar 17, 2020 11:35 am Post subject: Re: Air bubbles in the fuel tank |
|
|
I cant tell what that part is.....but....do you have an automatic transmission? Of so...it may be a deceleration valve. Thats an electrical air valve that is triggered by a combination or an electrical vacuum switch and gear position switch crom transmission. On rpm over run on deceleration...ot bleeds air into the manifold to prevent rich mixture from popping in the exhaust.....that's the theory......but in reality on D-jet that hae fuel cut off at the TPS....ot bleeds air in to prevent overly lean condition when the throttle is kust cracked open but,still in basic over run mode.
Yes....if the vacuum part is poorly adjusted....it can leak vacuum at idle. Ray |
|
| Back to top |
|
|
digg75
Samba Member
Joined: April 11, 2017
Posts: 105
Location: Sweden
|
| Posted: Tue Mar 17, 2020 12:05 pm Post subject: Re: Air bubbles in the fuel tank |
|
|
Hi
Sorry, Its a manual.
Found the part in a picture, no.104 (cold start valve)
I took it out and sealed the hose connection.
|
|
| Back to top |
|
|
digg75
Samba Member
Joined: April 11, 2017
Posts: 105
Location: Sweden
|
| Posted: Tue Mar 02, 2021 6:33 am Post subject: Re: Air bubbles in the fuel tank |
|
|
Gahhhh!!
Still not getting this one idle properly.
Starts up but wants to stall, after a while and acouple of startups it runs but not smooth at all.
When giving throttle it chokes a bit but after a while it revs ok.
I have no vac.leaks.
Valvs adjusted.
Timing adjusted.
Fuel pr. 28.
New plugs.
Acts weird.
https://www.youtube.com/watch?v=8aYsKLdJ9eI
The clip below,
Just started it (cold)
Revs up after appr. 15 sec.
Listen at appr. 2.00 mins when touching the throttle the first time since start.
https://www.youtube.com/watch?v=nnASTkmCzs8[/youtube] |
|
| Back to top |
|
|
|
