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nogoodwithusernames
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Joined: November 10, 2014
Posts: 599
Location: CA, USA
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 Posted: Thu Jan 21, 2016 9:46 am Post subject: Stock '71 FI Help!? |
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Hey so I posted in the FI Help sticky but I don't think anyone has checked it lately so I thought I'd do a new thread to get some extra help.
So anyways, my old engine finally went kaput and I haven't been able to finish my new build yet so I stole the Type1 upright engine from my other car and converted it to type3 as much as I could (Aka type3 except dipstick/oil fill)
It is a stock 1600cc dual port that was running awesome on a center mount carb before I stuck the T3 FI on it and shoved it in the back of the square.
Now though it won't idle without dying after it warms up and throughout RPMs and speed it will surge or buck and it's rather poor on gas... On R in about 160miles  (Mostly hwy BTW)
I've checked for a vacuum leak by placing my hand over the throttle body intake and the engine died so we are good there. Bob had suggested checking fuel pressure and voltage in the other thread, the fuel pressure *should* be good (unless maybe with a lower compression it needs to have more or less fuel??) as I did not adjust it at all when switching everything to this engine. I haven't had a chance to check system voltage yet however.
Any other ideas that I should check into??
_________________
71 Squareback, 1.7l T4 w/ crank trigger fuel and spark
(Conversion thread https://www.thesamba.com/vw/forum/viewtopic.php?t=732508&highlight= or https://shoptalkforums.com/viewtopic.php?f=1&t=151375&sid=f0542d44a322d290c29d6609fac7f215 )
74 914, 2.0L w/ D-Jet
-Derek |
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Tram
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Location: Still Feelin' the Bern- Once you've felt it you can't un- feel it.
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| Posted: Thu Jan 21, 2016 11:14 am Post subject: Re: Stock '71 FI Help!? |
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You most definitely need to check your fuel pressure and voltage before moving on- also your ignition system... distributor advances, timing, spark plugs... for example, if you are using Bosch made in India or Platinum plugs, there will cause all sorts of run- ability issues.
After all this has been checked and verified as correct, the next two suspects would be the throttle switch and/ or its setting, and the MAP for a vacuum leak.
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Немає виправдання для війни! Я з Україною.
| Bryan67 wrote: |
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raygreenwood
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Joined: November 24, 2008
Posts: 21518
Location: Oklahoma City
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| Posted: Thu Jan 21, 2016 11:14 am Post subject: Re: Stock '71 FI Help!? |
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| nogoodwithusernames wrote: |
Hey so I posted in the FI Help sticky but I don't think anyone has checked it lately so I thought I'd do a new thread to get some extra help.
So anyways, my old engine finally went kaput and I haven't been able to finish my new build yet so I stole the Type1 upright engine from my other car and converted it to type3 as much as I could (Aka type3 except dipstick/oil fill)
It is a stock 1600cc dual port that was running awesome on a center mount carb before I stuck the T3 FI on it and shoved it in the back of the square.
Now though it won't idle without dying after it warms up and throughout RPMs and speed it will surge or buck and it's rather poor on gas... On R in about 160miles (Mostly hwy BTW)
I've checked for a vacuum leak by placing my hand over the throttle body intake and the engine died so we are good there. Bob had suggested checking fuel pressure and voltage in the other thread, the fuel pressure *should* be good (unless maybe with a lower compression it needs to have more or less fuel??) as I did not adjust it at all when switching everything to this engine. I haven't had a chance to check system voltage yet however.
Any other ideas that I should check into?? |
You really need to start from scratch and go through the system. you need to pay attention to detail. Some items:
1. With any difference in compression...or timing....or cam profile....valve size...exhaust....etc. etc, etc. etc......any engine will require more or less fuel.
Fuel pressure while being ONE method of adjusting fuel volume...is not the primary fuel mixture adjusting tool on this system. Also you cannot get away with "should" be good on any fuel injection system...much less D-jet. It needs to be correct...and stable...meaning no large fluctuations at idle and no large fluctuations on the gauge when you accelerate. 28 psi +/-1...which means the gauge needle should not swing at any time...more than a total spread of 2 psi.
2. Checking for a vacuum leak on fuel injection is NOT putting your hand over the intake and waiting to see if it stalls. That would only find a GROSS vacuum leak large enough to fly birds through.
This system is sensitive to ANY delicate vacuum leak. "0" vacuum leaks of any kind are allowed.
This means that every hose, every runner seal, the intake gaskets, injector seals, the MPS, the vacuum advance can, the gasketed plate on the back of the intake plenum, the AAR closing all the way, its base gasket to the engine case....everything....must be airtight.
Also...the cam must be stock because the intake valve timing is critical on D-jet.
Ignition timing must be spot on...just like factory ...because the distributor position also changes the injection timing.
Lots of little check details...like resistance of injectors, spray pattern of injectors, resistance of CHT and intake air temp distributor, flow and pressure test the fuel pump, adjustment of TVS, resistance and vacuum check of the MPS.....all of these can cause a no idle situation.
Ray |
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Tram
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Location: Still Feelin' the Bern- Once you've felt it you can't un- feel it.
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| Posted: Thu Jan 21, 2016 11:19 am Post subject: Re: Stock '71 FI Help!? |
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_________________
Немає виправдання для війни! Я з Україною.
| Bryan67 wrote: |
| Just my hands. And a little lube. No tools. |
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Tram
Samba Socialist
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Posts: 22727
Location: Still Feelin' the Bern- Once you've felt it you can't un- feel it.
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| Posted: Thu Jan 21, 2016 11:21 am Post subject: Re: Stock '71 FI Help!? |
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What are you using for intake manifold base gaskets?
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Немає виправдання для війни! Я з Україною.
| Bryan67 wrote: |
| Just my hands. And a little lube. No tools. |
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Rex lucy
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Joined: April 10, 2008
Posts: 497
Location: pleasant plains arkansas
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| Posted: Thu Jan 21, 2016 11:37 am Post subject: Re: Stock '71 FI Help!? |
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| do u have the cylinder head temp plugged up or does that upright engine even have one. |
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nogoodwithusernames
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Joined: November 10, 2014
Posts: 599
Location: CA, USA
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| Posted: Thu Jan 21, 2016 12:18 pm Post subject: Re: Stock '71 FI Help!? |
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| Tram wrote: |
| What are you using for intake manifold base gaskets? |
Using the FI spacer bits with curil-t (edit- not curil-t, Dirko RTV). Also brand new and gapped NGK plugs.
| Rex lucy wrote: |
| do u have the cylinder head temp plugged up or does that upright engine even have one. |
Yes I've got it attached and plugged in. (Cylinder heads the builder used must have been universal as it had the threaded hole for it.)
As far as testing everything I'll get working on that over the weekend. I guess I was hoping it'd be something simple but at least I've got somewhere to start!
I'll report back with:
Fuel Pressure
System Voltage
Component/sensor Resistance (Are the numbers for this in the Bentley or what am I looking for in each one?)
After this if I can get it to hold idle I can better set the timing and idle speed.
**Also based on Ray's post about vacuum, how does one go about testing for such fine details? I've never had the whole "spray carb cleaner on it" thing work with the FI, never noticed even a slight change even though at one point I KNEW I had a vacuum leak.
_________________
71 Squareback, 1.7l T4 w/ crank trigger fuel and spark
(Conversion thread https://www.thesamba.com/vw/forum/viewtopic.php?t=732508&highlight= or https://shoptalkforums.com/viewtopic.php?f=1&t=151375&sid=f0542d44a322d290c29d6609fac7f215 )
74 914, 2.0L w/ D-Jet
-Derek
Last edited by nogoodwithusernames on Thu Jan 21, 2016 2:21 pm; edited 1 time in total |
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KTPhil 
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Posts: 34009
Location: Conejo Valley, CA
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| Posted: Thu Jan 21, 2016 1:54 pm Post subject: Re: Stock '71 FI Help!? |
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Redneck stethoscope can often find vacuum leaks.
(hose stuck in your ear, while you roam the other end over possible leak points). |
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raygreenwood
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Posts: 21518
Location: Oklahoma City
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| Posted: Thu Jan 21, 2016 2:07 pm Post subject: Re: Stock '71 FI Help!? |
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Really....the simplest way to test for vacuum leaks.......it to KNOW you have addressed each connection.
Are all of your vacuum lines and hoses new....or did you just dig this system out of a 40 year old box?
If the hoses themselves are of an unknown age.....and old, crusty and oil...then checking for cracks and leaks along their total length can be a crapshoot.
If they are relatively new, clean and pliable...... then pull each ed of every hose off...snip off a small amount to create a clean sealing surface.....and clamp everything.
The injector seals and grommets. .. just replace them. The runner boots....replace them. While you have the center intake off.....to replace the runner boots....pull the back plate and cut a new gasket from gasket paper and use some Permatex ultra black or gray to put it back togther. Replace the hose that comes from that back plate if it has one. Its to critical to screw with.
While you are at it......put suction on the MPS.....make sure it holds vacuum.
Curil T should not be used on the intake gaskets. Its awesome stuff.....but is designed to be a moving joint. It is far too soft for this high vacuum area between machined surfaces....been there and done that.....it will fail at the phenolic block to head or runner joint. Too much squeezes out....and it oozes over time....so as it spreafs out and oozes.....you will find the joint gettkng loose at the nuts....and the high vacuum can suck "rivers" through the curil T.
Use one of the Permatex ultra series. Ultra black is best...ultra copper is next best. Very thin even film......tighten nuts by finger and 1/2 turn more. Let dry for at least 4 hours. Then tighten the rest of the way.
Ray |
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nogoodwithusernames
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Joined: November 10, 2014
Posts: 599
Location: CA, USA
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| Posted: Thu Jan 21, 2016 2:20 pm Post subject: Re: Stock '71 FI Help!? |
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| raygreenwood wrote: |
Really....the simplest way to test for vacuum leaks.......it to KNOW you have addressed each connection.
Are all of your vacuum lines and hoses new....or did you just dig this system out of a 40 year old box?
If the hoses themselves are of an unknown age.....and old, crusty and oil...then checking for cracks and leaks along their total length can be a crapshoot.
If they are relatively new, clean and pliable...... then pull each ed of every hose off...snip off a small amount to create a clean sealing surface.....and clamp everything.
The injector seals and grommets. .. just replace them. The runner boots....replace them. While you have the center intake off.....to replace the runner boots....pull the back plate and cut a new gasket from gasket paper and use some Permatex ultra black or gray to put it back togther. Replace the hose that comes from that back plate if it has one. Its to critical to screw with.
While you are at it......put suction on the MPS.....make sure it holds vacuum.
Curil T should not be used on the intake gaskets. Its awesome stuff.....but is designed to be a moving joint. It is far too soft for this high vacuum area between machined surfaces....been there and done that.....it will fail at the phenolic block to head or runner joint. Too much squeezes out....and it oozes over time....so as it spreafs out and oozes.....you will find the joint gettkng loose at the nuts....and the high vacuum can suck "rivers" through the curil T.
Use one of the Permatex ultra series. Ultra black is best...ultra copper is next best. Very thin even film......tighten nuts by finger and 1/2 turn more. Let dry for at least 4 hours. Then tighten the rest of the way.
Ray |
Just about everything is new. I've got new hose, not clamped however but I should have enough clamps to do so and I'll do that this weekend as well. Runner boots are some high temp soft silicone pieces I got from a local hose shop and they are definitely sealed, they were a few bucks a piece but work great!
Injector seals are all new as of this summer as well.
Only thing would maybe be the gaskets on the intake which I can cut some new ones for.
I checked the MPS at one point just sucking on a hose attached to it and sticking my tongue to it. I don't have any equipment to test for vacuum, but it did stick to my tongue for about a minute before I decided it was good. (I read about that on here somewhere but don't know how true of a test it actually is...)
Also I take back using curil-t, it was actually Dirko RTV but I had to check the product photos on ACN to refresh my memory 
I recall choosing it based on the box saying it could be used on intakes or something but I'll double check and replace it if I need to with something else.
_________________
71 Squareback, 1.7l T4 w/ crank trigger fuel and spark
(Conversion thread https://www.thesamba.com/vw/forum/viewtopic.php?t=732508&highlight= or https://shoptalkforums.com/viewtopic.php?f=1&t=151375&sid=f0542d44a322d290c29d6609fac7f215 )
74 914, 2.0L w/ D-Jet
-Derek |
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raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21518
Location: Oklahoma City
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| Posted: Thu Jan 21, 2016 4:35 pm Post subject: Re: Stock '71 FI Help!? |
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| nogoodwithusernames wrote: |
| raygreenwood wrote: |
Really....the simplest way to test for vacuum leaks.......it to KNOW you have addressed each connection.
Are all of your vacuum lines and hoses new....or did you just dig this system out of a 40 year old box?
If the hoses themselves are of an unknown age.....and old, crusty and oil...then checking for cracks and leaks along their total length can be a crapshoot.
If they are relatively new, clean and pliable...... then pull each ed of every hose off...snip off a small amount to create a clean sealing surface.....and clamp everything.
The injector seals and grommets. .. just replace them. The runner boots....replace them. While you have the center intake off.....to replace the runner boots....pull the back plate and cut a new gasket from gasket paper and use some Permatex ultra black or gray to put it back togther. Replace the hose that comes from that back plate if it has one. Its to critical to screw with.
While you are at it......put suction on the MPS.....make sure it holds vacuum.
Curil T should not be used on the intake gaskets. Its awesome stuff.....but is designed to be a moving joint. It is far too soft for this high vacuum area between machined surfaces....been there and done that.....it will fail at the phenolic block to head or runner joint. Too much squeezes out....and it oozes over time....so as it spreafs out and oozes.....you will find the joint gettkng loose at the nuts....and the high vacuum can suck "rivers" through the curil T.
Use one of the Permatex ultra series. Ultra black is best...ultra copper is next best. Very thin even film......tighten nuts by finger and 1/2 turn more. Let dry for at least 4 hours. Then tighten the rest of the way.
Ray |
Just about everything is new. I've got new hose, not clamped however but I should have enough clamps to do so and I'll do that this weekend as well. Runner boots are some high temp soft silicone pieces I got from a local hose shop and they are definitely sealed, they were a few bucks a piece but work great!
Injector seals are all new as of this summer as well.
Only thing would maybe be the gaskets on the intake which I can cut some new ones for.
I checked the MPS at one point just sucking on a hose attached to it and sticking my tongue to it. I don't have any equipment to test for vacuum, but it did stick to my tongue for about a minute before I decided it was good. (I read about that on here somewhere but don't know how true of a test it actually is...)
Also I take back using curil-t, it was actually Dirko RTV but I had to check the product photos on ACN to refresh my memory
I recall choosing it based on the box saying it could be used on intakes or something but I'll double check and replace it if I need to with something else. |
So far...so good!
Work through the hoses and fuel pressure and timing. Make sure there are no ignition issues. Lots of potential wire or connector issues to think of after the basic checks are done. Ray |
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nogoodwithusernames
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nogoodwithusernames
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D/A/N
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| Posted: Mon Jan 25, 2016 11:54 am Post subject: Re: Stock '71 FI Help!? |
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| nogoodwithusernames wrote: |
Ok here are the resistances.
CHT sensor about 30 minutes after engine shut-off was 0.5ohms
IAT sensor, same time, was 125ohms
All the injectors were 3ohms (from 2.9-3.1 variance max)
Not sure which connections to check on the MAP since there are four prongs?
Do these sound in spec? I have another CHT I could check if needed. |
Are you sure about the .5Ω? Here's the chart for temp sensor resistances. Temp sensor II is what you want to look at. Half an ohm is a kooky reading....unless you have a DVOM with a scale and were on the wrong one?
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nogoodwithusernames
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KTPhil
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| Posted: Mon Jan 25, 2016 6:13 pm Post subject: Re: Stock '71 FI Help!? |
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90 Ω between two outer terminals
350 Ω between two inner terminals |
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nogoodwithusernames
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nogoodwithusernames
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D/A/N
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| Posted: Fri Jan 29, 2016 2:53 pm Post subject: Re: Stock '71 FI Help!? |
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| nogoodwithusernames wrote: |
| Ok so today I was going to check the voltage of the system while running, and I need to unplug B+ to get a proper reading however if I do that I can't start the car?? Do I need to unplug both wires from the B+ part and connect them together so they bypass the regulator? |
What test are you trying to do? Voltage at idle can be measured at bunch of different points depending on what you're testing along with it....at the battery, coil, generator, etc. I've had to do a bunch of voltage tests but never one where I had to unplug B+ b/c like you said, you're disconnecting the battery from the system and you won't be able to start.
Oh, and the test for overall generator output is here:
http://www.speedyjim.net/htm/gen.htm |
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nogoodwithusernames
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| Posted: Fri Jan 29, 2016 3:34 pm Post subject: Re: Stock '71 FI Help!? |
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| D/A/N wrote: |
| nogoodwithusernames wrote: |
| Ok so today I was going to check the voltage of the system while running, and I need to unplug B+ to get a proper reading however if I do that I can't start the car?? Do I need to unplug both wires from the B+ part and connect them together so they bypass the regulator? |
What test are you trying to do? Voltage at idle can be measured at bunch of different points depending on what you're testing along with it....at the battery, coil, generator, etc. I've had to do a bunch of voltage tests but never one where I had to unplug B+ b/c like you said, you're disconnecting the battery from the system and you won't be able to start.
Oh, and the test for overall generator output is here:
http://www.speedyjim.net/htm/gen.htm |
Well that's how the bentley says to do it. It says to unplug the B+ terminal and connect the multimeter there and then to the ground and then to start the engine and you should have 13.5-14.5v.
_________________
71 Squareback, 1.7l T4 w/ crank trigger fuel and spark
(Conversion thread https://www.thesamba.com/vw/forum/viewtopic.php?t=732508&highlight= or https://shoptalkforums.com/viewtopic.php?f=1&t=151375&sid=f0542d44a322d290c29d6609fac7f215 )
74 914, 2.0L w/ D-Jet
-Derek |
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