Ben's 95 90 Quattro 20vT - now with corn power!

[Grillage]

She lives!


https://youtu.be/Gr3rRuk_Jro

[Afterthought]

Nice that's awesome. You've made quick work of this swap man, it takes me like 2 years to do a swap. I guess all your research ahead of time has paid off.
How is it running so far?

[Grillage]

I’ve been out of town all week so just getting it going right tonight.

I hope to make it move on it’s own this weekend and get the exhaust work done

[Grillage]

Another video. Idle is still a little wonky - I'm losing my secondary trigger a bit so its rougher than it should be:

https://youtu.be/UrlP08Eg7dw

[Afterthought]

Are you planning to use the ISV?
Hard to tell in the video but it looks unplugged . I have mine running good without the ISV in there , I can share some settings if you want .

[Grillage]

Running without it at this stage. Marc is saying to tune it to idle without, then use it to fix the peaks and valleys

I’m close to giving it a bit of a drive

[jbrentd]

Just read through your thread. Nice job on the swap. Such a clean car too!

[Afterthought]

You probably know this , but if you’re running it super rich at first when you first drive around and start tuning , like just at the beginning - I actually fouled my plugs so bad I couldn’t get home at one point . I carry a set with me and a wrench usually just in case .

[ChrisAudi80]

I

VEMS reads a super high IAT so I think I want to replace that sensor. It appears to be soldered into the harness. What does everyone use as a replacement? since I'm VEMS, could I go with a different (cheaper/easier to source) sensor and adjust the temp curve?

You could get a 1.8t IAT sensor. That would require a little machining on the flange on the IM. VEMS has the 1.8t IAT as default. Remember the AAN IAT is PTC.

Just caught up on your build. Very nicely done, sir.

[Grillage]

Hi All,

I've been traveling a whole bunch lately so I have not had much time to work on the car the last few weeks. I was able to fix the secondary trigger error by swapping wires on the sensor

I have it running but rough and it's requiring much too much fuel. Marc and I have been trying to troubleshoot it but so far to no avail

Sounds like its missing but I am confused about how that could be.

So far I have verified:
Compression
1-120
2-127
3-130
4-130
5-135

Timing
Timing light shows the marks dead on with light on Cyl #1

Injectors -
Did a slo-mo video of all injectors with 12v LED's stuck into the plugs. This verfied that they all are firing and in the right order)


Plugs -
Did a slo-mo video of all spark plugs sitting on the coil cover to see their spark and verify firing order (video shows Cyl #1 at right hand side)

I also tested the gap that the spark will travel - All plugs jumped a 30kv gap on my coil tester, so they should all be nice and strong

The issue is that it runs rough and requires more fuel than the 1100 cc injectors should need. Also makes less vacuum
On the big injectors, I am needing 4ms when I should be at like 2.8, I tried the V6 injectors to rule out bad new injectors and need 12ms when I should be at 9

what am I missing?

[Afterthought]

Hi All,

I've been traveling a whole bunch lately so I have not had much time to work on the car the last few weeks. I was able to fix the secondary trigger error by swapping wires on the sensor

I have it running but rough and it's requiring much too much fuel. Marc and I have been trying to troubleshoot it but so far to no avail

Sounds like its missing but I am confused about how that could be.

So far I have verified:
Compression
1-120
2-127
3-130
4-130
5-135

Timing
Timing light shows the marks dead on with light on Cyl #1

Injectors -
Did a slo-mo video of all injectors with 12v LED's stuck into the plugs. This verfied that they all are firing and in the right order)


Plugs -
Did a slo-mo video of all spark plugs sitting on the coil cover to see their spark and verify firing order (video shows Cyl #1 at right hand side)

I also tested the gap that the spark will travel - All plugs jumped a 30kv gap on my coil tester, so they should all be nice and strong

The issue is that it runs rough and requires more fuel than the 1100 cc injectors should need. Also makes less vacuum
On the big injectors, I am needing 4ms when I should be at like 2.8, I tried the V6 injectors to rule out bad new injectors and need 12ms when I should be at 9

what am I missing?

What exactly did you do with the sensors and which flywheel are you running ? I have trigger issue too.

Did you and Marc already do the basic stuff like calibrate 02 sensor , set req_fuel rate in vems ? Which fuel pressure regulator are you running .

[Afterthought]

Wait nevermind I re-read it.
You’re saying you need 4ms req fuel with 1100cc injectors , right?
I couldn’t see in the pictures which fuel pressure regulator you’re running , is it adjustable . And you’ve got an in tank wahlbro pump from Marc ? I’m just wondering if the injectors are seeing the pressure they need .

[lorge1989]

Some wierd vac behavior at the fuel pressure regulator? Do you have a way of putting a gauge inline with the fuel rail to make sure its staying at the right pressure?

[Grillage]

Wait nevermind I re-read it.
You’re saying you need 4ms req fuel with 1100cc injectors , right?
I couldn’t see in the pictures which fuel pressure regulator you’re running , is it adjustable . And you’ve got an in tank wahlbro pump from Marc ? I’m just wondering if the injectors are seeing the pressure they need .

Yes. 4ms with 1100cc

The FPR is adjustable and from Marc - I’m in DC for the week and can’t remember the brand. I have it set for 4 bar. It has a gauge on it and it is keeping consistent

Yes also on the walhbro pump.

[Grillage]

Some wierd vac behavior at the fuel pressure regulator? Do you have a way of putting a gauge inline with the fuel rail to make sure its staying at the right pressure?

Good question. I will put a vacuum gauge in there too

[Afterthought]

I ran a gauge on my FPR and set it to 58psi , when you set that it should be with either the car not running (but fuel pump on) or vacuum disconnected from the regulator while the car idles .
Might be worth it just to double check and follow back the Supply and return lines if you changed anything around there .
I run a dedicated vacuum line right from the Manifold to the FPR.

[Grillage]

Spent some more time today and a bit yesterday.

I bought a new WBO2 hoping that was the issue today - it isn't
Put the big injectors back in, new plugs back in. Exhaust on!

However, it still is wonky - taking too much fuel and the lambda is all over the place



I'm attaching the logfile too here.

Seems like a miss but I can't identify anything. pulling injectors is noticeable on each cylinder.

Can anyone see anything obvious?

[ChrisAudi80]

Spent some more time today and a bit yesterday.

I bought a new WBO2 hoping that was the issue today - it isn't
Put the big injectors back in, new plugs back in. Exhaust on!

However, it still is wonky - taking too much fuel and the lambda is all over the place



I'm attaching the logfile too here.

Seems like a miss but I can't identify anything. pulling injectors is noticeable on each cylinder.

Can anyone see anything obvious?

I looked at your config yesterday.

I have seen those settings before in morris400's config. Highly recommend you set end angle injection to 720. 210 is not going to work. It helped morris.

Also, you say you have 1100cc injectors, but the injector settings are the same as morris for DEKA 630s. It says 280cc in the file.
Please see if you can get the correct settings for this injector.
You could try to set EGO step size to 0, not 1. That turns it off.

Did the wideband ever work correctly, or did it change?

[Afterthought]

I think what hes saying is that It requires that 4 ms req_fuel setting to be close on AFR when it should not need to be set nearly that high. I have mine set at 5.1 Ms for 630 CC injectors. If those are 1100cc I think you're right, the ReqFuel should be like 2.8 or something. The part in VEMS that shows "injector sizing 280cc " is display only but nothing is calculated off of it.
One question is 1100CC seems huge. I mean those should be good for like 800 HP, is it possible that they are oversized for the application?
The other thing you mentioned is that the vacuum is not right, is there any chance of a leak somewhere? Vacuum hose disconnected or something?
The gauge on the far top right "Wb02 status" is jumping around a lot , I can't find out how to display this anywhere in my VEMS or I would use it to compare.

[Grillage]

The current theory is that there is an intermittent miss somewhere that is causing the AFR to go crazy. A puff of air each time there is a miss shows a lean lambda and the massive overfueling (4ms vs 2.8ms) compensates and keeps it running.

The 1100 cc injectors are for the eventual E85 setup that will kick ass!

The only way I can make it run is to increase to 4ms - 2.8 stalls.

I have a couple things coming my way to try and rule out coils and some other stuff

[ChrisAudi80]

OK, that makes sense.

However, I think you could try to turn off end angle injection. Just set it to 720. Try and see happens. Can't hurt.

I looked at the log and config. It's not hitting low PW. You sit on 2.0+ IIRC.
What was the fuel pressure again? 3bar? Strange...

[Grillage]

4 bar

[ChrisAudi80]

4 bar

Maybe if you set it to 3 bar it might help with low load tuning.

[Grillage]

Marc sent me a spare ECU and got things figured out. I think the Fuel Pump channel was doing something wonky, maybe not grounding properly? I think it was struggling to maintain pressure. Whatever, because now it works!

settled it in after this video at 2.6ms and it PURRS

[vt10vt]

I think the Fuel Pump channel was doing something wonky, maybe not grounding properly?

What fuel pump are you running and did you have to re pin the harness with the new ECU? I had issues with the standard issue VEMS fuel pump trigger running my Walbro 400 and had to use an injector driver, but if that's the issue you'd have had to repin the FP relay trigger.