Ben's 95 90 Quattro 20vT

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Re: Ben's 95 90 Quattro 20vT

Postby vt10vt » Fri Nov 09, 2018 11:22 pm

Also, congratulations on getting it going, this is looking awesome!
-Shawn C.
2001 S4 6spd Avant blk/blk - stock daily
2002 01E B6 A4 Built FYF, Built 1.8T, HX35 ~330whp
1989 MC-1 200 Avant- MS1 -Gone but will never forget her lessons
1987 5ktq Sedan - Best $500 beater ever
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Re: Ben's 95 90 Quattro 20vT

Postby ChrisAudi80 » Sat Nov 10, 2018 12:31 am

Great news. Good to see it is sorted now.
96 S6 auto
95 80Q AEB VEMS
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Re: Ben's 95 90 Quattro 20vT

Postby Grillage » Sat Nov 10, 2018 9:25 am

vt10vt wrote:
Grillage wrote: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.


I am also running a Walbro. I had to move the fuel pump signal from EC36-15 to elsewhere - I used EC36-3 and it seemed to solve the problem

It had been behaving this way prior - I wasn't sure if it was "normal" due to being a big ass fuel pump and a FPR that I've never dealt with:
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1995 90 Quattro
1994 Cabriolet - 5 speed

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1993 Audi 90 CS Quattro - 1990 CQ - V8 - 1995.5 Audi S6 - 1993 Audi V8 - 2013 A5 Prestige - 2011 A4 Avant - 1986 Maserati Biturbo Spyder
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Re: Ben's 95 90 Quattro 20vT

Postby vt10vt » Sat Nov 10, 2018 9:56 am

Grillage wrote:
vt10vt wrote:
Grillage wrote: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.


I am also running a Walbro. I had to move the fuel pump signal from EC36-15 to elsewhere - I used EC36-3 and it seemed to solve the problem

It had been behaving this way prior - I wasn't sure if it was "normal" due to being a big ass fuel pump and a FPR that I've never dealt with:

Sounds like a similar issue to what I was running into. If you're using the factory 12v to the fuel pump I'd recommend stepping up the wire gauge as well and I don't know how B4 wiring is, but maybe even a direct 12v from the battery to the relay and then back to the pump. Those 400s draw more amps at idle than an 044 does at 6 bar lol.

Anyway, glad you're making progress, and again, nice work as always!
-Shawn C.
2001 S4 6spd Avant blk/blk - stock daily
2002 01E B6 A4 Built FYF, Built 1.8T, HX35 ~330whp
1989 MC-1 200 Avant- MS1 -Gone but will never forget her lessons
1987 5ktq Sedan - Best $500 beater ever
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Re: Ben's 95 90 Quattro 20vT

Postby Afterthought » Sat Nov 10, 2018 11:30 am

Theres something funny about VEMS and the drivers like P259 .
I’ve had issues with mine as well, not working properly with my cooling fan.


Good to hear you got it running , probably time to get some test drive and seat the rings
****
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1983 UrQuattro - http://theprojectpad.com/viewtopic.php?f=11&t=1819&p=72513#p72513
1983 Ur Quattro Amazon Blue / Zebra MC
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Re: Ben's 95 90 Quattro 20vT

Postby ChrisAudi80 » Sun Nov 11, 2018 11:33 pm

Afterthought wrote:Theres something funny about VEMS and the drivers like P259 .
I’ve had issues with mine as well, not working properly with my cooling fan.


Good to hear you got it running , probably time to get some test drive and seat the rings


You should not use P259 for switching relays. They are sensitive to voltage spikes and backfeed (?).
When I made a dedicated relay for the fuel pump, I changed FP out from 36-15 to 36-9. Injector output seems to work way better.
A coil driver doesn't always work because it is logic level IIRC.
96 S6 auto
95 80Q AEB VEMS
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Re: Ben's 95 90 Quattro 20vT

Postby Grillage » Mon Nov 12, 2018 9:02 am

ChrisAudi80 wrote:You should not use P259 for switching relays. They are sensitive to voltage spikes and backfeed (?).
When I made a dedicated relay for the fuel pump, I changed FP out from 36-15 to 36-9. Injector output seems to work way better.
A coil driver doesn't always work because it is logic level IIRC.


I ended up moving it again after talking with Marc. I had an issue where the fuel pump relay was sticking ON after turning off the car. He mentioned that this was sometimes an issue and that the solution was to move the fuel pump signal to a stepper and invert. So far that has solved the problem


Also, I DROVE THE DAMN CAR yesterday! I had some major brake bleeding problems and it took me a few tries to get it to bleed all the way through. I had some issues but Marc is adjusting my tune and I’ll try again when I’m back in town next week. Either way, it was a really good feeling to get it out on the road. I forgot I had replaced the tie rods and that the car is WAY out of alignment but still felt good. Feels so much better than the V6 for sure - even on super low boost
CURRENT
1995 90 Quattro
1994 Cabriolet - 5 speed

PAST
1993 Audi 90 CS Quattro - 1990 CQ - V8 - 1995.5 Audi S6 - 1993 Audi V8 - 2013 A5 Prestige - 2011 A4 Avant - 1986 Maserati Biturbo Spyder
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Re: Ben's 95 90 Quattro 20vT

Postby Afterthought » Mon Nov 12, 2018 9:40 pm

Makes sense . As Chris was mentioning , some of those drivers are weak or something . For example on mine , the cooling fan is relayed and that is done internally to my engine harness. Vems grounds the relay to turn the fan on.
As a result when I powered up the car , as soon as the relay had power my cooling fan would be on no matter what .
If the battery was connected, fan was on.
I believe this is because some of the drivers in vems (like that P.259 for example) can maybe allow path to ground when they shouldn’t , not sure if that means they need a diode or what . I don’t fully understand it yet .
Anyway don’t mean to hijack your thread but maybe that will shed some light on what’s going on. Either way I’m sure Marc has a handle on it way better than I do.

In regards to the V6, it’s absolute useless :)
I much prefer any I-5 engine , However with the b3 vs b4 90 I think the b4 is a few steps ahead , even smoother driving with that v6, chassis is slightly more rigid feel to is due to the metal behind the rear seat . . . If I even build a 90 again I will likely do what you did , even if that means having to change the engine mounts .
****
Afterthought

1983 UrQuattro - http://theprojectpad.com/viewtopic.php?f=11&t=1819&p=72513#p72513
1983 Ur Quattro Amazon Blue / Zebra MC
GMC 2500HD
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