Need help, wierd problem

[bdw73]

Ok, first race of the year this past weekend at IRP, and had a really strange problem all weekend
The car is a 83 Rabbit GTI, I just converted it from ITB to GP, the only change motor wise was the bottom end, made no other changes
Here is what it was doing, ran great before the weekend and in the paddock, good idle, etc, go out on the track, runs great for 3 or 4 laps, than just dies,acts like you hit a rev limiter,keep your foot in it will move but continue to die and lose speed, take your foot off the pedal and it just dies, wont restart, will fire but just dies after it goes to 2 to 3000 rpm
water temp was under 180, oil temp was normal. EGT 1350 to 1400
Toe the car in, and push it under the canopy wait 5 minutes more and the car starts and runs great, the idle some times jumps up 500 to 800 RPM's
This happened all weekend both days, we changed the following to no avail
Control Pressure Regulator
Coil
Wires, plugs
Oxy sensor
Pulled the fuel pump relay and ran a jumper
None of those worked?, anyone have anything similiar? or know a hint or fix?
thanks

[racer14itc]

Originally posted by bdw73:
Ok, first race of the year this past weekend at IRP, and had a really strange problem all weekend
The car is a 83 Rabbit GTI, I just converted it from ITB to GP, the only change motor wise was the bottom end, made no other changes
Here is what it was doing, ran great before the weekend and in the paddock, good idle, etc, go out on the track, runs great for 3 or 4 laps, than just dies,acts like you hit a rev limiter,keep your foot in it will move but continue to die and lose speed, take your foot off the pedal and it just dies, wont restart, will fire but just dies after it goes to 2 to 3000 rpm
water temp was under 180, oil temp was normal. EGT 1350 to 1400
Toe the car in, and push it under the canopy wait 5 minutes more and the car starts and runs great, the idle some times jumps up 500 to 800 RPM's
This happened all weekend both days, we changed the following to no avail
Control Pressure Regulator
Coil
Wires, plugs
Oxy sensor
Pulled the fuel pump relay and ran a jumper
None of those worked?, anyone have anything similiar? or know a hint or fix?
thanks

Been there, done that, got the t-shirt and burnt pistons. From your symptoms, my bet is that you have a dead or dying fuel pump. Has the pump ever been allowed to run dry?

What I think happens is that the pump works OK under full load until it overheats and then loses pressure. I swapped the pump out and problem was solved. However, if it is allowed to run dry, even for just a few moments at a time, it will die again soon!

Welcome to GP!

MC



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Mark Coffin
#14 GP BSI Racing/Action Digital/Airborn Coatings/Krispy Kreme VW Scirocco

[bdw73]

Thanks Mark, that is where I was leaning, just didnt have a spare at the track so couldnt try it.
No, the pump has not been allowed to run dry, at least not since I have had the car, 4 years.
My biggest problem is being able to duplicate the problem, since it seemed to only do it under load, if I test it using the Bentley, will that tell me the pump is going or is bad even not under a load? just curious?
thanks for your help

[racer14itc]

Originally posted by bdw73:
Thanks Mark, that is where I was leaning, just didnt have a spare at the track so couldnt try it.
No, the pump has not been allowed to run dry, at least not since I have had the car, 4 years.
My biggest problem is being able to duplicate the problem, since it seemed to only do it under load, if I test it using the Bentley, will that tell me the pump is going or is bad even not under a load? just curious?
thanks for your help

The problem only showed up under load, after 3 or 4 laps. In the pits, it would show perfect pressure, and fuel delivery. I kept trying other stuff, but eventually figured out it was the pump.

Swap the pump out, and see if the problem goes away. My bet is that it will.

MC



------------------
Mark Coffin
#14 GP BSI Racing/Action Digital/Airborn Coatings/Krispy Kreme VW Scirocco

[Bill Miller]

I agree w/ Mark, I'd bet it's the pump.

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MARRS #25 ITB Rabbit GTI (sold) | MARRS #25 HProd Rabbit
SCCA 279608

[Ryan Williams]

Nope, believe the problem is the "flux capacitor".....