245gti
Adapting Stuff
- Joined
- Nov 12, 2002
- Location
- Calgary, Alberta
Good day all. My wife's 740 has been suffering from this strange issue and the parts cannon hasn't managed to fix it. She came home one day saying the car was shutting off randomly, then would catch and run for a few seconds, then shut off and catch. This was random though. It would run fine for a few minutes, then cut out, catch, rinse, repeat. When it first did it while I was driving I made the determination it was a fuel issue, not spark, because there was never any popping in the exhaust when it cut, even at full throttle. I've had a spark cut issue and it feels and acts much differently.
First things first...fuel pump and relay are operating correctly and this isn't acting like a fuel pump issue where it will falter and hesitate. This is an on-off thing.
Initiate parts cannon. The first thing I did was replace the fuel filter, even though I suspected that would not be the problem. The old filter did have some restriction but there was no change with the new filter. I then noticed the wiring to the crank position sensor was badly deteriorated so I replaced the CPS. No change.
I then, with a little help from my friends, started checking the electronics. We found when it was acting up, we were losing the injector pulse...the injectors would just shut off. We checked continuity to all injectors and all was good. Because the injectors are fired through a grounding circuit we checked and cleaned all the grounding points. No difference.
Continue parts cannon. I thought perhaps the ECU was going bad so purchased 2 more correct ECUs and neither made any difference. I even plugged in a turbo ECU I had laying around and that made no difference either. I then changed the EZK box. No difference. I then bought a new ignition switch and put it in. No difference. I've replaced or bypassed every relay in the system that might have anything to do with fuel delivery. Nothing has made a difference.
I've got two of the smartest guys I know working on this and they are both stumped, as am I.
Just a little background on the car...I brought it in from Japan 7 years ago. At that time it had 24,000 km on it. No, that isn't a misprint. A few months after it arrived the odometer drive gear broke so I replaced the cluster with a junkyard one. I'm guessing it has about 100,000 km on it now.
What have I missed?
First things first...fuel pump and relay are operating correctly and this isn't acting like a fuel pump issue where it will falter and hesitate. This is an on-off thing.
Initiate parts cannon. The first thing I did was replace the fuel filter, even though I suspected that would not be the problem. The old filter did have some restriction but there was no change with the new filter. I then noticed the wiring to the crank position sensor was badly deteriorated so I replaced the CPS. No change.
I then, with a little help from my friends, started checking the electronics. We found when it was acting up, we were losing the injector pulse...the injectors would just shut off. We checked continuity to all injectors and all was good. Because the injectors are fired through a grounding circuit we checked and cleaned all the grounding points. No difference.
Continue parts cannon. I thought perhaps the ECU was going bad so purchased 2 more correct ECUs and neither made any difference. I even plugged in a turbo ECU I had laying around and that made no difference either. I then changed the EZK box. No difference. I then bought a new ignition switch and put it in. No difference. I've replaced or bypassed every relay in the system that might have anything to do with fuel delivery. Nothing has made a difference.
I've got two of the smartest guys I know working on this and they are both stumped, as am I.
Just a little background on the car...I brought it in from Japan 7 years ago. At that time it had 24,000 km on it. No, that isn't a misprint. A few months after it arrived the odometer drive gear broke so I replaced the cluster with a junkyard one. I'm guessing it has about 100,000 km on it now.
What have I missed?