[PorscheCollecto]

Hi fellow 944’ers,

I need a “little” help with a friends Porsche 944 from 1985 (late model), which I’m trying help fixing a weird start-up / idle running problem.
The car starts, but will only keep alive if throttle/accelerator is being pushed. And even with that, sometime it dies. And sometimes it can be brough to live before dying by pressing accelerator, but no matter what, if you let go of accelerator it dies for sure.
When pressing the accelerator and getting high rpms, engine sounds healthy. Problems appears below 2.000 rpms.
Important to mention, car has been starting and running fine, but suddenly this problem appeared.

These are the things we have tried until now (not listed in order of trying it):
- Verified all fuel pressures are ok.
- Disassembled and verified the AFM.
- Verified generator at the battery with volt meter.
- Did compression test – all good.
- Dissembled DME to verify if water had gotten into the box or other electrical problem. Did find any obvious culprits.
- Tried the simple test of the FPR of disconnecting one of the fuel injectors. Didn’t seem to be the culprit.
- Tested the CPS – not the problem either.
- Managed to simple test ISV, just by putting 12V on it and ground and listening it moves. (no visual inspection)
- No obvious vacuum leaks, but not gone it through meticulously.

I hope you can help if some good advice or if you tried the similar problem before.
Thanks in advance.

BR
Chris