cold start, or lack there of

[alpinaclone]

Hi, I just purchased a '91 325is, and it is already giving me problems. When it is warm it starts and runs fine, but when cold, like sitting over night, it cranks and doesn't start. When this happens, it will fire and try, but it just won't start. Sometimes, if I feather the accelerator it will start but only briefly and won't rev. I screwed with it a little about two hours ago and got it running by unpulugging the coolant temp sensor for the ecu, it looks to be a new sensor though. Does anyone know what these should ohm out at at around 40 degrees? When the problem occurs I do have fuel and spark. Sorry for the long post, but I am a little pissed at this thing as I have only had it for 3 days.

Thanks, Matt

[jlevie]

The fist thing to look for, since this problem is only on a cold start, would be intake leaks. A cold engine requires a richer mixture and even a small intake leak will cause problems. Unplugging the DME's temp sensor would help in the presence of an intake leak by causing the DME to think that the engine is extremely cold and thus use an even richer mixture.

[alpinaclone]

thanks, I'm gonna dive a little deeper into it this weekend. I'll let you guys know the prognosis.