Originally Posted by henreezy

I’ve been having an idling issue with my 85.5 944 and am desperately searching for a solution. The car had been starting strange and making sharp crank sounds before starting after a couple gos, and then surging between 1-3k RPM. Sometimes it’d start fine, sometimes it’d start fine and then develop the same surge while driving. In my latest attempt to fix it, I replaced the ICV and icv hoses, cleaned grounds, and replaced the manifold gaskets. Also did the heater control valve while in there. The PO had the vacuum lines replaced (Lindsey kit). The car after that still started bad at first then would start and die quickly, and then for a few good tries started great and idled perfect 1-1.2k RPM. Few minutes later wouldn’t start or faded.

I plan on replacing the throttle bottle seals and potentially looking into the TPS but need to do more research. If anyone can help me solve this I’d be forever greatful 🙇‍♂️.

best,
Mark Bogle

Originally Posted by henreezi

if the crank position sensor is the same as speed and/or reference sensors, he already replaced them.