928 GT R

Crank position sensor?

The XX8 GT had a bad CPS and it would start intermittently as well. In my case is was not temperature sensitive... PITA to replace!

Spun

Not sure. It is running without issue, but it has warmed up again... so really hard to tell until its cold again. Once she is running, nothing I do kills it (aside from intentional kills) when I move wires, etc. Was waiting for the next cold morning to report back, but it looks like those are gone for AZ

Spun

I am really leaning this way on this issue. It may be that once it is cold, there is just enough error that this is the driver and when it is warm, it is not. May have to wait until a cold snap to test the theory...

Randy V

Sounds familiar.

https://rennlist.com/forums/928-foru...ermittent.html

Spun

Randy, once I am running, I am golden. It is only a starting up and running issue. I have chafed everything I can think of plus everything recommended to date down and in some cases on my 3rd replacement just to triple check. The CPS was new with the engine rebuild, but I have had new parts that were bad.... after having 7 of these beauties, I think I have had every issue at least once...

i may take a known good CPS and swap next time or just go put a new one in and see if this ever shows up again. It’s a PITA to change, but so is not running when I want.

928 GT R

Regarding changing the CPS: I put a 1" thick firm foam pad on top of the engine and laid on it while replacing the failed one. Took some patience and clever use of prying devices to get the old one out intact...

For anyone contemplating a manifold or head gasket refresh, consider this a mandatory "while you are in there" replacement item as re-routing the wiring with the manifold on the car is beyond tedious!

Good luck!

khalloudy

Intermittent start on cold days can be due to Temp Sensor II. I faced that issue a long time ago and finally discovered it when checking the resistance on the sensor when in cold weather and it showed an open circuit.