tsmith944

Hey guys, I have just done a HG job on a 944 I purchased without ever starting it up. It was sitting so I wanted to service the belts before I fired it up.

It starts every time but from a cold start, and sometimes while warm, the engine cranks over for 6-10 seconds before reluctantly starting. Once it's running it sounds pretty good except if I rev the engine too fast it sputters and almost stalls, but keeps running.

This seems to me like some kid of a fuel problem but I'm just not sure what I should look into.

Anyone have any suggestions, i tried a search, but didn't find anything like this.

Much appreciated!

75ohm

PeteL had this or a similar issue and found it to be the wiring to the DME temp sensor on the head...

tsmith944

thank you!!! i guess my search terms weren't enough to find that thread. I feel good about it being the temp sensor. I will replace that or check the wires.

mytrplseven

After that, I'd check to see how old is the gas in the tank, replace the fuel filter, see if your injectors are firing (noid light, cheap at the auto parts store).

tsmith944

i replaced the temp sensor but it acts the same. i drained all the gas and replaced it with new gas right after i did the HG. i was thinking about replacing the fuel filter. the car does have 187k or so. when the car starts it runs good at idle so i would assume all injectors are firing.

could it be the FPR? i plugged the vacuum hose and it makes a pop and i feel suction from the tubes.

JimV8

Sounds like fuel pressure. Plugged up filter?

CoreySmith

Always a potential culprit for such behavior. It can cause all sorts of strange starting/idling problems. If you rule out all the other excellent suggestions, this could very well cause your behavior. I screwed around with all sorts of things trying to stabilize my start and idle. DME temp sender, rotor, etc. In the end it was the FPR. Replaced and all is well. Bad news is it will cost you $150 to find out......

gtroth

I'd start by measuring fuel pressure and fuel pressure leakdown.