Mine is a euro 1991 944S2. Most of the time the car would start right the way when the key is turned. By occassionally, the car would have hard time starting. And during these instances, the gas pedal would have no effects (when been stepped on, the gas does not seem to go into the engine). After struggling for a period of about 15 to 30 seconds, the engine would start and run normally. I don't have stalling problem, just hard the get it started sometimes. Does this sound like something is wrong with the air flow meter?

Eric

 

Does it happen when the car is hot? As in shut down 20 minutes before kinda thing.

 

It doesn't happen much in the morning when the engine is cold. But it does happen more often after the car has been driven (yes, when the engine is hot).

 

Does it start if you give it a little throttle pedal? My .02 worth would be on the FPR on the fuel rail-

 

Could be the DME relay:

http://www.clarks-garage.com/shop-manual/fuel-05.htm

You can jumper it and see if the car starts right up. The replacement 993 part is more reliable.

-Joel.

 

Mine did that (especially when warm) until I replaced the fuel pressure regulator, now it starts instantly every time, warm or cold. Check your fuel pressure and fuel pressure leak-down as desccibed in the Factory Service Manual or Clark's.

'88 944S

 

The throttle pedal has no effect when the car wouldn't start no matter how much I step on the pedal. So the air flow meter shouldn't be the cause of this?

 

Replace the DME relay first, and check the connectors for the speed and reference sensors. Both are common causes of hot start trouble and are cheap and easy things to check and replace (DME relay should be replaced anyway if you dont know the age).

The gas pedal wouldnt have an effect. The DME controls the startup fuel, spark, etc. If the relay isnt working correctly (not getting power to the fuel pump right away due to age and stickyness and stuff) then theres little or no fuel pressure and thus hard starting. The two connectors I mentioned are for the flywheel sensors, basically so the DME knows where the engine is at in its cycle, and how fast its spinning. If those connectors are loose, you get no/bad signals to the DME and then hard starts.

Start with those and see what happens. There are other causes, such as the fuel pressure reg, fuel pump, grounds, other wiring, etc. However the two I mentioned are cheap and easy to check, and are common issues. The other possible causes get more expensive to replace on a whim without trying the basics.

 

I had a little of that problem...my intake boot was loose. It finally came all the way off yesterday and shut the car down. After putting it back on and tightening it up, all was well.

 

Brian - that's a 16V engine (one ref/speed sensor, not two separate).

Eric - please check your fuel pressure. It's way better (and more fun) to measure things instead of guessing.

'88 944S