Running out of ideas on this one.

About two weeks ago, after starting every single time it was asked to for about 2 years straight, my S didn't start. Haven't been able to get it to fire up since.

So far, we've checked the following:

Fuel pressure at the rail is good.
DME getting power.
Speed/ref sensor signal is present.
Plugs are sparking.
Injectors getting a firing pulse.
Timing belt is "still there" - meaning we just peered in the inspection hole and confirmed it was still there and wasn't excessively loose when poked with a screwdriver.
Haven't checked compression, but when we pulled a plug out, jammed a rag in the "tunnel" for the plug, and cranked it to check if the plug fired, it blew the rag out.

Kind of at a loss here. Any ideas would be, well, realllllllllyyyyy appreciated.

 

I use a spare spark plug to check for spark. Don't have to take the plug out of the head. You could have just as easily sucked the rag into the engine as blow it out.

What did you use to determine that the injectors are firing? A noid light? They could be getting a very short pulse. There is a ballast for the injectors. Reports have that this can go bad but you still see a pulse at the injectors. Just not enough current to open them. Pull the fuel rail and lay it on some rags. Crank the car and see if the injectors are "passing gas".

If the car sounds funny cranking then do a compression test.

 

Yeah, good point, actually did it that way too to make sure that the actual plugs that were in the engine were firing (as opposed to the spare).

Scope. Pulse looked within spec. Was thinking about checking if they're squirting or not.

It actually sounds like it is just about to start, like maybe one of the cylinders will fire, but not all of them.

 

You haven't pulled the valve cover and check the cam cross over chain and tensioner?

 

The 944S also has an additional module mounted on the left inner fender well behind the headlights that drives the injectors IIRC.

If you have the engine at TDC #1 with the cam cover off the cam lobes should point to 1 and 11 o'clock when viewing from the front, exhaust cam being the one with lobes leaning to 1.

Terry S.

 

Try disconnecting the TPS (throttle position switch) on the bottom of the throttle body. It sounds like what my car was up to. While turning over sounded like it wanted to run, but as soon as you let go of the starter it would die. If it does fire when disconnected it will likely idle a little high, but this is a way to diagnose the prob. Someone (on rennlist) suggested this to me when I was having issues, and sure enough, that was the ticket. Good luck.

 

how come nooone suggests things like dic'ing the tps when my car wouldnt start, i had those same symptoms. blah. just shows you gotta keep reading other peoples posts and youll find what you need! maybe thats my problem.

good luck.