J Silverman

So I was enjoying a day at the track yesterday and had some problems on the way home. I was cruising along and all of the sudden heard a popping noise that almost sounded like a backfire and the car died. It refused to start. Im going back to pick it up today, but was wondering if anyone has any ideas what I should start checking. Thanks!!

ChrisJ951

No smoke coming from under the hood? Was the car running hot?

special tool

On your 924S?

931guru

Timing belt?

J Silverman

No smoke, the car wasnt running hot. Yes its my 924S. I dont think it was the timing belt because a) it was just replaced earlier this year, and retensioned, both by a shop that knows what they are doing, and b) I would think that if the belt broke I would have heard the valved hitting the pistons. I will check the inspection hols on the distributer to verify though when I pick the car up later today.

special tool

You can tell if the belt went when you crank - you can hear the difference when your engine has no compression in even 1 cylinder from bent valves.

I would have to go for the distributor first also on a 924S.

J Silverman

Yeah, like I said I dont think it was the belt. Are distributers a common failure in these cars?

cjeckert

Coil popped perchance? See if your getting spark first by pulling a plug and grounding it.

J Silverman

So I drove out to pick the car up yesterday. I go to try to start it to back off the trailer and she fires right up. Its probably the cat again. Go figure....

ChrisJ951

take the cat off.

jpk

I'd put my money on the refrence sensor and/or the connection to it.

J Silverman

Ok so I finally got around to cleaning out the cat, and thought that was the problem. I was cruising around today and all of the sudden the car dies again. Same thing as last time, just no popping noise. Im hiping that like last time, once the car cools off it will restart. I was looking at clarks garage, is there a way to test the reference sensor without an oscilloscope?

ptsheridan

Sounds very similar to what was happening to my 924S the last two weekends. At first seemed just random. Turned out to be a loose connection for the DME relay. Maybe see if you can start the car, then jiggle the relay and see if the car shuts off (mine did). Or try a second DME relay.

-p

Calmchaos

My vote is for speed/ref sensors.

J Silverman

The DME relay is jumpered. I can hear the fuel pump come on with the keyCar has had lots of time to cool off now, and still wont start. Guess I better start looking for a tow truck.

Is there a way to test the ref sensors? Or should I just drop the $130 on a pair of new ones?