924S Wont start
 

I was wondering if anyone has any insight or suggestions. I went to go start up my car to make sure everything was in order. Engine cranks, nothing. Tach isnt bouncing at all. This leads me to believe the reference sensors are bad, but they were recently replaced earlier this year. The connectors were all taped up, so I peeld back the tape to make sure everything was connected, and it looks like the PO cut off the harness end of the connector to do something and then attaced spade terminals to plugh the wires in to the sensor. Anyways, its all hooked up correctly as far as I can tell and the terminals are making a good connection. I need to fix this ASAP. My cars new owner is supposed to pick the car up next week, and Id rather not have to tell him that its not running. ANy help would be appreciated!

Have you done the normal checks -- fuel, spark, timing?

Check connections at the distributer cap; remove and replace the wires.

Also check the DME relay; a common issue. Sometimes removing and replacing will get it functioning again.

Does it start if you roll-start it? If so, chech flywheel sensor gap (at least this holds for a 911 engine).
Peter

Take the connector off the DME and test the continuity of the speed and reference sensor from there. The 944 manuals that DR links to in his signature have all the diagrams and pin outs your need. By ohming out from the DME connector, you'll know if the wiring is the issue or not.

I removed the distributeer cap and wire and reinstalled everything. The car was running the other day so I'm convinced fuel and spark are ok. I took the reference sensor connectors out and other than being hacked up they look ok. Fuel pump relay is new but I swapped for my spare and no dice. Still nothing.

How do I check for continuity? I'm not so good with electrical stuff...

LOL

You need a volt meter or DVM (digital volt meter).Does volts, ohms, etc... for continuity.

Hey Jason,

It figures that your car gives up the ghost as soon as you are ready to sell it...

I have a bunch of spare parts for my 924S including a good DME if you need it.

Checking the continuity between the DME and ref sensor would be a good place to start. There are a lot of invisible problems that can develop in 20+ year old wiring.

My multi-meter has become my best friend.... I figured out my throttle position sensor and MAF problem that way.

Next stop would be fuel supply - check pressure. A bad fuel pump or pressure regulator could be the problem.

www.clarks-garage.com

might have some good advice for you.

Hope this helps,
Brad

Let me rephrase.... The car was running the other day so I think that the fueling is ok. Since the tach is not moving when trying to get the car started, that means that the DME isnt getting a signal from the reference sensor which means that it wont send a signal to fire the coil. It could either be because of a bad sensor not sending the signal, or bad wiring causing the signal to not make it to the DME.

So Im assuming to test continuity between the sensor and the DME Im going to pull the plug off the sensor, and check for voltage while cranking the car there. Then check for the same voltage at the DME? I apologize if this is basic stuff, but like I said electrical stuff isnt something Ive ever really had to do before.