J1720

Would a malfunctioning DME water temperature sensor create a no start condition?

odonnell

It could theoretically. With the car sitting at atmospheric temp, what's the resistance across the 2 pins? That should be all the info you need to see if it gives the dme a real reading during cranking.

J1720

I got to check that . I got a no start condition after replacing the vacuum lines. I have done everything I know and still can't figure it out. I got a feeling it's the DME.

shortyboy

try jiggling the speed reference sensors if you havent already.

J1720

I literally tried everything

raleighBahn

Does the tach bounce when you crank it?

J1720

Yes, I also checked all the sensors with the voltage meter. re-took off the intake checked all vacuum lines. Check spark, the only thing I'm waiting on now is a fuel pressure gauge to check presser. I pulled the fuel bar and tested it, they all fired. Guys, I've been working on 944s for 20 years, I never been this stump before. If it's not fuel pressure then is definitely going to be the Dme I guess.

raleighBahn

If your tach is bouncing then probably not s&r. You could check for 12V on your ignition coil and also the primary/secondary resistance readings.

While waiting on your fuel gauge you could pull your dme sensor and jump 30/87b and you should at least hear your fuel pump running (if not, case closed). There is also the old corner case on clark's about too much pressure on the rail (which causes no start) - you can check by pulling one of the injector wires and see if then it starts. Anyway, couple ideas while you wait on the gauge.

J1720

Thank you so much for your help, i'll check the coil. Already tried pulling one plug.

J1720

I jumped it fuel pump ran.

Sincerely, thanks for everybody's help!

Humboldtgrin

Yea bad fuel pump relay. That's what I said right?? Well I meant too.

J1720

I jumped it, it turn the fuel pump on. It sounds like it wants to start, like a starved for fuel. Even though I'm getting fuel coming out injectors I'm wondering if the pressure is low.

shortyboy

When was the fuel filter last changed?

jerome951

Go back to your last changes. Check to ensure all the vac lines are attached to their proper points, and that they're still attached...

J1720

I remove the intake and checked all lines. I ordered a fuel filter with the pressure gauge I'll change that out.


Keep coming with any suggestions, hopefully overlook something.