Miraculix

EDiT: Note the date for this post was 09-18-2003!
More info further into the thread on page 2
Car is still not working...

I have a 1994 year model and it stops from 1 to 6 times per day.
After it stops it takes from 1 up to 10 minutes before the car starts again.

I just picked up the car from Porsche service where they changed the main wiering harness but this didn't do the thing so now I'm a bit confused what to do. It has to be something with the electric fuel system.

The owner before me changed the ECU 2 years ago so it's mighty strange if that new box has mailfunctioning.

I checked the fuel pump relay and replaced it with a new.

Has anyone else had the same problems I'm experiencing or do you have any idea of what to do?

Kind regards

Thomas

graham_mitchell

When you say the car 'stops', what do you mean exactly? Does the engine turn over but not fire up?

Miraculix

Yepp! That's exactly what I mean. Can you imagine standing in the middle of a crossing with a Porsche, the engine is turning over but it wont ignite (or what to say) it's embarassing, haha! And sometimes 6 times 'a day..

Surj-993C2S

DME Relay - get a new one.

Miraculix

Yes, that's what I had in mind next, it's just that I already have the correct one placed in my car. Check the link:

http://p-car.com/diy/relay/

swftiii

Eventhough you may have the right one, the 993... model number ones seem to be able to break and cause problems too. Good luck!

I always carry an extra one with me so if it does the trick, I would pick up a second one for the glove box.

Miraculix

Is there a second DME relay in the glovebox?

SLVR

No, he meant a spare one to keep in the glove box.

swftiii

Micaculix - sorry about the confusion (thanks SLVR) - I always have a spare one with me as the DME can cause all sorts of problems where you could be stranded.

-Skip

Ray Calvo

Another thought is the engine temperature sensor; I know on older 911s (Motronic?) if the sensor detected an overheating condition it would shut the engine off (happened to somebody at one of our track events). A bad/deteriorating sensor might do the same thing.

This is speculation and I don't know if this is still the case on the 993.

Miraculix

Ok! Well if the DME relay doesn't work I wont know what to do so I might aswell suggest that to the Porsche repairmen. I have a time scheduled for Monday.

Tell me another thing guys..
Do you have to be a rennlist member to attach your car underneith your name in the forum. I checked it out and it seems to cost money?

graham_mitchell

The membership does cost a small amount per year, but you will save many times that thanks to the helpfulness of others here and you will be helping to keep Rennlist alive!

As for the avatar, some non-members do have photos but I am not sure whether that is still possible.

Miraculix

Hmm.. The Swedish Porsche repairmen doesn't know what to do with the car. Then what in the hell am I supposed to do?

graham_mitchell

Have you tried a new DME? What else have you tried?

graham_mitchell

This might take a while to track down... Intermittent problems are very frustrating.

But if the engine is not firing you are missing either fuel or ignition.

Have you checked that you are getting ignition when the car won't start? You will need a spare ignition lead and a spare spark plug. Disconnect a spark plug connector from one of the distributors and plug a spare lead with spark plug connected instead. Keep the body of the spark plug in contact with the electrical ground. When the ignition and the starter motor are activated you should see the spark working. NOTE: THIS CAN BE DANGEROUS. TRY AT YOUR OWN RISK. ONLY TRY THIS IF YOU FULLY UNDERSTAND HOW TO HANDLE HIGH VOLTAGES AND KEEP SPARK AWAY FROM ANY SOURCE OF FUEL. Maybe someone else knows a safer way.

If you are getting a spark, then test the fuel pump and regulator.

I'm not an expert. Hopefully someone with greater knowledge and experience will be able to help.