SR71BLACKBIRD

I have had my 95 993 Coupe almost a month now and I have come across this problem twice.

The first time after a 70 mile drive , I turned off the ignition in my garage; it was about 40 deg and raining. I tried to restart it 30 seconds after and only got cranking. I stopped and waited about 20 seconds and tried again and cranking only and then waited about 3 minutes and tried ignition again and finally started.

I didn't think much of it the first time as I thought that I might have flooded the engine until this morning

Today it was about 30 degrees and clear skys. and had not started the car for about 3 days; The car started instantly and I left it idling for about 5 minutes to warm the car up to drive my daughter to school which was only about 4 minutes away.

We got to the school and I stopped and shut off the engine to help my daughter get out (about 30 seconds) and then got back into the car to leave and started the ignition and all I got was cranking. I tried about cranking 2 additional times and again only cranking. I then waited about 2 minutes and tried again and it finally started.

Anyone with this experience; is this a DME about to go or is it only a flooded engine. Thanks for any input

kkim

Check out this DIY to see if you've got the updated relay.

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

Regardless of which relay you have, I'd buy another and keep one as a spare if this doesn't prove to be the problem this time. I think I paid about $20 for my 993# relay.

Good luck!!

Also, do you know if your wiring harness has been replaced?

SR71BLACKBIRD

Thanks Kelly. I will check if I have the updated DME and get a spare anyways. Yes the Porsche Dealer i purchased the care from replaced the wiring harness.


Scott

Steve Weiner-Rennsport Systems

Hi Scott:

Sure sounds like a dying DME relay to me,....

David in LA

You can't "flood the engine" since it's fuel injected.

Steve Weiner-Rennsport Systems

Wellll,......"Au Contraire", my friend,...

You certainly can flood an FI engine. All it takes is a stuck injector or two,......its not common, but it DOES happen.

Lorenfb

"You can't "flood the engine" since it's fuel injected."

Steve is very correct. Additionally, a no-spark/weak spark at the coils can easily
flood the engine. Once an engine becomes flooded, it's not easy to start.

Other possible intermittent starting problems besides the DME relay;

1. water on the distributor caps
2. water in the DME control unit
3. bad spark plugs
4. bad caps & rotors
5. bad gas
6. low fuel pressure (intermittent pump)
7. weak/marginal pickup sensor

SR71BLACKBIRD

Hmm... This is definitely more complicated than I thought. The strange thing is that if I wait about 3 - 4 minutes after my previous cranks it starts. I tried duplicating the problem again but it doesn't fail to restart at all. Thanks guys

I definitely will get a spare DME.

I phoned around in Seattle and the DMEs are all 40.00 + from the dealers and not the 20.00 that alot of board members are talking about. Any suggestions on where to buy them at $20.00

Thanks

Scott

kkim

From Pelican parts....

Fuel Pump/DME Relay, 944 (#2 Position 83-85/1), 944 (1985/2-91), 924S, 968, 911 Carrera 2/4 (1989-94), 911 Turbo (1991-94), 911/911 Turbo (1995-98)
S-615-227-00 $24.70

JasonAndreas

As a test you can bypass the DME relay to see if it is causing your problem. Run a jumper/wire between connectors 3 and 7 in the relay socket (pins 30 and 87B on the relay) and try to start the car. If it starts up no problem with the wire when it wouldn't start with the relay then you know you need a new relay.

Lorenfb

"I phoned around in Seattle and the DMEs are all 40.00 + from the dealers and not the 20.00 that alot of board members are talking about. Any suggestions on where to buy them at $20.00."

Call some of the Rennlist sponsors. They should be able to save you couple of dollars.
That'll probably help out with your financial situation.

SR71BLACKBIRD

"As a test you can bypass the DME relay to see if it is causing your problem. Run a jumper/wire between connectors 3 and 7 in the relay socket (pins 30 and 87B on the relay) and try to start the car. If it starts up no problem with the wire when it wouldn't start with the relay then you know you need a new relay."

-Jason -this is a dumb question but when I run the wire from connectors 3 & 7 (pins 30 & 87B on the Relay) do I still plug the relay in? or just run the wires between the 3&7 - I know this is a retarded question. - Also as a temp measure can one get home this way if necessary if the relay dies.

Thanks everyone, I just ordered a DME Relay from Pelican per Kelly's suggestion 24.00+5.00 shipping = 29.00. I will leave the spare in the glove box just in case the other one finally dies. I always want to get the best price on parts when I buy stuff - I think its OCD behaviour

Scott

kkim

Scott-

Just to be clear... I wan't trying to get you to buy from Pelican, just showing you that the dealers prices are not always the best.

I hope the relay solves your problem. Sure would suck to get stuck... even worse w/ kids in the car.

BTW, did you check the relay you now have in the car? Is it the 944 or 993 #?

SR71BLACKBIRD

Hi Kelly - its okay, your suggestion was a good one as they seem to have reasonable prices and seem to be the lowest on this part. Barrier Porsche in Bellevue, WA wants 42.00 bucks + 8.8% = 45.00 so thats about 5-6 Starbucks Grande Americanos of savings approx 16.00 - ha ha and I don't have to drive there.

I didn't have a chance to look at the Relay but will do so tonight- this should be interesting and I will let you know.

Thanks

Scott

JasonAndreas

No relay needed, just the jumper wire although I don't think it would make any difference. If you are stuck somewhere and need to drive a short distance you should add another wire to connecter 8 to power the O2 sensors?