Help - 944 wont start!!

[BIIOAB]

Hi folks
I'm posting on behalf of my mate who has a 1991 944S2 and his computers crashed.

He only uses it at weekends and being busy recently it was idle for about 3 weeks.
He chareged the battery on friday night, and went to use it on saturday - turned and fired as normal then suddenly cut out. Hasnt been able to start it since just turns & turns. I took a plug out and seems to be a decent spark, but i'm a bit limited in how much i can do, especially on Porkers!!
Is there anything 944 peculiar he should be checking now without having to low-loader it to a specialist - any help/hints appreciated thanks

[matsleight]

Has he got a spare DME relay to try swapping out? Otherwise you can probably try the test on here http://frwilk.com/944dme/ to temporarily bridge the connections to see if i is the DME or not? Worht it for a 10 min test before calling out anyone.

[turbobloke]

Also worth removing the fuel pump relay for a wake-up slap.

[sweetea]

Hi,

[1] First, does the car have an alarm/immobiliser system? If it has the Porsche PA1000 or equivalent Hamilton and Palmer system try and reset the alarm system by locating the fused wires in the fuse box (these are loose). Remove both fuses and re-connect. Try starting the car. The alarm/immobiliser system shuts off the fuel until reset if battery has been disconnected (or becomes flat).

[2] As reviously suggested, replace the DME relay (£18.95 from www.promaxmotorsport.com).
The DME relay electrically engages the fuel pump once it receives a signal from the DME computer to do so.

[3] If neither the above help, the flywheel sensors will need to be examined. Car will not start if it does not detect the engine turning. There are 2 of these on the flywheel - one sends the signal to the DME computer (ECU).

[4] Check you have fuel pressure in the common fuel rail. Should be 3.8 bar when idling (hence, will be a little less when turning over) with vacuum line disconnected.

[5] Make sure cold start sensor is operating and AFM (Air Flow Meter] connections are all good. Make sure DME block connector has not become disturbed or water has not got into passenger footwell.

Symptoms sound to me like no fuel is comming through. Hence, [1] & [2] most likely.

Regards,
Andrew
www.promaxmotorsport.com



>> Edited by sweetea on Monday 14th November 09:09

[BIIOAB]

Thanks to all

I'll pass this info on to him and hope it gets him going - if you think of anything else, post it up please....

[chris312]

Many thanks for advice Andrew and others. After eventually getting round to doing the test as advised, it was the DME relay that was faulty. Will now purchase 2No. (one to replace and a spare for the glovebox) as suggested.

Thanks again for the help.

Chris

[leeme3]

'scuse my ignorance but does the 996 have a DME relay (I think my old 3.2 had one) and if so is it worth carrying a spare around?

[dogsharks]

Very relative thread for all 944 owners.

www.network54.com/Forum/426130/message/1128643557

Dogsharks

[kent993]

While my 993 was in for other work yesterday, I asked about DME relays and was interested to hear about the problems that can occur. The DME relays used always to begin their part number with the figures "944", but experience with failures apparently led to a modified version and these (for the oil-cooled cars, anyway) had "993" at the start of the part number. We decided to check what was on my '96 model car: it turned out to be one beginning with a "944" number! Needless to say, I had it changed, though I'm keeping the old one as a fallback spare.

In passing, it was interesting to hear that removal of the DME relay is probably the best immobiliser you can use! It's easy to get at and to take out, and without it the car's going nowhere without being pushed or trailered!

[diver944]

The 993. version can fail as well.

I replaced my 944. one about 6 years ago. It lasted another 5 years and about 60k miles until last year. I imagine the contacts inside just wear out over time