Porsche Enthusiasts Club Forum

Hey all, just joined up but been a longtime reader of this forum, great information but i'm not much of a poster....

Thought i'd let you know of a recent problem, my 944 turbo had a non-firing issue, replaced the DME relay with a new non genuine unit, still no good so I feared the worst - wiring or DME issue. Had an auto electrician out today, turns out the original relay failed and the replacement was no good either! He re-soldered the original and its running

Moral of the story, spend another tenner and go genuine!

I have been saying this for years and people have always said to me 'I'll keep the change in my pocket thanks ; you can waste your money'.

I will not even go into full detail of the various sensors I have had go wrong on me that were pattern or 'OE', including hubs with ABS sensors built in (I could not reuse my old sensor since it would have voided the warranty of the hub.; that was such a waste of time in so many ways; 2 weeks for a return anyone as it got sent for 'testing'?), dodgy temperature sensors in the Stag (it claimed it was always running close to too hot when it was not ; I must have through away £30 on sensors after returning loads and finally using a NOS item off a friend), iffy fan rad switches and so on.

You pay your money and take your choice IMHO. That is not to say that the priciest thing will be the best thing either.

It seems I spoke to soon...

The issue is back again, tried my new relay, no good. I've tested both relays as per this guide http://www.clarks-garage.com/shop-manual/fuel-05.htm and both are working as they should.

I can get the car started by jumping pins 30, 87 and 87b on the relay socket and it runs fine but otherwise the fuel pump isn't powering on when the engine's turned over.

Moving forward to this section http://www.clarks-garage.com/shop-manual/fuel-16.htm I have 12V at pins 18 and 35 on the DME harness plug.

I'm thinking its got to be either the Toad immobilisor/alarm or possibly the DME itself?

I had a similar non starting / rough running issue on my 2.7.

Unplugged the temp sensor under the air intake and re attached it . The car started fine but would then start running rough again after a while , cue pull over and repeat process.
Got a new bosch sensor fitted it and now all is well

Thanks i'll try the temp sensor next.

I tested the reference sensors earlier using the ohmeter on my tester, which I think checked out ok:
pins 8 + 27 = 1020 Ohms
25 + 26 = 1012 Ohms
When cranking, 8+27 showed 12 v AC, 25+26 showed 0v.

Reconnected the DME and it fired up! Quick test drive, turned off and then tried starting again - and we're back to the original fault. Will look at removing the sensors and see what state they're in.