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Car not firing... ideas where to look first please!

Will Statt

Well-known member
Joined
28 Aug 2003
Messages
525
Well it did fire up.... I hadn't started it for a about 2 months, but needed to move it out of the shed. I connected the battery and she started first turn of the key no problem. I reversed her out of shed, across the yard, and she just stopped. Turns over no problem, with plenty of speed but no sign of firing up. I swapped over the dme for the unused spare I had, but still the same. Plenty of petrol in her.

Any ideas? :(
 
Similar symptoms to mine which was solved by replacing the DME relay.

It's a common issue - carrying a spare is a good idea and they're not expensive.
 
I know that you say you have changed the DME but I too believe that could be the culprit. I would try another one just to be sure. I had a similar problem to you some years back, swapped the relay for my spare and all was fine. Then I decided to put back the old one to see what might happen and hey presto it worked, it just shows that the relays can be temperamental.

Hope you get it sorted.

ATB :)
 
Windy and Leo..... i've changed the dme if you read my original post. But still no firing. Decgraham... the one i replaced it with was brand new in box, and been carried as a spare since reading of the chance of failure.... is it really likely that the spare would be dud?

What other possibilities are there?

Will :(
 
Hi Will,

Your symptoms are classic DME relay issue. I don't wish to insult you but you are looking at the right relay? If your relay is brand new then logic says it should be ok ..but who knows, you can't always apply logic to a 993, that's why I suggested to try one more, do you have another 993er close by?

I can´t think of anything else, as the car is turning over but not catching fuel looks to be the culprit. The only other thing that I can think of is a problem with the ignition?

Good luck with solving the problem and please come back and let us know what it was when you do :thumb:
 

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If you are sure the relay is good then the next place to look is the fuel pump, but its not an easy diy job as it really helps to get the car up on a ramp/lift.

Crank sensor is also a potential culprit on the ignition side.
 
Could be the engine crank sensor ...... that was the problem I had with similar circumstances.
 
+1 for the crank sensor, if DME relay(s) are all good.
 
Well here we go..... I tried for about 30 mins on saturday to get her to restart.... tried both the original, and the new/unused dme relays ( I def had the right one decgraham as it clearly says 'dme' on them both, and dont' worry, I'm not offended as I'm quite capable of getting something like that wrong! :) ) Anyway... battery is really good, and belts the engine over like mad, but no firing so gave up. (and had to push the weighty beast back into the shed :(

I was thinking this morning though that I don't remember hearing the normal 'buzz' of the fuel pump, so think I'll have another go. So.... reconnect battery, press button of PA1000 and sure enough I do here the fuel pump buzzing... but it doesn't seem to stop like it normally does but I turn the key anyway, and she fires up first turn of the engine! (this is with the original DME) Left her running for 5 mins and no repeat of the stoppage, so now I'm mystified! She's overdue a service and mot, so I better get her booked in, and see if anything can be found as I don't fancy getting stranded anywhere.

Thanks for all the helpful suggestions anyway.... and hopefully the prob won't reoccur!

Will
 
When I had issues with the crank sensor, it was very heat dependent, if thats any help. :thumb:
 
HPNer said:
When I had issues with the crank sensor, it was very heat dependent, if thats any help. :thumb:
Had exactly the same. The car died 200yds from Bolton OPC and would not restart. I enrolled the help of 3 members of staff to push me in. After a couple of hours cooling down it fired up again ran for 15mins and then died.
The crank sensor was replaced and I picked the car up the following day. A new holder was required as the sensor had seized in. The position was set with an oscilloscope as it sits slightly differently with a LWF.
 
Hi

Crank sensors can be very tricky when they start to go. As mentioned above, very heat sensitive, and its not always directly obvious because of heat sink.

Best of luck

Berni
 
I would also keep the fuel pump near the top of the list of potential culprits. They can seize and start moving again temporarily.
 

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