engine trouble

[danmason]

I was just about to arrive home today when, changing up into 3rd gear, my engine suddenly lost acceleration and stuttered. So I changed down to 2nd and it stuttered quite badly again around 3000. My first thought was petrol but wasn't actually sure my car would make it back down the road to the garage so drove slowly home.

Well, it shouldn't be fuel - there should be a good 30-odd miles left in the tank. Having stopped the vehicle, I tried revving the engine and it was very choppy - not dissimilar to how my 924 was when the engine was badly out-of-tune. In fact, one has to coax it up to 3000 with light pressure on the accelerator. If I press the accelerator any further, say halfway or beyond, the revs drop massively although I have not managed to stall the engine. The engine really struggles though and there were a couple of occasional clanking noises coming from under the bonnet as it did.

The car has never done this before.

What on earth has gone wrong? [&o]

 

[Diver944]

Sorry to hear this Dan []

Apart from the usual: plugs, plugleads, distributor cap, coil, fuel filter etc the only similar problem I have had is when my S2 had similar problems that turned out to be the failure of the engine temp sensor. This fooled the DME to thinking the car was always cold so it richened the mixture so much that any touch of the accelerator caused jerkiness and black smoke from the exhuast plus a nice strong smell of petrol.

You mention you should have 30 miles of fuel, this means you must be pretty low with the fuel light on, are you sure it's not fuel related?

 

[danmason]

By '30 miles' I meant 30 miles until I would normally be sweating and looking for a garage - the red light only came on 10 miles ago, which wouldn't normally cause me a problem. I will be topping it up from the petrol can in the morning though, just to be sure!

Interesting point about the temperature sensor. I also wondered whether the problem could be AFM-related?

 

[Big Dave]

Wow you must run your car pretty low on fuel ..
Ive NEVER had my fuel light come on.........

In fact how much "should" be left in the tank when the light comes on ???Anybody know??????

 

[Fen]

Plenty. I always wait for the light and frequently do 45 or 50 miles with it on.

 

[danmason]

Yeah, according to the manual there should be 10% i.e. 8litres left in the tank when the light comes on.

 

[colinbythesea]

My fuel light comes on at the quarter tank mark and has about 10 miles in it before it runs dry.

On Dans problem. Could a belt have slipped? Is it giving up or just starting to run rough? Mine tried to shake itself to pieces at abot 3000 revs when the balancer belts slipped.

 

[Fen]

ORIGINAL: colinbythesea

My fuel light comes on at the quarter tank mark and has about 10 miles in it before it runs dry.

Different dash / gauge.

 

[SianB]

I had a similar problem with my 924S except mine would stall. It turned out to be the cold start sensor. I got a new one for about £30 and it took me about 2 minutes to fit.

Sian

 

[jr2015]

before you start looking at the more exotic causes ,check the pressure at the fuel rail,I found it was the inlet side pressure regulator causing the problem(they`re the two cans on top of the fuel rail).Hope this is helpful
jr (replying to Dan rather than Sian)