Hi, I have searched the threads for this problem (and learned a lot) but I would like a second opinion!
The car is a 1998 1.6 SX auto, 58000 genuine miles. The owner, a mate, says that it has begun "racing" while driving normally, the revs increase so much that he has to turn the engine off (being an auto) to slow the car, no warning lights appear though! When it does this he notices a petrol smell and sometimes a missfire, then it returns to normal again. I drove the car 10 miles today and couldn't fault it, it drove well. I have cleaned the throttle body and breather pipes etc but to be honest there wasn't that much wrong. He is a fastidious owner and even has me change the engine oil every 3000 miles so it worries him that the car is giving problems, could it be an injector spraying too much at times? I will test them tomorrow but it seems an intermittent fault and may not show with a test. Any ideas would be much appreciated.
Thank's in advance.

Pete.

Well as there have been no replies so far I cleaned the throttle body, idle control valve, tested the injectors which all read 15.6 ohms, checked the plugs and leads. Tested the car and it drives lovely so I returned it to the owner.
He reckons that the problem is that the revs suddenly rise to around the 4000 mark, the car starts juddering badly and then everything reverts back to normal! It has occured about a dozen times in the past year so the chances of it happening during test are very slim, it happens around town and also on the motorway. I wonder if it overfuels itself, he says that it smells "rich" when it happens, could it be the ecu, any ideas anyone please? Oh, and no warning lights appear. Got me baffled (which 'aint hard)!

Pete.

with it only being every now and then, then i'd say look for a damaged wire somewhere. if he goes over a bad bump/pot hole, then that could dislodge the wire and then it bounces, shakes back into place again.

make sense to me anyway.


same as the temp gauge on my escort... it works when it wants to. but have noticed bumps start it working and stop it working. not checked it yet, but i'm 90% sure it s a wire

If the revs are increasing first check for an air leak in the induction system.