my 2001 mk1 1.8 focus has this common over revving problem and i've half decided its the throttle position sensor playing up.seems a fairly simple problem to solve by replacing BUT having spoken to a local main dealers spares dept and describing the problem the guy on the 'phone said have you tried removing the fuse for a couple of mins because this sometimes resets the system BUT he wouldn't/couldn't tell me which fuse .....any ideas ?

Do you mean it over revs itself when idle or when changing gear? If its when idle then it may be the idle control valve but if its when changing gear then it will be the throttle position sensor.

Liam

[quote name='LiamZetec' timestamp='1291460453' post='105763']
Do you mean it over revs itself when idle or when changing gear? If its when idle then it may be the idle control valve but if its when changing gear then it will be the throttle position sensor.

Liam
[/quote]
hi Liam,its when i'm driving and it feels like an automatic,no need to touch throttle just goes by itself,when i come to brake and declutch the revs continue to build until i release clutch...last week it was doing this when i pulled up at traffic lights ,thought the engine was going to blow up!! all of a sudden it just went back to normal....had a look this morning no loose pipes that are obvious but it wont do it when at idle outside the house no matter how many times i rev engine....???

Yep sounds much like the Throttle Position Sensor needs replacing to me.

Liam

Hi Billy
take a look at attached.

tom

THANKS TO BOTH FOR YOUR HELPFULL ADVICE ,WILL HAVE A LOOK AT BOTH THINGS ASAP

I doubt it's an alternator issue as this will affect the battery and will cause the battery light on the dash to come on.

Liam

Hi, I had this EXACT same problem on my mk4 fiesta, over revving when changing gear and revving itself down the road. but couldent re-produce the results when parked no matter how hard I tried!! (VERY ANNOYING) lol

I scanned the car for codes and got "Throttle Position Sensor (TPS) Out of Range".
however you have to remember that this only tells you where the ECU detects the problem. not what is actually faulty.

I discovered that by unplugging the battery (this is probs to give the same effect as what the mechanic said to you) for 20 mins the car would then run fine for 3 days, but after that the problem would return and the car would need to be reset again.

I also discovered that by unplugging the tps the car would run rough but not over rev. Must be the TPS i thought?

I replaced the TPS but this did nothing, the car would still over rev when clutching in and drive itself down the road.

point of the story try changing the tps first as you can purchase one cheap as chips on ebay, but that might well not fix the problem. other things to consider are the wiring to the tps (if the pins are corroded it can affect the voltage and cause incorrect readings) or worst of all a faulty pcm (highly doubt that tho).

others stuggested at the time that it could be the idle speed control valve or vehicle speed sensor.


Unfortunately i never found a cure for the problem and after taking it to ford (who told me my car mat was getting caught OVER the pedal??!??!) and other garages (who couldent fix it) i ended up resetting the car every 3 days until it was written off (not my fault i might add )


hope this helps

[quote name='MrrNoName' timestamp='1291487821' post='105802']
Hi, I had this EXACT same problem on my mk4 fiesta, over revving when changing gear and revving itself down the road. but couldent re-produce the results when parked no matter how hard I tried!! (VERY ANNOYING) lol

I scanned the car for codes and got "Throttle Position Sensor (TPS) Out of Range".
however you have to remember that this only tells you where the ECU detects the problem. not what is actually faulty.

I discovered that by unplugging the battery (this is probs to give the same effect as what the mechanic said to you) for 20 mins the car would then run fine for 3 days, but after that the problem would return and the car would need to be reset again.

I also discovered that by unplugging the tps the car would run rough but not over rev. Must be the TPS i thought?

I replaced the TPS but this did nothing, the car would still over rev when clutching in and drive itself down the road.

point of the story try changing the tps first as you can purchase one cheap as chips on ebay, but that might well not fix the problem. other things to consider are the wiring to the tps (if the pins are corroded it can affect the voltage and cause incorrect readings) or worst of all a faulty pcm (highly doubt that tho).

others stuggested at the time that it could be the idle speed control valve or vehicle speed sensor.


Unfortunately i never found a cure for the problem and after taking it to ford (who told me my car mat was getting caught OVER the pedal??!??!) and other garages (who couldent fix it) i ended up resetting the car every 3 days until it was written off (not my fault i might add )


hope this helps
[/quote]
Replaced tps this am all seems fine now thanks for the help folks...mind you 68 quid at stealers and 20 on ebay is a bit of a difference don't you think?