Weird throttle problem 1.8 TDCi

[Steve_d]

Hello, hopefully someone can help to diagnose my problem.

Seems like the throttle is sticking, here's an example of what happens:

In slow moving traffic (1st gear), raise the revs to for example 2000RPM then let the throttle pedal come back but it doesnt - it keeps going at 2000RPM........until i dip the clutch then the revs return to idle (900RPM).

Seems really weird to me, its a little bit intermittent as well, and only happens in 1st gear and low speeds - engine seems to run a bit rough at that point as well until back to idle & then its fine.

Cheers,

Steve.

[SierraYankee99]

Dodgy throttle position sensor matey. You need to buy and fit a new accelerator pedal assembly from Ford. Around £65 and a ten minute job to change. 3 10mm nuts hold pedal to the car. You'll find it easier to use a deep socket. Remove these, the pedal lifts out. Disconnect the multi plug. Refit in reverse order. I'd suggest fitting the multiplug before bolting it to the car cos when I did mine there wasnt enough room to get it in after it was bolted back in. You only think you're getting it at low speeds and in 1st cos in other gears the car would just be slowly accelerating but something will be happening in all gears.

[Steve_d]

Thanks again! i'll go for that, well i'll try to get a second hand one - or is that a bad idea - are they common failures? should i go brand new?

[SierraYankee99]

Its a very common problem mate. I'd sport the money for a new one. In the long run it will pay off. The potentiometers in the pedal wear out over time as whenever the cars in use its being used.

[Steve_d]

Sorry to complicate this but on the way home i thought ahaaaaa - i have a scangauge II sitting here!! set it to TPS and when it was accelerating all by itself the TPS was zero? would that still suggest the sensor to be faulty?

Cheers,

Steve

[Steve_d]

bump - nobody any idea? :)

[SierraYankee99]

The only other thing it could be is a faulty fuel pump. Did the scanguage not give any fault codes?

[Steve_d]

Scangauge didnt pick any error codes up, you say the fuel pump but isnt it common rail, therefore the fuel delivery is controlled/timed electronically rather than by the pump itself?

[SierraYankee99]

Which leads us back the the thing that controls the electronic bit, that being the throttle position sensor in the accelerator pedal. When its doing it, try disconnecting the multi plug from the pedal assembly. If its not the pedal it should make no difference. Note tho, when you do disconnect it the heaterplug light will start to flash.