I recently joined this forum as in the process of getting myself a furby vRS as absolutly love them but am stuck with my fiesta 1.8 16v XR2i untill i can get my finance sorted out. I have a problem with the car at the moment and just wondering if anybody had any experience with the car at all.

I am suffering from jerking when i accelerate away from stand still and as soon as i am on the go it is fine but when i stop accelerating and drive along at a steady speed and reapply the accelerator it either seems to slow down a bit and hesitate as if fuel is a bit starved or it judders along not knowing exactly what it wants to do but if i put pressure down a bit more it suddenly kicks. This is a royal pain in the a**e as i live in cardiff and am more often than not stuck in traffic and for driving through traffic it is awful as cannot creep along as car just jumps and when doing 20mph and putting foot down a bit it just judders and then kicks as i mentioned which is the last hing i want when stuck in traffic as will end up shunting into the back of someone. :thumbdwn:

I have changed my plugs, leads, taken off k&n and put on original air box as it had a brand new air filter and a different MAF sensor, filled a hole in my exhaust and the problem seemed to get a bit better but is still there the majority of the time.

Any body have any ideas of what it could be? Somebody said maybe my ECU but hoping it would be something easier to sort out.

Any help would be much appreciated.

Thanks Carl.

Hi Carl

First thing that springs to mind is the throttle potetiometer. Dont know if yours will have a CTS or Colvern one. Basically, as the throttle pedal is moved, the output goes intermittent due to products of contact wear building up on the contact track. A diagnostics engineer should be able to check it out. Failing that, if you have a resistance meter, you should be seeing (If I remeber the PF2C envelope correctly) 2.2Kohms from pin to pin across the track. Slowly rotate the throttle valve and measure the contact output (the one that varies with throttle position). You should see a smooth change in resistance. If you get dropping out (ie the resistance keeps going infinite) then the potentiometer needs replacing. If the supplier is asking too much money and you have a PF2C with Colvern / AB Electronic build, drop me a PM. I have 400 of em in stock.

Edit: If you cannot get a continuous stable resistance across the main track, it is probably the CTS variant which had problems with the potentiometer end connections.

Chris

Thanks Chris. I assume the potentiometer is the throttle position sensor? Never worked on fuel injection engines before :( always had nice simple carburettors.

How will i be able to tell which type of potentiometer i have or will this be something i should get checked out by a diagnostics engineer?

Thanks again.

Thanks Chris. I assume the potentiometer is the throttle position sensor? Never worked on fuel injection engines before :( always had nice simple carburettors.

How will i be able to tell which type of potentiometer i have or will this be something i should get checked out by a diagnostics engineer?

Thanks again.

If you can get a decent photo and post it or send it over, I may be able to identify it from that. Out of curiosity, what date is the car? Parts I have go up to around 1995 cars.

Chris

I will take a picture in the morning and get it posted for ya. Car is a 1993 k plate. Just another note as well that i noticed earlier. When car is cold it doesnt stutter but after 2-3 mins it starts playing up. But from the sounds of it the throttle position sensor sounds likely to be the prob as is only there when put foot down slightly.

Just hoping isnt anything majorly mechanical as i split my cylinder head new years eve and have not got far past running in my reconditioned head. Roll on the end of Uni so can get my vRS.