car jolts

[webby73]

Hi I have a x type 2.1 and when I drive it it jolts once or twice then OK it normally happens when I slow down say when I'm in third gear then speed up or if I put my foot down hard. I have replaced the crank case breather pipe but it is still doing it I have no warning lights up at all and it starts and idles OK any ideas guys thanks.

[Jaguar Owners Club]

I would suggest plugging in a code reader to see if there are any fault codes in the Electronic Control Unit.

If so, perhaps a worn Throttle Potentiometer may be the cause

[webby73]

What is a throttle potentiometer what does this do and is it easy to fix and how much

[Old Peter]

Hi Deane,

 

It is a sensor [or something like that] that tells the computer the position of the throttle.  Decelleration or acceleration.  I think Trevor has got it spot on.

 

Before cars got sophisticated you just put some 3 in 1 Oil or WD40 on the throttle cable.

 

It is worth googling the words and there you will usually find a video on You Tube. 

 

Regards,

 

Peter.

[webby73]

Apart from that what else would cause the car to jolt its like a sort of misfire or starvation of fuel if you go up a hill and you are in say fourth gear the car will jump about until I change to third then will be OK its annoying .

[Jaguar Owners Club]

I think the only way forward is a quick scan of the Electronic Control Unit to look for any stored fault codes and go from there!