Ford Focus - Jerky Throttle

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Sun 21 May 2006 17:53
Ford Focus - Jerky Throttle - psi
Hi, I have a problem that is more annoying than anything else.
The car in question is a Ford Focus 99/V 2.0l 16v Zetec.

When I am driving at a constant speed, say 70mph, and lift off the throttle for more than about 2 seconds, it is very jerky when throttle is reapplied.

I have tried hundreds of variations in throttle use, from "flooring it", down to easing power back *very* gently and progressively, and *every* time the car "lurches" back on the power again (seems more noticable when at normal operating temperature).

Is this a problem with the 2.0l 16v Zetec engine on 80,000 miles? It has clean air filter / oil & filter changed 2000 miles ago.

Any suggestions what may be causing this? P.S. I do not have this problem in any other car I have owned / driven so do not think it is my throttle technique!.

Thanks in advance
Pete.
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Mon 22 May 2006 11:18
Ford Focus - Jerky Throttle - 547HEW
Hi Pete,

First thoughts are sticking inlet valve(s) due to Supermarket petrol (no additives), or if spark plugs still originals, HT flash-over, which will leave evidence of tracking on the plug's insulator.

You have to change plugs and HT leads together, as the fit between the two is crucial.
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Mon 22 May 2006 14:50
Ford Focus - Jerky Throttle - kithmo
Most likely an air leak on the inlet side, check all vacuum pipes and joints.
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Tue 23 May 2006 14:37
Ford Focus - Jerky Throttle - Roly93
If this car has a throttle position sensor/potentiometer couldn't this symptom be caused by wear in the idling/low revs portion of the sensor be to blame for this ?
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