Club 80-90 Forums

What does fast idling mean and how do i fix it??? tried to find in wiki and search but got nothing of any use!!!
Will

Hi Will, fast idling (if it's not the adjustment thats out) usually means that the ecu temp sender is knackered. It's the one with the two pin plug, and is a general VW part. Expensive at VW at around 27 quid, but cheaper from German and Swedish.

Also the power steering sensor can cause a fast idle, but most likley the temp sender.

Also when the alternator kicks in big time the idle stabilisation gubbins fires her up a bit.

I seem to remember shorting the two contacts on the temp sender plug by joining with a wire, which simulates a hot engine, and that proved it was the temp sender on mine.

Simon.

Would this also apply to a 1.9 DG Water cooled engine. Mine has just developed the same symptons. Idling at about 1800 revs, this is on gas. I have checked to see if anything is amiss, breather pipes, pedal, airfilter etc, they appear to be ok.

Cheers

Phil

And now me too (1.9DG) - sometimes it is fast idling - sometimes it drops off to normal with a tap of the throttle.

Any ideas?

mikey9 wrote:And now me too (1.9DG) - sometimes it is fast idling - sometimes it drops off to normal with a tap of the throttle.

Any ideas?

Tapping the throttle tends to take the automatic choke off. At least it did with mine and me dads..........

Probably the throttle body is worn, and letting past too much air.
Really common problem on injection models, specially the higher mileage ones.
Take it off, clean it out, grease it up, check the idle/full throttle switch, refit it, warm it through and adjust speed with the big screw.