Technical fast tickover multipla

[nigel jones]

petrol engine.Some times at traffic lights my cars ticking over realy fast 12 or 1300 revs,other times shes perfeckly, ok petol consumption is high about 23 per gal, what should i do please.

 

[BikeDoc]

Fast tickover multipla

High idle can be down to an air leak into the inlet manifold., maybe an air tube detached or holed.
Could also be something more mechanical, like a sticky cable, or something in the throttle body or mechanism, although that would more likely cause it to happen all the time.
Do the revs increase on their own (from a 'normal' idling level), or is it that they just don't drop down fully when you stop?
Do the revs (and speed) decrease as expected at other times, like lifting off the throttle at motorway speeds for instance?

 

[cheapomulti]

has this on our multi
turned out on ours to be the grommet that seals the brake vacuum servo to the pipe from the intlet manifold ... the seal had perished and was letting in air ...re-sealed with some ms polymer (it was a sunday afternoon and no dealer open) .... all sorted.