Hi all

 

Hope u can help! Got a weird problem with the revs dropping from idle. If stationary with the revs at about 900rpm (normal idle), then touch the throttle, the revs drop back to 500rpm for just a second (as if its about to cut out) then alls normal again. Seems to happen once the car's upto normal running temperature.

 

A similar thing happens if you back right off the throttle at speed, then accelerate again - the revs drop very slightly before rising as normal.

 

This can be quite alarming when pulling onto roundabouts.

 

I'm sure the fuel pump is noisier than normal too, although only audible from outside when the car's idling. Probably a red herring!

 

Anyone any ideas?

 

Cheers

 

Paul

TPS contacts maybe need a clean?

If stationary with the revs at about 900rpm (normal idle), then touch the throttle, the revs drop back to 500rpm for just a second (as if its about to cut out) then alls normal again. Seems to happen once the car's upto normal running temperature.

 

Isn't that a bit high for normal idle? Thought it was more like 750? I've had a similar problem with hesitancy and a lumpy pickup when moving away at low revs. Helped it a bit by cleaning throttle bodies a while back but this weekend I managed to get the pipes off one of the valves at the back of the plenum (AAC or IACV not sure which one to be honest) and squirted in a load of carb cleaner. It ran like a dog for a little while but is now soooo much better! Also the idle dropped to 750 for the first time since I've had the car!

 

Next job is cleaning the connectors to the valves to see if I can get the revs to drop a bit quicker - it seems sluggish getting down to proper idle levels

 

 

David