Hi, I have a KS Verada that has done 120,000 k and is generally well maintained. I have had it for 9 years and only tend to use it for short trips.

About six months ago it started to rev high at idle - about 2500 to 2700 rpm most of the time and then evey so often drop back down to about 800.

I took it to my mechanic but it would always be idling correctly while he had it, although one time when I went to pick it up from him it was racing but he was closing up and couldn't do anything at the time.

He suggested it was the stepper motor and replaced it.

The car was fine for about two months and then fell back into the high revving pattern with the occasional drop back to normal idle. To slow the revs a bit, when it is revving high, I close the adjustment at the stepper motor and this brings it down to about 2000. Trouble is when you have been driving for a while, say 10k or so, it drops back and stalls, usually at the worst time in traffic, because the revs are right down. When it does this I open up the adjustment and it idles fine for awhile. But at some time later, when you start it cold, it starts revving high again.

I took it back to the mechanic and he ran all the dignostics and said there was no fault showing and could not suggest anything he could do.

It seems to me that there must be something sticking open allowing air through and the high revving that eventually frees up when the car is hot.

Has anyone else experienced something like this or have any suggestions about?

Thanks

Mate, I am in Vic and do a lot of work on these cars, PM me if you are interested and I would be more than happy to have a look

I have a couple suspects but would really need to see the car first

That would be great, how can I get in touch with you?

I used to have that problem not all the time , was normal one day then high revs next day ..... then i replaced the entire throttle body and fixed the problem for me.

Good luck with it

i also have a similar problem, idles up in the 2k mark but when its in gear it drops right down to around 1k. ive adjusted the idle screw and got it down too 1000rpm but thats wound all the way, cant get it any lower.

Might just swap the TB, might be the TPS?

This is what I have been doing but I can only get it down to 2000, but then, when it flicks back, it stalls because it is too low to idle.

The consensus appears to be its the throttle body.

Thanks guys

As madmagna said, a number of things, but most likely ICV (Idle Control Valve) or TPS (Throttle Position Sensor)

Both Steve and r5pect, be aware that with the V6 you can't just adjust the idle dial, as the ISC (idle speed controller) will just try to compensate for what you do. The ISC needs to be bypassed before doing this, there's a bypass socket but not sure exactly how it's supposed to hook up.

Steve, just send Mal (madmagna) a private message by clicking on his name and using the menu that pops up. This is the best way to contact someone on the forums.

PS. 120K is pretty damn low, extremely rare to find a 2nd gen with those kind of k's. Though I guess lots of short trips can sometimes wear the engine more than fewer long trips...