Not Too Worried, BUT .....
 

Been away for a few days.

It's been freezing as we all know. I noticed something out of the ordinary on my Impreza, which normally only happens with a stone cold engine.

After a run the revs would stay at about 2000 RPM .... usually they drop to about 800 and sit there steadily with a warm engine.

A blip on the throttle brought the revs down to normal - but pretty slowly.

It's happened twice now .... as I said no great panic, just not normal.

My thinking was the MAF, but then also the Temp. Sensor may be getting confused?

It's a 2000MY Classic, with 90,000 miles - never put a foot wrong.

Any ideas? Thanks :D

I guess I am right with my diagnosis? As there are no hints to look elsewhere.

When my coolant termp sensor went the idle would fluctuate quite wildly on a cold engine but when upto temp was fine so i would guess it may be the maf.

Cheers, when it gets warmer I'll disconnect the MAF and see if it changes anything - thus ruling it out or in?

are you running a knocklink?

normally hunting idle or low idle speed for maf..

throttle cable snagging? the blip and off with then have vacum on the throttle butterfly and pull it shut rather than the gentle drop in throttle position?

or temp sensor as mentioned.. although I would expect it to fail fully pretty soon and see CEL and fans on and high idle speed.

other possibility is an air leak on manifold

Simon

No :D

Thanks for the reply Simon.

The wife thought there was a leaf caught in the air vent at the same time as this high idle speed incident, I noticed more wind noise than normal too .... could this point to anything? As you say, maybe a leak? - it does seem to have settled now, but still a bit high at 1100 RPM until it eventually settles at the usual 800 RPM.

possible the throttle cable needs oiling.. cable was tight in the shief and snagging and as you have used the car more it has freed up? or the throttle linkage etc..

Simon

I'll oil the return spring :thumb:

Cheers again ;)