poor idling

09-14-2005, 05:10 AM
Hi There

I have picked up my car from having a radiator replace due to overheating and now I seem to have irratic idling.

It used to be rock steady at 1000 rpm but now it rocks between 500 and 1500. up and down all the time.

Any thoughts ?



02-11-2006, 06:07 PM
Not sure if you solved your problem, but you could try reseting your ecu.

10-18-2006, 06:48 AM
If the Twin spark engine is NOT idling OK (at about 900 rpm), but
suddenly go to about 1500rpm then down to about 500rpm then jump
between these values a couple of times then back to 900rpm.
The engine might even stall during this.

In most cases, there is an easy 10-minutes cure:

With a screwdriwer you loosen the spanner ring around the airintake-tube
at the point where it connects to the throttle-house.

Pull and bend the black intake-rubbertube a bit to the side and spray some
WD-40 onto the butterfly-valve. Let it work a minute or two, and then wipe
the inside of the throttle-house and the butterfly-valve with a clean cloth.

Oh - yes, you have to use one hand/finger doing the cleaning, and your
other hand/fingers pushing the top of the valve, so it opens and allows
you to clean up the inside. Would be nice with a third hand, though.

The reason for the erattic idle is, that over time the butterfly-valve picks
up dirt in the air-intake-tube. The dirt prevents the valve from completely
closing. The engine therefore gets confused thinking the valve is a bit
open (- thinks, that it is you putting your right foot to the pedal :) ).

You might have to reposition the idle engine to fix this completely after doing
the above. The way to do that is:
1. Insert key and turn to last position before start. Let it there for 90 seconds.
2. Then turn back off for 90 seconds (with key in).
3. Then start up the engine not using the throttle for a few seconds.

If this is not the cure, you can have a faulty idle speed motor and then
it has to be replaced.

10-20-2006, 01:56 PM
Does the idle only go up and down while moving with the clutch in, or does it also do it while you are stationery.

11-17-2012, 06:37 PM
Got the same issue on my 1.8 TS, tried cleaning the throttle body and it seemed better for a while now it idling erratically again, I think that it might be a icv valve, but not sure

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