Omega Owners Forum
Omega Help Area => Omega General Help => Topic started by: johndm1957 on 16 February 2007, 18:33:32
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My idle speed is just a small bit unstable, and if I've been say on cruise at 50 or 60, when I flick the cruise off, revs drop to 500/600 on overrun, then recovers to around 1500.
Any ideas chaps?
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ICV and breathers need a clean?
Fuel filter?
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Thought it might just be the air filter...choking the engine a little with high vacuum on overrun??
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As far as I know, if it is a 2.6 or 3.2 there isn’t much you can do mechanically as the car has Drive-by-Wire and the idle speed is electronically controlled by the ECU – i.e. there is no ICV valve to clean.
Air filter is tenner on TC, worth replacing annually in spite of Vx 2 and 4 years service schedule….
Check also for vacuum leaks, split or disconnected vacuum pipes, etc - any hissing noises?
Leaky exhaust manifold? You would have heard it if it did though…
Also, make sure that the problem is only while idling, and not under power – which could open a range of other possibilities such as coil packs, injectors, fuel filter etc.
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As far as I know, if it is a 2.6 or 3.2 there isn’t much you can do mechanically as the car has Drive-by-Wire and the idle speed is electronically controlled by the ECU – i.e. there is no ICV valve to clean.
Air filter is tenner on TC, worth replacing annually in spite of Vx 2 and 4 years service schedule….
Check also for vacuum leaks, split or disconnected vacuum pipes, etc - any hissing noises?
Leaky exhaust manifold? You would have heard it if it did though…
Also, make sure that the problem is only while idling, and not under power – which could open a range of other possibilities such as coil packs, injectors, fuel filter etc.
No sign of any vac leaks, smooth as silk when cruise engaged at any speed. Maybe I'm paranoid, the tach only moves a few RPM on idle, but my previous 2 Omegas were rock steady at idle. No hissy noises or exhaust leaks, but the dip/recovery of RPM on overrun is strange.
I guess 99% of people would'nt even notice!
I'll do the airfilter ASAP. Due for a service in July, and as one service is missing from the history, I'll get fuel filter done too... :y
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Throttle body needs a clean?