Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: Richard A on 11 February 2008, 17:19:40

Title: Irregular tick-over !
Post by: Richard A on 11 February 2008, 17:19:40

For no apparent reason the engine revs are hunting between 500 & 800rpm on tick-over, also when the engine is reved it slows down in steps ie 1500, then 1000, then to 800/500.
Once on the move no problems, no misfire, nothing, just smooth.
A bit pi!!!! off as it has been running so well, bloody Omega's  :(
Any idea's ?
regards
richard

Title: Re: Irregular tick-over !
Post by: Kevin Wood on 11 February 2008, 17:27:14

First things to do are to clean out the ICV, check the throttle is snapping shut properly and not binding open slightly (clean out the throttle body too) and check for air leaks.

Kevin

Title: Re: Irregular tick-over !
Post by: Richard A on 11 February 2008, 17:48:09

Cheers Kevin, I have cleaned the ICV but no change (it may be duff), will check throttle is closing next.  :y
regards
richard

Title: Re: Irregular tick-over !
Post by: cem_devecioglu on 11 February 2008, 18:19:00

As Kevin said check also for air leaks..

old o-rings under the plenum can leak..cheap to fix..

Another item to clean and check is EGR valve..

And try blocking EGR with a metal sheet..check if this helps..

if all those dont help the other fixes are expensive..

And from the RPM figures I see your ICV works..


I also observed that from time to time EGR opens too cool the engine..

This is mostly periodic ...(you can see when engine is hot)

Title: Re: Irregular tick-over !
Post by: Dave-C on 11 February 2008, 18:49:57

I agree ICV first, worth checking for VAC leaks too...

DC

Title: Re: Irregular tick-over !
Post by: Richard A on 13 February 2008, 17:52:02

Thanks for all the idea's, fitted a second hand IACV yesterday (from Issunaz - cheers) tick-over better but not totally smooth, checked for air leaks, things seem fine. Filled up with Shell V-Power today as I remembered I put 66 litres of unleaded on Friday over in Loughborough, maybe crap fuel. See what the next two days bring.  :(
regards
richard

Title: Re: Irregular tick-over !
Post by: Richard A on 15 February 2008, 15:12:19

Update. Tech 2 check showed 'Lean Lean' from the two mixture sensors ie very rich on tick-over. Checked all vacum pipes and breather connections all looked ok. However the third breather from the left of the four located on top but to the rear of the engine connects to a brass nozzle left side of the engine block, the rubber tube had perished and was sucking in air, cleaned the 1/8" hole in the nozzle then refitted new tube, tick-over 700 rpm and steady - Brilliant . Thanks for all the relpies. Many thanks to Dr Omega (Yahoo Groups) for the Tech 2 solution.  :y ;)
regards
richard

Title: Re: Irregular tick-over !
Post by: JiMbOb789 on 15 February 2008, 15:13:45

i used to have a Mitsubishi FTO that did that, something to do with the throttle cable