Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: Markie on 22 July 2007, 14:53:26

Title: Whats causing my rough idle..
Post by: Markie on 22 July 2007, 14:53:26

Just done breathers, IACV, breather pipes, plenum, throttle bodies and all that Jazz..

Done it 5 times before on rough vauxhalls - every time it has the desired effect ( rock steady idle) so i know what i am doing here  :y

still have slight flctuation on mine....got to say - Bit like Broocies at the lakes everything was pretty much spot on and clean / clear..

So i wasnt surprised when on restart it was exactly the same TheBoy you heard this MV6 at laes so you will know what i am talking about at idle....the revs fluctuate by the width of the 500rpm dash on rev counter....must be 50 revs or so of a fluctuation....

Ive checked, rechecked, torqued everything, checked all cables etc and nothing is amiss.

Also no fuel consumption issues, no acceleration issues at any point and no starting issues.....just that 10% idle fluctuation...

thoughts?

Title: Re: Whats causing my rough idle..
Post by: Markie on 22 July 2007, 14:54:16

...also meant to say whilst iding i have no difference in idle speed when air con etc etc is on - im sure my revs at idle used to increase a few hundred.... :-/

Title: Re: Whats causing my rough idle..
Post by: Dazzler on 22 July 2007, 16:52:48

Have you tried replacing the IACV or just cleaning it???

Title: Re: Whats causing my rough idle..
Post by: Markie on 22 July 2007, 16:58:16

Quote

Have you tried replacing the IACV or just cleaning it???

swapped it out for a spare that was "known good"

Title: Re: Whats causing my rough idle..
Post by: TheBoy on 22 July 2007, 19:21:16

Knowing your skills, nothing to add really.

does seem to be airleak....  ....have you blanked egr? removed all intake stuff (red gasket knackered?) etc?

Title: Re: Whats causing my rough idle..
Post by: Chopsdad on 22 July 2007, 21:26:21

Quote

...also meant to say whilst iding i have no difference in idle speed when air con etc etc is on - im sure my revs at idle used to increase a few hundred.... :-/

My revs do go up with air con and fuel use increases from 0.2 to 0.3 mph at idle.  Mine ran odd for a while and then sorted itself out - I blamed the throttle butterfly.  Does sound like an air leak somewhere. :(

Title: Re: Whats causing my rough idle..
Post by: cem_devecioglu on 22 July 2007, 22:13:37

Hi,

in my idle problem throttle potentiometer solved the problem..May be this will help..

Also I remember somewhere else I read old lambda sensors cam make small fluctuations..

PS: Blocked EGR also effect the idle from time to time..

Title: Re: Whats causing my rough idle..
Post by: Markie on 23 July 2007, 15:44:07

Quote

Knowing your skills, nothing to add really.

does seem to be airleak....  ....have you blanked egr? removed all intake stuff (red gasket knackered?) etc?

not blanked egr...but will be doing so :y

Title: Re: Whats causing my rough idle..
Post by: Mike Collins on 23 July 2007, 16:54:58

Blanking the EGR certainly smoothed the idle on my wife's 2.5.
Does it start without opening the throttle? cam sensor fixed that one.

Title: Re: Whats causing my rough idle..
Post by: Markie on 23 July 2007, 20:06:13

Quote

Blanking the EGR certainly smoothed the idle on my wife's 2.5.
Does it start without opening the throttle? cam sensor fixed that one.

yep spot on in every other way Mike  :y