Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: Andy B on 12 October 2011, 15:18:45

Title: Idle Air Control valve?
Post by: Andy B on 12 October 2011, 15:18:45
From cold my car starts first turn of the key (battery permitting  ::)) with no need to touch the throttle. However, sometimes when hot I need to feather the throttle to start it, otherwise it's very reluctant to start, once started though its runs OK. Also, sometimes after a long spell on the motorway, it wants to tick over at more like 1000rpm/1200rpm, a quick blip of the throttle will sort it. At Newent this year when Kevin W was playing on the Tech II with the IAC valve it did something similar re the revs/tick over. The valve has been off a couple of times & flushed out with acetone, no crap in there really, no 3-in-1 though  :-\.

Any thoughts? A N Other IAC valve? Another clear out?
Title: Re: Idle Air Control valve?
Post by: dbug on 12 October 2011, 18:27:29
From cold my car starts first turn of the key (battery permitting  ::)) with no need to touch the throttle. However, sometimes when hot I need to feather the throttle to start it, otherwise it's very reluctant to start, once started though its runs OK. Also, sometimes after a long spell on the motorway, it wants to tick over at more like 1000rpm/1200rpm, a quick blip of the throttle will sort it. At Newent this year when Kevin W was playing on the Tech II with the IAC valve it did something similar re the revs/tick over. The valve has been off a couple of times & flushed out with acetone, no crap in there really, no 3-in-1 though  :-\.

Any thoughts? A N Other IAC valve? Another clear out?

It really does need lubricating mate or there is a tendency for it to stick  ;)
Title: Re: Idle Air Control valve?
Post by: TheBoy on 12 October 2011, 18:40:00
If a bit of oil doesn't cure it, replace it :y
Title: Re: Idle Air Control valve?
Post by: Andy B on 12 October 2011, 20:37:18
I suppose that's the obvious answer .....  ::) ::)
I'll take it out next week some time, back in work tomorrow for 5 days  :(
Thanks  :y :y
Title: Re: Idle Air Control valve?
Post by: Kevin Wood on 13 October 2011, 00:01:48
IIRC the idle air valve was doing odd things on actuator test, like the revs increasing while the valve was supposedly being closed. Makes me wonder if it's had it. :-\
Title: Re: Idle Air Control valve?
Post by: bored bigyin54 on 13 October 2011, 00:08:29
i got a new one from vauxhall about 3 years ago for my old car it was a 2ltr cdxi about £120
Title: Re: Idle Air Control valve?
Post by: Andy B on 13 October 2011, 16:16:56
..... Makes me wonder if it's had it. :-\

I'm inclined to agree, hence the thread, but it won't get a new one. A second hand maybe.  ::) I'll see what lub'ing does - if anything.  :y
Title: Re: Idle Air Control valve?
Post by: Andy B on 13 October 2011, 16:17:31
i got a new one from vauxhall about 3 years ago for my old car it was a 2ltr cdxi about £120
It ain't getting a new one ......
Title: Re: Idle Air Control valve?
Post by: alexw80 on 14 October 2011, 07:51:37
i got a new one from vauxhall about 3 years ago for my old car it was a 2ltr cdxi about £120
It ain't getting a new one ......

Replaced mine with one from the scrappies for a tenner, sod paying £120 for new. Almost more than the car was worth lol
Title: Re: Idle Air Control valve?
Post by: Pete Elite on 14 October 2011, 15:43:12
i got a new one from vauxhall about 3 years ago for my old car it was a 2ltr cdxi about £120
It ain't getting a new one ......

  Hi Andy,
              I'm sure I've got one you can have for the cost of postage :y.

          PM me if your interested.

               Pete :).
Title: Re: Idle Air Control valve?
Post by: Debs. on 28 October 2011, 21:13:03
Did you sort out the idle-problem, Andy? :-\

Title: Re: Idle Air Control valve?
Post by: Andy B on 28 October 2011, 22:22:46
Did you sort out the idle-problem, Andy? :-\

Not had chance to have a play - work is all or nothing. I've another IACV to try now though &, weather pending should get chance over the week end. I'll let you know. :y
Title: Re: Idle Air Control valve?
Post by: Jimbob on 29 October 2011, 10:42:16
if you have the ability to check live data, look at the maf as well :y
Title: Re: Idle Air Control valve?
Post by: Andy B on 29 October 2011, 11:11:31
if you have the ability to check live data, look at the maf as well :y

Not at home  :( but I know a Captn who can  ;D ;D
Title: Re: Idle Air Control valve?
Post by: Tony H on 30 October 2011, 08:26:05
Make sure the throttle butterflies are closing properly had the same problem. for some reason the butterflies were out of adjustment even though the had not been tampered with. Slight reajustment now tickover sits rock solid at just over 500 rpm
Title: Re: Idle Air Control valve?
Post by: Andy B on 30 October 2011, 08:27:50
Make sure the throttle butterflies are closing properly had the same problem. for some reason the butterflies were out of adjustment even though the had not been tampered with. Slight reajustment now tickover sits rock solid at just over 500 rpm

Thanks Tony, will do.  :y
Title: Re: Idle Air Control valve?
Post by: Debs. on 30 October 2011, 08:52:42
Make sure the throttle butterflies are closing properly had the same problem. for some reason the butterflies were out of adjustment even though the had not been tampered with. Slight reajustment now tickover sits rock solid at just over 500 rpm

 :-\ Hmmmmmm?!?!?

The pup-mobile is still suffering low/no/erratic idle problems; despite having a new (VX) cranksensor, a replacement (known good) IAC, a replacement MAF, cam-belt change and a new set of plugs......I also diligently cleaned the throttle-body and butterflies (which were a bit cruddy from the EGR flow) and the breathers.
I noticed there are now a couple of other (current) forum-posts outlining the same symptoms that Andy (and I) currently have; what`s going on? ???
Title: Re: Idle Air Control valve?
Post by: feeutfo on 30 October 2011, 09:37:41
Also consider air leaks.
 Perished or damaged breather hoses, vac hoses, seated plenum, plastic bridge seals aaall that stuff.
 Icv air feed just bypasses the throttle to do a more accurate job the main cable throttles can't do. It adjusts to suit rpm required. I dont need to tell you all that, but It's a tiny amount of air. Any other tiny amount of air getting in from a leak will have an affect. Revs go up, so the icv cuts it's flow to try and steady rpm, but it takes such a small adjustment it almost stalls so opens to raise revs and on and on it goes with static idle.

So Debs yours sounds like a possible air leak. Although as with Andys, my old 2.5 icv took several very good soaks in carb cleaner before it behaved, not forgetting the light oil.  :)
Title: Re: Idle Air Control valve?
Post by: feeutfo on 30 October 2011, 09:39:54
Also consider air leaks.
 Perished or damaged breather hoses, vac hoses, seated plenum, plastic bridge seals aaall that stuff.
 Icv air feed just bypasses the throttle to do a more accurate job the main cable throttles can't do. It adjusts to suit rpm required. I dont need to tell you all that, but It's a tiny amount of air. Any other tiny amount of air getting in from a leak will have an affect. Revs go up, so the icv cuts it's flow to try and steady rpm, but it takes such a small adjustment it almost stalls so opens to raise revs and on and on it goes with static idle.

So Debs yours sounds like a possible air leak. Although as with Andys, my old 2.5 icv took several very good soaks in carb cleaner before it behaved, not forgetting the light oil.  :)
...on and on it's goes with erratic idle! Erratic! I meant.
Title: Re: Idle Air Control valve?
Post by: Andy B on 30 October 2011, 14:35:16
When turning the actual valve inside the original there was a slight sqeak as it moved  :-\

'New' IACV fitted with a little airline oil in it (best I could find other than 10W40  ::)  ;D) & so far so good.  :y :y
Title: Re: Idle Air Control valve?
Post by: Pete Elite on 30 October 2011, 21:48:23
When turning the actual valve inside the original there was a slight sqeak as it moved  :-\

'New' IACV fitted with a little airline oil in it (best I could find other than 10W40  ::)  ;D) & so far so good.  :y :y

  Glad it was OK Andy :y.
Title: Re: Idle Air Control valve?
Post by: Andy B on 30 October 2011, 21:50:12
When turning the actual valve inside the original there was a slight sqeak as it moved  :-\

'New' IACV fitted with a little airline oil in it (best I could find other than 10W40  ::)  ;D) & so far so good.  :y :y

  Glad it was OK Andy :y.

 :y :y thanks Pete