Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: pigtown on 12 July 2010, 20:51:23

Title: 2.2 petrol splutters when starting
Post by: pigtown on 12 July 2010, 20:51:23
On starting in any weather and any time of day it splutters as if missing for a few minutes but when it settles it is fine. I can then stop and restart and no problem. I have changed plugs and rubber boots. cleaned the breathers but no better. It also has LPG and if I change to LPG when spluttering it runs ok.
So my suspicion is fuel related. 2.2 doesn't have an IACV so it's not that. Any ideas?
Title: Re: 2.2 petrol splutters when starting
Post by: alexandjen on 13 July 2010, 21:59:15
Did you clean the throttle body when you did the breathers?

http://www.omegaowners.com/forum/YaBB.pl?num=1162397695
Title: Re: 2.2 petrol splutters when starting
Post by: TheBoy on 13 July 2010, 22:27:09
if you use it on petrol for 20 or 30 miles, is it any better?

(wondering if lpg calibration is out, dragging in excessive fuel trim that buggers up petrol running)
Title: Re: 2.2 petrol splutters when starting
Post by: pigtown on 14 July 2010, 13:28:14
I did clean the throttle body and it was quite dirty!

Once I start going it seems to clear up whether on petrol or LPG, although LPG seems to run better than petrol so maybe it is something to do with the set up.
It is only a mixer LPG.

Once it's cleared I can stop and start up again with no problems - which makes it difficult to fault find!

When I changed the plugs I noticed the front one was a different coulour to the rest and that is why I changed the boots in case it was arcing.
Title: Re: 2.2 petrol splutters when starting
Post by: pigtown on 15 July 2010, 19:24:32
Is the MAF used when running LPG?
Title: Re: 2.2 petrol splutters when starting
Post by: alexandjen on 15 July 2010, 19:29:49
Quote
Is the MAF used when running LPG?

Yes it is used continuously as the air intake is flowing through it, you could try cleaning it or unplug it and see if there's any difference
Title: Re: 2.2 petrol splutters when starting
Post by: mark.adams on 15 July 2010, 20:32:00
Mine does this too (when it works) same type of LPG too...
Title: Re: 2.2 petrol splutters when starting
Post by: pigtown on 17 July 2010, 11:42:22
Mark - Same model of Omega as well I see.
Is there an inherent problem with the 2.2 petrol?
Title: Re: 2.2 petrol splutters when starting
Post by: tunnie on 17 July 2010, 11:46:37
No, mine is sweet on gas or petrol, Done 10k on gas in last few months
Title: Re: 2.2 petrol splutters when starting
Post by: pigtown on 18 July 2010, 11:17:50
Mine used to work ok on petrol. This problem has been going on for only a couple of months now.
Title: Re: 2.2 petrol splutters when starting
Post by: mark.adams on 18 July 2010, 18:52:05
I replaced the MAF with a measure of success...
Still not perfect, head off for skimming at the moment, i'll let you know how it performs when its back together in about a week or so.
I think the 2.2 has a lot of inherent problems sadly.
Title: Re: 2.2 petrol splutters when starting
Post by: pigtown on 19 July 2010, 18:53:13
I had the head replaced a while back - it had split so not just a gasket.
Strange how mine runs better on LPG than petrol as I thought LPG picks out any faults.
Title: Re: 2.2 petrol splutters when starting
Post by: mark.adams on 19 July 2010, 20:07:05
Same here, my lpg is a mixer system and therefore doesn't use the vauxhall ECU, i think it must hook into the MAF and Exhaust sensors
Title: Re: 2.2 petrol splutters when starting
Post by: tunnie on 19 July 2010, 20:12:49
are you loosing any coolant?
Title: Re: 2.2 petrol splutters when starting
Post by: pigtown on 20 July 2010, 19:02:10
I do lose a small amount of coolant.
I need to top up about every month (1500 miles).
How is this linked to petrol but not LPG?
Title: Re: 2.2 petrol splutters when starting
Post by: RobG on 20 July 2010, 19:42:32
Quote
I do lose a small amount of coolant.
I need to top up about every month (1500 miles).
How is this linked to petrol but not LPG?
Possible head gasket leak & coolant entering bore/s hence lumpy initial start-up
Title: Re: 2.2 petrol splutters when starting
Post by: Marks DTM Calib on 20 July 2010, 19:53:36
To little coolant loss to be honest.....cam sensor can cause similar issues
Title: Re: 2.2 petrol splutters when starting
Post by: RobG on 20 July 2010, 19:58:41
Quote
To little coolant loss to be honest.....cam sensor can cause similar issues
Quite possible. IIRC OP was having cam sensor problems. Pigtown, did you get round to changing the sensor when Nigel (Entwood) read your codes :question
Title: Re: 2.2 petrol splutters when starting
Post by: tunnie on 20 July 2010, 20:01:31
As Rob mentions above, i was wondering if coolant was entering the cylinder bore's as that was the early symptoms on father T's 2.2 failing, it would splutter on start-up, but soon clear, as it burns off the fluid. But as its every 1,500 miles thats not enough to indicate that kind of issue
Title: Re: 2.2 petrol splutters when starting
Post by: pigtown on 20 July 2010, 21:01:52
I hope it's not the headgasket and the fact it runs well as soon as I switch to LPG I think discounts that.

RobG I forgot about the cam sensor fault Nigel picked up. We thought it was a rogue reading as it only showed once and at the time I never had this problem.

I think I'll get a new cam sensor at the weekend!
I'll update as to if that fixes it.
Title: Re: 2.2 petrol splutters when starting
Post by: pigtown on 30 July 2010, 16:18:18
Fitted a new cam sensor and it worse than ever!
Now wants to pull away in top gear and throttle doesn't always respond. Now undriveable!
I bought the sensor from vauxhall-car-parts.co.uk as it advertised genuine vauxhall parts. I am suspicious as the original had a GM mark but thie new one has none at all.
I'm going to have to put the old one back on and start again....
Title: Re: 2.2 petrol splutters when starting
Post by: mathewst on 30 July 2010, 16:33:17
This probably is not the genuine cam sensor.
The same thing happened to me, I got a sensor error put a replacement one and the car became  nondriveable.
Read somewhere that cat problems can cause issue with cam sensor.
How much did you pay for sensor?
2.2 ones are expensive (in excess of 60 quids)
Title: Re: 2.2 petrol splutters when starting
Post by: pigtown on 30 July 2010, 16:43:36
I paid £50 and it was advertised as genuine so if it isn't i will be having words with the supplier!

Just tried disconnecting it and the car runs the same (bad) with NO sensor.
Title: Re: 2.2 petrol splutters when starting
Post by: mathewst on 30 July 2010, 17:04:49
Apparently replacement sensors work more or less fine on other engines but don't work at all at 2.2.

Title: Re: 2.2 petrol splutters when starting
Post by: vic on 01 August 2010, 11:22:56
Sounds identical to the problems I chased round my Omega for weeks. Rough tickover can be caused by a failing MAF. To check when cold switch off ignition, disconnect MAF and fire up again if it ticks over better then suspect the MAF (if you decide to replace only use genuine GM part though) Stealers prrice circa £112 bu you can source genuine elsewhere for £65 if you shop around.Tickover usually improves once the lambdas go closed loop after about two/thre minutes, which is why it only appears after start up. I replaced the cam sensor on mine, the part No for genuine part can be seen in this how to;
http://www.omegaowners.com/forum/YaBB.pl?num=1269023974
I would also check plug wells for oil or water, in the case of water check pots nearest skuttle. A leaking windscreen rubber allowed water to drip into mine. I hade recently removed the skuttle to attend to a blocked drain and wayward powersounder and hadn't reseated the screen rubber properly,once sorted, no problem. The MAF check is a no cost option so worth ten minutes to check it out as is the water in plug wells which can be sorted for a squirt of silicone sealant.
Hope you get it sorted
HTH
VC :y
Title: Re: 2.2 petrol splutters when starting
Post by: pigtown on 06 August 2010, 15:42:20
I replaced the cam sensor with a genuine one. Now runs again but the original problem remains.
Tried disconnecting MAF and after an initial splutter seemed to tick over better but not sure so will try again. once it's run for a few minutes it's ok so can't try again straight away.
Title: Re: 2.2 petrol splutters when starting
Post by: mark.adams on 06 August 2010, 17:58:40
I'd just like to second the only buy genuine MAF's, i tried a copy one, it ran as rough as a dog then backfired and blew the sensor straight off the side so i sent it back. One genuine MAF later and perfect running again...