Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: footloose on 09 July 2009, 17:43:18

Title: v6 engine misfire
Post by: footloose on 09 July 2009, 17:43:18
I recently had a problem with engine misfire and revs all up and down with a lot of spluttering when driving.
I was advised that it could be the crank sensor so i changed it. The car had never been better , for a while,
The darned thing has started again, the revs are all up and down on idle and when driving especially when it's warmed up it misfires and sputters all up the street.
I checked the cs sensor with my meter and seems ok.
I get a 31 on the paper clip test 3 times with the engine off. with the engine running i don't get any codes at all.
Has anyone got any further ideas.
The car is a v reg omega v6 facelift.
Thanks . :-[
Title: Re: v6 engine misfire
Post by: tigers_gonads on 09 July 2009, 17:50:35
check your plug wells for oil or water  :y
Title: Re: v6 engine misfire
Post by: Entwood on 09 July 2009, 18:03:49
Codes are correct .. 31 with engine not running is normal.

Was the crank sensor an GENUINE Vx one or a cheapie of ebay ??

I'm thinking crank sensor simply because things got better, for a while, after changing it. If it was HT side I don't see that a new crank sensor would have made any difference ...  :(
Title: Re: v6 engine misfire
Post by: footloose on 09 July 2009, 20:28:20
I will check the plugs for oil.
The cs sensor was an ebay one it could be faulty but when i unplugged it when the engine was running the engine stopped. Could this problem be anything to do with the timing? :-/
Title: Re: v6 engine misfire
Post by: V6drift on 09 July 2009, 22:45:14
i had a damaged HT lead that did this, only showed when hot too  ;)
it ran fine when oil soaked (before rocker gaskets changed) but when dried out, it ran awful  :-?
Title: Re: v6 engine misfire
Post by: Entwood on 09 July 2009, 23:09:43
Quote
I will check the plugs for oil.
The cs sensor was an ebay one it could be faulty but when i unplugged it when the engine was running the engine stopped. Could this problem be anything to do with the timing? :-/

It is recommended to only use genuine Vx crank sensors ... others are known to cause problems. As yours ran well with the new CS for a short time I would highly suspect a dodgy pattern CS ... go for a new GENUINE one.

The CS gives the ECU the position of the crank.... so it directly effects the timing in a seriously major way !!!!!
Title: Re: v6 engine misfire
Post by: Zuffenhausen on 10 July 2009, 07:09:15
We had similar symptoms after cam cover gaskets were done, turned out one injector lead was not seated correctly.
Title: Re: v6 engine misfire
Post by: RossMk2 on 10 July 2009, 07:57:13
Just about to post in my own thread, im haing this touble too.

Genuine GM CS has done little more than 50miles now and the cars started misfiring & spluttering again!
Title: Re: v6 engine misfire
Post by: footloose on 10 July 2009, 17:42:39
Guess what. Probably not the right thing to do but i unplugged the airflow meter while engine running, made no difference at all.
I then did the same with the intake air temp sensor and the thing ticked over great, I plugged it back in and the engine was all rough again,I havn't tried driving the car with int air temp sensor disconnected yet but i'll try it and see what happens. I have not found any oil in the plugs but the plug lead under the cowl end near the diss pack may be damaged.  :o
Title: Re: v6 engine misfire
Post by: footloose on 11 July 2009, 13:08:27
Today i drove the car with the air temp sensor disconnected.
It drove very well,. I got a code as expected but code 73? I checked twice and got the same. Now i am realy confused.
Iv'e ordered both the maf sensor and the temp sensor.
Is this going to work i wonder or am i off to some thing else. Any suggestions? :-/
Title: Re: v6 engine misfire
Post by: footloose on 11 July 2009, 13:12:18
Rossmk2,
Ishould wait before trying anything expensive. See what happens when iv'e done mine, if you can wait that long.
probably 4-5 days.
Title: Re: v6 engine misfire
Post by: footloose on 15 July 2009, 16:25:10
My inlet air sensor arrived yesterday and fitted it . drove a few miles today and everything seems ok. No missing or juddering when driving off. when the maf arrives I'll fit it anyway. thanks everyone for your help. very much appreciated. :y
Title: Re: v6 engine misfire
Post by: RossMk2 on 15 July 2009, 16:57:36
as i said in your other thread, i unplugged the Air Temp Sensor and it didnt do a thing, if anything it was worse. No EML either.
Title: Re: v6 engine misfire
Post by: footloose on 26 July 2009, 15:40:31
Rossmk2. I'm convinced that this prob is in that area but i'm a bit of a novice on these engines. Best to start a new thread and see what comes up. :y