Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: 05omegav6 on 20 July 2012, 12:41:24

Title: 3.2 V6 Misfire Update
Post by: 05omegav6 on 20 July 2012, 12:41:24

Changed both front O2 sensors for known good ones, cheers Rob :y

Light back on with 0420, 0430, 0300 and 0306 ::)

Will feed it on V Power over the weekend to see if that cures the first two, but stumped with the misfire :-\

I've changed the loom for a good second hand one, fitted new coil packs, changed the fuel rail, fuel pressure regulator, injectors and loom, throttle body, MAF sensor, ECU and front O2 sensors. Plugs are GM quads and are changed every 20k. No oil or water in the plug wells either.

Runs well, and pulls like a train. But it has a tendency to run rough when started, both hot and cold, but not consistently. Turn it off and restart and it's fine, so still think that the problem is electrical rather than mechanical.

Definitely better since the loom change last week, and more so since the O2 sensors... still has a slight vibration at idle, but this engine has never idled that smoothly :-\

Title: Re: 3.2 V6 Misfire Update
Post by: twiglet on 20 July 2012, 12:56:19

Al, are the 0420/0430 codes not being caused by the rear sensors because the pre-cats are failing?

I moved the rear sensors back to behind the main cats, following the guide on here, and I've never seen a fault code since.  :y

Title: Re: 3.2 V6 Misfire Update
Post by: JamesV6CDX on 20 July 2012, 12:59:15

what are the compression test results?

Any loss or cross contamination of fluids?

Any smoke from exhaust?

Has it ever eaten a plug electrode?

Title: Re: 3.2 V6 Misfire Update
Post by: Entwood on 20 July 2012, 13:01:47

Ignore the 420/430 .. just get them cleared then drive it hardish with decent petrol in for a week ..

The misfire is the problem, can you get any live data ???

Title: Re: 3.2 V6 Misfire Update
Post by: 05omegav6 on 20 July 2012, 13:06:32

They come and go on this one, light is normally on due to the misfire codes rather than cat ones :y moving the sensors is on the todo list, but not too close to the top :-X

Changed the front sensors simply to rule them out as I got a 0135, iirc, in the last lot which were cleared yesterday.

Four codes is a mahoosive improvement tbh ::) previous list started off summat like 0300, 0306, 0300, 0306, 0304, 0305, 0300, 0303, 0306...etc

Title: Re: 3.2 V6 Misfire Update
Post by: 05omegav6 on 20 July 2012, 13:10:16

Quote from: JamesV6CDX on 20 July 2012, 12:59:15

what are the compression test results? 8.9 - 9.2 bar

Any loss or cross contamination of fluids? Nope

Any smoke from exhaust? Nope

Has it ever eaten a plug electrode? Yup pot 6 ::)

Quote from: Entwood on 20 July 2012, 13:01:47

Ignore the 420/430 .. just get them cleared then drive it hardish with decent petrol in for a week ..  ::) this car gets more cane than a sugar factory, but usually on supermarket fuel tbh :-X

The misfire is the problem, can you get any live data ??? And now over to Kevin, our lead reporter in Alton...

Title: Re: 3.2 V6 Misfire Update
Post by: Kevin Wood on 20 July 2012, 15:02:21

Umm. :-[ Live data currently still in the Tech 2. ::)

I'll have a look. :y