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[Andy H]

*Slight update...

I'm still on my hols but my mechanic had reported that a replacement MAF has been fitted, car is still almost undriveable! All codes cleared and no new ones are being produced which is bloody odd!! And very frustrating! 😩

Have the long term fuel trims been reset? (I think TB said that clearing the codes reset the trims but not certain  )

[P6UL K]

Everything has been cleared AFAIK, BTW this is only a generic code reader like a Snap-On device

[Kevin Wood]

Everything has been cleared AFAIK, BTW this is only a generic code reader like a Snap-On device

Hmm. Maybe, maybe not, then. I think the fuel trim tables get lost if you disconnect the battery on these, so it might be worth trying that. Disconnect and leave off for half an hour or so.

[chrisgixer]

*Slight update...

I'm still on my hols but my mechanic had reported that a replacement MAF has been fitted, car is still almost undriveable! All codes cleared and no new ones are being produced which is bloody odd!! And very frustrating! 😩

Replacement. New? Used? Genuine Gm?

[P6UL K]

*Slight update...

I'm still on my hols but my mechanic had reported that a replacement MAF has been fitted, car is still almost undriveable! All codes cleared and no new ones are being produced which is bloody odd!! And very frustrating! 😩

Replacement. New? Used? Genuine Gm?

No idea Chris, like I said I'm on holiday in Newquay currently so I'll find out more over the weekend upon my return.

Kevin - I'll disconnect battery also and try that 👍

[P6UL K]

Everything has been cleared AFAIK, BTW this is only a generic code reader like a Snap-On device

Hmm. Maybe, maybe not, then. I think the fuel trim tables get lost if you disconnect the battery on these, so it might be worth trying that. Disconnect and leave off for half an hour or so.

Just about to go and collect the car - if i can get it home, i'll disconnect the battery and leave over night to see if it clears the fuel trim tables

[P6UL K]

Car won't even run now! 

[zirk]

Car won't even run now! 

Wont run or wont start? any new codes since it was cleared?

[P6UL K]

Fires but struggles to run, runs briefly but then stalls.

Going to try my old coilpacks tomorrow even though they have started to break down

[zirk]

Any Relay or Throttle Body clicking when it stalls?

Is it pissing Fuel?, pop the fuel feed left off below Penlium (19mm one from Memory)

Did you get around to checking the below (Highlighted)?

Im trying to picture in my mind what would cause your sudden stopping (being slammed forward) during a miss fire, without any braking involved, the only thing I can think off is your miss fire is total Ing. fail (no spark on all pots), or as Al's thinking, total Fuel fail, although I would have thought enough fuel pressure left in the system to run it down rather than a complete cut out. May be not if being hammered.

I wondering if its worth checking and re installing the 2 ECU plugs and checking the main wiring  connectors under the battery, you could also swap the purple relays over, see if that does anything (if was me I would pop the covers off and have a look at the relay contacts), and generally checking, wiring loom, pushing relays fuses in the box.

Other thoughts, ECU??, I have had 2 go now on 3.2's without fault codes, one intermittent, the other total fail over night. 

[zirk]

Fires but struggles to run, runs briefly but then stalls.

Going to try my old coilpacks tomorrow even though they have started to break down

Any Codes Paul first.

[VXL V6]

Fuel pump?

[Andy H]

To recap - we don't know if the long term trims have been cleared, you have a new MAF fitted, engine runs like poop.

What does it do with the MAF disconnected?

[P6UL K]

Ok, just got back home with the car after a mission trying to get it to fire up.... Had a chat with my mechanic friend who confirmed that he had used a spare MAF with the same part No that he had in his box of odds'n'sods but the car ran the same with this fitted so he refitted the old one.

Had to jump the car as the batt was low, managed to get the car to start but it would not rev at all and idled really badly (make a machine gun noise with your tongue, it sounded like that!) After a few minutes it seem to settle and idle but wouldn't rev at all, so i unplugged the MAF and suddenly it revs like it should - freely!

So jumped in after letting it idle for 10 or so minutes (thankfully I only live four streets away from him) and pulled away, but no such luck! Car was misfiring again, couldn't pull its own weight and kept wanting to die so i was forever dipping the clutch, coasting so the engine would idle then building the revs up and bringing the clutch in to get some momentum.

Managed to get back to mine but it seems the issue still persists! I think i'll get another MAF from ECP for piece of mind and cross that off the list, i'll also disconnect the battery tonight to clear those fuel thingies and also get any codes, should there be any!

My only issue is while i'm doing all these things with the advice from you guys i am really in way over my head, I know the main dealer wouldn't have a clue and my local garage has done all they can with the experience they have.... Should i be looking at a specialist who would deal with mapping & ECU issues?

[Andy H]

Should i be looking at a specialist who would deal with mapping & ECU issues?

Maybe - the difficulty is finding someone who knows the Omega as well as the key people on OOF.

I think you have more than one issue which means that the fault finding requires an even more methodical approach than normal.

The symptoms described in your last post sound like a classic fuel starvation issue so fuel pump, fuel filter, pressure regulator and pipework all need to be checked and proven before being discounted.