Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: mykd2007 on 22 April 2008, 18:56:31

Title: omega v6 struggles to rev over 3500....
Post by: mykd2007 on 22 April 2008, 18:56:31
I have a 3.0 v6 estate which has recently had a new coil pack, genuine gm leads and bosch 4 prong spark plugs. It ran fine until 2 days ago. It now sounds like it's missing on 2 spark plugs, and drives like a pig! It is just about bearable on very very light throttle (cruising on a level road). If I boot it (which is rare, as it  feels horrible), it accelerates up to 3500- 4500 rpm, and holds there for about 5 seconds, and then lets it go all the way to the redline. Any guesses???
Thanks,
Myk
Title: Re: omega v6 struggles to rev over 3500....
Post by: albitz on 22 April 2008, 18:57:59
have you tried the paperclip test for fault codes ?
Title: Re: omega v6 struggles to rev over 3500....
Post by: mykd2007 on 22 April 2008, 19:14:23
no, not yet, but there isnt any engine warning light. I will check later
Title: Re: omega v6 struggles to rev over 3500....
Post by: Markie on 22 April 2008, 19:19:54
there wont necessarily be EML illumination due to a mis fire..

In my experience I have still to see one that does come on with mis fire...

Were the breathers cleaned as the dispack etc was done and have you retraced your steps to ensure everything is still secure?

Also are cam covers free of water / oil ?
Title: Re: omega v6 struggles to rev over 3500....
Post by: Marks DTM Calib on 22 April 2008, 19:24:22
First question that springs to mind is does it occur on petrol, lpg or both?

Second is when was the petrol and LPG filters last changed?
Title: Re: omega v6 struggles to rev over 3500....
Post by: 106rallye on 22 April 2008, 19:37:55
What was the reason for you changing the plugs, leads and dis?

only reason i ask is that before i bought my omega, my mate who owned it before me had the dis pack replaced twice then it went again.

Turned out to be a faulty HBV (heater bypass valve) which was leaking water straight onto the dis (great design mr VX  :y). once this was changed (£30 part) and the dis again, the problem has never came back.
Title: Re: omega v6 struggles to rev over 3500....
Post by: mykd2007 on 22 April 2008, 20:33:05
Hi, I have just paperclipped it. It came up with 19. I changed the bits, due to the leads being crap copies which fell apart on the last plug change(champion I think), the plugs needed doing (as the LPG seems to eat plugs every 6000 miles). I have moved the coil pack. I custom made brackets for it. It sits near the water expansion bottle. I have checked the low tension side with a multilmeter. It has got an oil leak on 1&3 from the rocker box gasket. I have removed the excess oil, used carb cleaner on the insides of the leads, changed the spark plugs on 1 and 3. The problem is the same on petrol and lpg (slightly worse on LPG, but not much).

Cheers,
Myk
Title: Re: omega v6 struggles to rev over 3500....
Post by: mykd2007 on 22 April 2008, 20:36:16
forgot to add... no water leaks, and the breathers are clear (first thing I did when I got it). petrol and LPG filters done 5000 miles ago
Title: Re: omega v6 struggles to rev over 3500....
Post by: Marks DTM Calib on 22 April 2008, 20:39:58
Crank sensor is knackered
Title: Re: omega v6 struggles to rev over 3500....
Post by: mykd2007 on 22 April 2008, 20:42:02
I only changed it 10000 miles ago....and I rerouted the cable away from the exhaust.
Title: Re: omega v6 struggles to rev over 3500....
Post by: Marks DTM Calib on 22 April 2008, 20:46:05
Quote
I only changed it 10000 miles ago....and I rerouted the cable away from the exhaust.

Genuine or non-genuine?
Title: Re: omega v6 struggles to rev over 3500....
Post by: Entwood on 22 April 2008, 20:46:57
Quote
I only changed it 10000 miles ago....and I rerouted the cable away from the exhaust.

matters not ... 19 is crank sensor fault ....  :(
Title: Re: omega v6 struggles to rev over 3500....
Post by: mykd2007 on 22 April 2008, 20:51:24
ok, many thanks for all your help. I will get another one ordered now. The one on it is a genuine vx unit. It was replaced last time because there was no spark/injection on LPG or petrol, but that was code 31 (I think)
Title: Re: omega v6 struggles to rev over 3500....
Post by: Entwood on 22 April 2008, 21:56:06
31 is "no rpm signal" which is normal with the engine not running ......  :)
Title: Re: omega v6 struggles to rev over 3500....
Post by: MutantCav on 22 April 2008, 22:15:48
As above...31 will come up if the engine is not running...if you had the crank sensor changed because it was checked with the engine off...then you wasted your money most likely...but 19 is crank sensor knackered, end of...
Title: Re: omega v6 struggles to rev over 3500....
Post by: mykd2007 on 23 April 2008, 06:47:14
I may have been wrong with the 31. changing the sensor cured the problem, as it ran properly....before it wouldn't start at all.