Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: Varche on 30 May 2010, 15:48:35

Title: Misfire saga continues, stored codes.
Post by: Varche on 30 May 2010, 15:48:35

Fitted a known working S/H DIS pack. The misfire is still there!! Particularly under load (hills or acceleration). Revs fine stationary. I am 99% sure I have put the leads back on in correct order. The old DIS pack looked as new too.

Did the paperclip test and the codes are 21Throttle Position Sensor (TPS) Voltage High 73 Mass Air Flow Sensor Voltage Low and 57Idle Air Control Voltage Low.

Before changing the DIS pack, I tried with the MAF discon to see if it ran better - it didn't. so maybe those codes are a legacy from that as I haven't done 20 or so clean starts.

To date I have had the plugs out, all look the same and were new 4 years ago (say 6000 miles). It had new leads then too and a new DIS pack.
I had a look in the dark and saw a faint amount of blue tracking on plug lead no 5 so I changed that this a.m. for another lead. Still the same.

Is there anything else that could cause a misfire?  Poor seals on plenum after cleaning? Stuck lifter? Blocked fuel filter? Partial Vacuum in petrol tank (I'll try the car tomorrow with fuel cap off!)?

I'm really clutching at straws. As ever the car is gutless and runs like a tractor  ;D ;D ;D

Any suggestions please?

Title: Re: Misfire saga continues, stored codes.
Post by: JamesV6CDX on 30 May 2010, 15:50:49

1) stop driving it. The unburnt fuel will kill the cats

2) how do you know the DIS is OK? And didn't maybe get damaged on it's trip to Spain?

Varch - check for a spark at each and every plug.... individually...

Title: Re: Misfire saga continues, stored codes.
Post by: Varche on 30 May 2010, 15:53:39

Quote

1) stop driving it. The unburnt fuel will kill the cats

2) how do you know the DIS is OK? And didn't maybe get damaged on it's trip to Spain?

Varch - check for a spark at each and every plug.... individually...

Might be too late for the cats. What are the symptoms of "dead cats".? Is it just an MOT failure or do they fail and affect the cars performance?

Great suggestion for the spark plugs.

I don't know the DIS pack is OK but it was very well packed.

Title: Re: Misfire saga continues, stored codes.
Post by: Varche on 30 May 2010, 19:28:56

Great news.

Cyl no3 wasn't firing. That was a plug lead. Now working fine.

Still interested in the cats question though. How many hours of misfire can they take before being US and presumably they are then MOT failures?