Took poorly car (Needed water pump  http://www.omegaowners.com/forum/YaBB.pl?board=GenChat ) to garage 1st thing, ran like a dream as per usual.  Someone in the office came home with me and took car back to garage.

Seems they have done a thorough job, put dyd in and did a leak test, went dor a test drive, did the job, even checked cam belts and advised on them.Had a little chat about other jobs, said he had tested it after fitting pump and no leaks, commented on how well the car drove and performed with out the back box on.  "Any problems give us a call" Cheers "Bye for now"

So as they were wrapping up I thought I would put in sport mode and TC off and leg it on a test drive.  Bit of wheel spin from the garage but also a misfire on full throttle.  Carried on, drives ok under normal load, just has a misfire on full throttle to about 2/3000 revs then is ok, changes gear and misfire comes back revs rise and it goes away  (Not paid too much attention to the exact revs the misfire cleared at)

Got back to garage he said the car sounde well but when I explained the misfire he jumped in and said that was the TC kicking in. etc etc

He went for a spin and agrees there is a misfire.  Had one of the plugs out and said they looked ok, looked at the leads etc, agreed to take it to see if it settled.

But with changing the water pump then what could he have touched that might cause the misfire.  The Plenum has been off and I am a torx head cover missing as well. 

TIA 

I would have thought that if there was an air leak it would be noticable as a lumpy idle

Can you hear the rear multirams kicking in Mr. S?

Misfire there when run from cold.

Also there from planting throttle to arrounf 4,500rpm

A lot better and smother when warm, but still there, only really an issue under full throttle.  Cant light the wheels up from a corner as I would be able to normally with TC off, just sounds like TC kicking in all the time.

Kevin Wood wrote on 18. Jan 2011 at 06:14:


Cheers Kevin

Would he have disonected or removed any part of the ignition to removed the plenum and do the water pump?

Just re -read that. Why take plenum off to do the water pump?

Mr Skrunts wrote on 18. Jan 2011 at 20:23:

Maybe they needed a plastic cap
If it was a VX dealer they might been have trying to find the water pump..

cem

Car is a 99 T plate 3.0 Auto Elite with all the toys.

Has done 90,250 miles, the last 7,000 with me and I will have had it 3 years at the end of April.

Never missed a beat, but the car has been stood for long periods and as a result corroded the front disks with rusting all the time.  So had genine Disks and pads and a new Vx Go battery.

Illness and lazyness means the car hasnt really been mainteined properly, but hopefully that will be rectified this summer.


Took the car out tonight to go pick GF up and didnt feel a noticable misfire as it was yesterday, had a bit of a blast round and looks like it may have cleared itself.  Took GF at 12:30 and from a standing start took it through the 1st 2 gears (1st time I have ever seen the rev counter enter the red) and didnt feel a miss fire.

Still have a water leak though, but nothing to  do with the water pump. (reckon it's from the HBV or that area.  But I am wondering if the misfire was from the amount of water sprayed from the header tank when the temp kept rising, and as the misfire was only ever under load then never showed up with the water pump problem as the car was driven with loads of TLC