My M12 GTO misfires

[rjb1975]

I wonder if anyone can help. I have just bought a 2002 Noble M12 2.5L.

Under heavy load acceleration and/or about 4-5000rpm the car starts to pop and almost cut in and out.

Does this sound like a problem with the second turbo? Am going to book in garage next week to inspect but it was fully serviced before i bought it.

Apart from the issue it is truly incredible the handling is like nothing else i have ever driven.


Thanks

[ThatPhilBrettGuy]

rjb1975 said:

Does this sound like a problem with the second turbo?

No.

Plugs, fuelling, vacuum pipe leak, exhaust cat collapse could be any of these.

[steve1]

Sounds like the plugs, just check the gap is not too big.
Steve.

[rjb1975]

steve1 said:

Sounds like the plugs, just check the gap is not too big.
Steve.

Thanks, I will check tonight when i get home.

Edited by rjb1975 on Thursday 15th May 15:39

[Adrian W]

hope it's not the ECU

[Ash 996 GT2]

Sounds like vacuum pipe at those revs, easily rectified.

[RobP]

ThatPhilBrettGuy said:

rjb1975 said:

Does this sound like a problem with the second turbo?

No.

Plugs, fuelling, vacuum pipe leak, exhaust cat collapse could be any of these.

yep - start with the easy, cheap(er) options first - vacuum pipe, plugs etc. Failing that, if you can get to the Essex area e-mail Yellowshed and arrange a rolling road session. It's the best way to id and fix these sorts of issues under load.
Also I would drive the car very carefully until it's sorted - if you have a fuel starvation problem you could damage your engine.

[JLSELAN]

Info in this thread may be relevant:
http://www.nobleforums.com/showthread.php?t=3417
It's possible that the misfire is associated with a lean burn condition, which may, in turn, be connected with a fuel pump problem (capacity and/or voltage). Note that the misfire rpm your seeing is pretty close to the point when peak boost is generated before it levels off at higher rpms.

[NobleGuy]

As has been said, take it easy on the gas until you know what the issue is. My misfire turned out to be one of the coil packs which was around £30 to fix, so it could be something really simple. Mine occurred at the same time of year as well - maybe the winter has gradually got to some element of the plugs or associated parts.

[Iaing01]

Sounds like plugs to me, the engine is very sensitive to the correct spark plug gap settings

Iain

[rjb1975]

Thanks for all the advice. The car has been in for work at garage and its the plug cables.

New parts are due any day ! Looking forward to its return and finally enjoy the car and it potential !

Edited by rjb1975 on Wednesday 4th June 16:32

[NobleGuy]

rjb1975 said:

Thanks for all the advice. The car has been in for work at garage and its the plug cables.

New parts are due any day ! Looking forward to its return and finally enjoy the car and it potential !

Edited by rjb1975 on Wednesday 4th June 16:32

That's good news. Should be reasonably cheap.
Hopefully the rain will hold off long enough .

[mgbond]

Did you go for the upgraded magnecor ones, help a bit with the spark and they look nicer in the engine bay .

Think I paid £110.

Bondy

[S26VE P]

Ended up putting these on the wifes impreza due to standard sets keep failing. not had a problem since.

[rjb1975]

Well I finally collected my car from garage with the plug cables replaced and aircon fixed (all under warranty). The sun was shining and I have experienced my noble for the first time running faultlessly.

What a car I am still lost for words and have bored my wife to death with all the detailed of why it’s the best car I have even own or driven. Both the performance and the handling are truly incredible. I am not sure there is much on the road that could come close.

I am hoping to do a track day end of July at Oulton Park will be able to experience car in a much more legal way!

Thanks for all the help and guidance to all on the problem that I had.