started car yesterday(MY00)and it was running rough on 3 cylinders and backfiring.Today put new plugs in(what a job)and still doing the same.Any ideas what the cause is?coils or MAF.
I had slight missfire at WOT in the past few weeks,but this is now really bad.

 

Same thing happened to me 3 weeks ago on my 99 car ( see shot engine below). After trying many things with no success, stripped the engine to reveal burnt out exhaust valves and seats and a scored bore (not to mention a toasted turbo too.)

 

Brutal Fred, but before stripping things bare, did you check HT leads??

 

Ar you running the standard ECU?

 

yes I am running standard ECU.Going to try disconnecting each injector and running engine to see which cylinder is giving probs.

 

Ski, it would be easier to pull the plug leads form the top of the engine than disconnect the injectors, could even be a lead breaking up thats causing the problem.

 

cheers RON,but problem now solved.I think it was spark plugs after all,as when I tried the car after changing them yesterday I had a bad connection on one of the leads.Rectified this and all is well.Took it out for a spin and the WOT missfire has gone too.Still not sure why the original spark plugs failed.They were only 5 months old under 3000 miles?

 

Glad to hear it was only a spark plug and not the same disaster as I had.