Right, I've changed the spark plugs, done the new age coil pack conversion, 550cc Pink STI Injectors, but I still seem to get a slight miss fire around 2500-3000 revs

What else can cause missfire? I have changed everything I can think of?!

 

Plugs gapped properly?
Coil leads definately all leading to the right cylinders?
Injectors brand new? Or if old flow tested?

If exactly the same problem was there before and it is still exactly the same, as you say it would point to something else.

All I can think of would be ECU/electrical

Is the missfire when the engine is underload or not?
To be honest I would have done exactly the same as you and would now be a bit stumped too...

Steve

 

Plugs gapped properly yes, coil leads are fine (car run perfectly 9 times out of 10)

Injectors second hand, but flow tested.

Its only under load it miss fires some time, but its always around 2500-3000, but very rarely happens, can just feel it sometimes.

Confusing the hell out of me, just had it remaped by Duncan, had old coils on it when it was mapped and couldnt taken any more boost without miss firing, so changed to new age coil packs, and solved most of the problems, but out on track today I noticed it happening a couple of times.

 

It could be a fueling issue at that revs James - want me to take a peek next time I am up ? We could finish the map off to the boost levels we wanted to run last night too.

Up on the dyno in durham on the 5th Aug ...

 

I'll be there Duncan