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I'm having some problems when I go past around 4-4500Rpm after driving for a little while..

The car mis-fires and sputters ie. looses power.

I'm running 12.5psi making around 250rwkw on standared injectors, bigger fuel pump. exhaust,fmic,haltech e6k etc.

I searched and found that the problem might be the gap on my plugs is too big, so I gapped them down to .8. Worked when I went for a test drive, but still breaking down when I was out today...

Another thing, it has a custom intake plenum which has some small gaps around the gasket from not being tight enough on one side. And around number 6 injector doesn't have a tight seal and is sucking in some air..

could this be my problem?>

Any other ideas???

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If the car been running good on the injectors for a while i couldnt see it being that unless they are dirty....i would say it will be coil packs. If u have a mate who can help u out try there coil packs.

I don't want to sound stupid, but it has two "igntion" packs or something screwed onto the rocker cover. I'm guessing they are supposed to strengthen the spark or soemthing?

Or am I way off?

I don't know anyone with a set of coilpacks that I can try, what does a new upgraded set cost roughly??

I doubt any fancier type of plugs will fix the problem..

A member here at massive trouble he swore was his coil packs..turned out to be split wiring on the pack loom, causing spark to earth under load.

One way to check that is to remove the spark plug cover.. put it back together, wait until its dark.. give it some revs and try and spot any obviously arcs, or if you can see any jumps in the packs.

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