Miss Fire At Around 4000rpm

[R33 S2]

hey guys after cleaning my aac valve at around 4000rpm i get a miss fire. its like its hitting a rev limiter or something. i used to get a weird jolt after installing the fmic but thought that was normal. now its just loses power. any help would be much appreciated. thanks in advance.

[r32-25t]

sounds like coils r starting to go on it,

mine did that same thing, i regapped the plugs and it worked for 3 weeks til i had to bite the bullet and buy some splitfire coils

[Jem]

chances are the installation of the cooler has reduced the temperature of the intake charge, which has the effect of increasing the density of the mixture in the combustion chamber and now your 10+ year old coil packs are having trouble igniting this mixture. any increase in boost will also add to this problem..

basically your best bet is to wind back the boost a bit and go for a drive, if the misfire is gone, this most likely the cause of your problem, the easiest thing to do would be to pick up a second hand pair of coils from the forums, however these will also be time bombs waiting to go.

the best option would be to pick up a pair of split fire coil packs, i believe these are about $500..

i have also heard of people having limited success 'taping' there coil packs up to provide better insulation, and it also never goes astray giving the earths near where the thermostat housing is a good clean, as well as the main earthing straps between the engine and the chassis a clean too..

there is alot of information around the forums on this problem so search is your friend

hope this information helps

[R33 S2]

chances are the installation of the cooler has reduced the temperature of the intake charge, which has the effect of increasing the density of the mixture in the combustion chamber and now your 10+ year old coil packs are having trouble igniting this mixture. any increase in boost will also add to this problem..

basically your best bet is to wind back the boost a bit and go for a drive, if the misfire is gone, this most likely the cause of your problem, the easiest thing to do would be to pick up a second hand pair of coils from the forums, however these will also be time bombs waiting to go.

the best option would be to pick up a pair of split fire coil packs, i believe these are about $500..

i have also heard of people having limited success 'taping' there coil packs up to provide better insulation, and it also never goes astray giving the earths near where the thermostat housing is a good clean, as well as the main earthing straps between the engine and the chassis a clean too..

there is alot of information around the forums on this problem so search is your friend

hope this information helps

its just weird how it got worse after i took off the aac valve for cleaning. maybe just bad timimng. ill look into these things. thanks alot