R33 s2 1996 missfire

[Cohen]

R33 s2 1996 missfire

I brought this car 2 days ago and between 5500 and 6000 rpm she missfires the owner before me had put spark plugs in the car that were 4 dollars each, i went to auto one and they said they should be 25 each the engine being a rb25det would this be why she miss fires??

Any help is appreciated!? thanks in advance 

[Cohen]

Also running 10psi boost

 

[admS15]

No, check the gap on the spark plugs. 0.8mm is what you want. The $4 spark plugs are fine,  BCPR6ES or BCPR7ES is what you want. If it still misses at 0.8mm your coilpacks probably need replacing. If its stock ecu you could be getting r and r. This happens if the ecu detects too much airflow and tries to protect the engine by dumping fuel in it. Try turning the boost down a bit to say 7-8 psi and see if the miss goes away. Try all that and report back, cheers. Buy some new $4 sparkies while you're at it and make sure you get the 0.8mm version BCPR6ES, not BCPR6ES-11

[33easy]

+1 for regapping plugs

I had the exact same problem after putting in cheap copper plugs and running 10 psi (felt like a spluttering and loss of power after certain rpm).

I gapped the plugs down to 0.8 and wrapped the coilpacks in electrical tape and the problem went away.

[Cohen]

I brought platinum plugs for it but and put then to 0.85, still missfires my dad said it feels like its not getting enough fuel going through it.. i have a apexi neo is there anyway i could control it through that

[Sklyn]

Did you do all that admS15 said? Do that first. He is a wise wise dude!

[89CAL]

Why on earth did you buy platinum plugs for it

[Cohen]

Im knew to cars mate aha, expecially japanese ones, and they said buy these ones at the shop so i did i have bcp ones aswel

[89CAL]

The shop said to get the expensive ones, who'd have thought it......

For future anyway, the advantages of Platinum are the longer service intervals (I think they claim 100,000km on the plugs) which makes them sound good. This is all well and good on a mazda 3, not so much on a modified Skyline. I perfer to change plugs more often so its cheaper just to get $2 copper plugs and change them more often

[Cohen]

Ive replaced them with bcp .8mm ones and swapped the coilspacks out and its perfect now no missfire thanks for the help much appreciated