Rb25det Missfire Woe's

[Simon-S14]

yeah ive searched, im well aware of the various problems of missfirings and their solutions. however read on. I just got my 25 package running in my 32, still running stock turbo and ecu, all it has is cooler, exhaust and a boost controller atm. Boost is set at 0.7 bar max. Now the car drives fine down low, and pulls quite clean and smooth until about 5000 rpm at WOT. above this it hesitates like a misfire would some times it even starts to clean up before getting worse around 6500ish.

the motor has new plugs, have inspected coil packs and all of them have their spings (no carbon ectrodes like RB20 plugs tho?) all are clean and not cracked in anyway.

not sure what else it could be?? any ideas?

Cheers

Simon

[MBS206]

What spark plugs did you put in?

My guess is that's the issue. Put in a brand new set into my mates car and it miss fired straight away. Problem: Wrong plug

[Simon-S14]

the ones recommended by sydneykid and many others, the 0.8 mm gapped coppers. forget the number tho lol

[Dale FZ1]

Visual inspection of coils MAY NOT show any obvious problems, other than soot/carbon/grime buildup that would lead to tracking. Try wrapping them with insulation tape.

Otherwise you could be experiencing the rich + retard syndrome. My R33 did, with nothing more than a 3 inch exhaust + pod + FMIC. No boost changes. Stock ECU said the mass-flow was too much and did something about it. Symptoms were much the same - ran fine down low, hesitating btwn 4600-5400 and then picked its act up and went much harder to redline.

Sounds like you have the correct heat range and gap for the spark plugs. Doesn't matter much whether they're copper, platinum or iridium. That just impacts cost and plug service life.

You could try to swap in a different stock ECU to compare, if any mates have similar vehicle.

[LatinR33]

rich + retard with just fmic,pod and exhaust?? thats odd. Sound like coils to me test em out and if u can afford splitfire coils will save u

[Simon-S14]

thanks for that mate, i'll pull the coils back out and try wrapping them. Its sure annoying!

Visual inspection of coils MAY NOT show any obvious problems, other than soot/carbon/grime buildup that would lead to tracking. Try wrapping them with insulation tape.

Otherwise you could be experiencing the rich + retard syndrome. My R33 did, with nothing more than a 3 inch exhaust + pod + FMIC. No boost changes. Stock ECU said the mass-flow was too much and did something about it. Symptoms were much the same - ran fine down low, hesitating btwn 4600-5400 and then picked its act up and went much harder to redline.

Sounds like you have the correct heat range and gap for the spark plugs. Doesn't matter much whether they're copper, platinum or iridium. That just impacts cost and plug service life.

You could try to swap in a different stock ECU to compare, if any mates have similar vehicle.

[Simon-S14]

well one of my packs had a hairline crack in it that i missed in the first inspection prior to putting motor in... so i put a layer of silastic over it, hope that does the trick!

[Ultimategtr]

hey man im in the same boat.. only when its cold tho and i see boost over 14psi..

iv got full 3.7inch exh from turbo with 5inch tip, apexi power flow, 6x3x80 fmic and factory boost solenoid(hi/low) 8/12ish.. on COLD nights hi boost creeps up to about 14-15psi and thats the only time i get misfire.. and sometimes if the engines cold and if i give it some stick.

i figure its my coils.. im sure its your coils as well.. to be honest.. save up for some splitfires aye.. get em for like 500.. till then nanny it or dont take it past 5-6k

[Simon-S14]

problem solved! put silastic over the crack and cleaned all the packs out where the spring goes in, now revs and pulls cleanly! thanks guys