Rb20det Misfire @ High Revs

[NizmoNigga]

Hey SAU,

Just came across a problem few hours ago. Everytime i reach high rpms my car would start misfiring. When driving the car normally it is totally fine but as soon as i go to give it a bit of a squirt then it will start misfiring between the range of 6-7000rpm.

This video i found on Youtube is exactly what is happening

[shibby69]

spark plugs and coil packs man, i got a similar issue, might need to gap the plugs down or change the temp range if you just upped the boost a lil bit

[NizmoNigga]

Hey Jesse, cheers for the reply.

What is the chances it could be the spark plugs if it was changed 3 months ago by my mechanic which he would have gapped properly as he got it tune by another tuner on his dyno. Andy from Autosolutions done the work. So i will check to see if it is coilpacks.

Thanks

[lagperformance]

coil packs or too much timing more than likely coilpacks dying under load and causing detonation

[NizmoNigga]

Just took it for a drive and it doesnt do it anymore I didnt even check or touch the engine bay. Could it be that water didnt dry up properly even though i have the valley cover off? I had the car pressure cleaned hours before it started to problem..

[greensa14]

Could be boost leak? I had the same issue and was fine driving normal. Under boost it would misfire at high revs. I changed plugs, coils, filters, and ended up finding a hole in my cooler piping about the size of a tic tac. Fixed this and fixed the problem.

[bubba]

Just took it for a drive and it doesnt do it anymore I didnt even check or touch the engine bay. Could it be that water didnt dry up properly even though i have the valley cover off? I had the car pressure cleaned hours before it started to problem..

DO NOT put any water in the coilpack valley. Most likely this was the problem.

If it comes back, note what temp. the car is at and how long it has been driving. If it's heat related it could be coilpacks on their way out or the coil harness deteriorating. If it does randomly (not dependant on temp.) then I would be looking for a loose connection (earth wire at the back of the coil harness maybe or coil plugs falling apart).

This is what I mean by random.. the plugs on my coil harness were falling apart from the inside and intermittently breaking contact.

Edited March 22, 2010 by bubba

[Kazacoon32]

Could be boost leak? I had the same issue and was fine driving normal. Under boost it would misfire at high revs. I changed plugs, coils, filters, and ended up finding a hole in my cooler piping about the size of a tic tac. Fixed this and fixed the problem.

I've changed my coil packs with super spark ones i've changed my spark plugs with brand new iridium/platinum ones . . and the problems still there. . no water in my fuel . . i even put a sard fuel pressure regulator on it and changed the boost up and down to see if it makes a difference but nothing changed . . so ther was a leak from your intercooler?? maybe thats my issue . . ive tried so much to get rid of the missfiring its so annoying

[Willis]

I know this is a bump.. but this is my exact issue.

Off to get new spark plugs tonight.

[_x_FiReStOrM_x_]

Ignitor module failing can give similar symptoms sometimes. Don't overlook it.

[ae86 boy]

$100 its the coilpacks.

[KRECHR]

My problem was the igniter did this when I started running wasted spark... Couldn't Handel the double time!! Was worse when hotter but I would be checking the coil packs to! They will miss most heavily under max load

[Rolls]

More boost that stock due to large exhaust + intake mods = rich and retard, this plus bad plugs and or bad coils = misfire.

The richer the mixture the harder it is to ignite, the weaker the spark the more likely the flame will be blown out, so some combination of bad tune either from a stock ecu + more boost, or a retuned ECU too rich plus the stock ignition equipment shitting itself will result in a misfire, fix these things one by one and your problem will go away.

Cold weather will mean more air which means even richer mixture, but it means less heat in the coil packs so it may make the problem worse or better.

Edited October 20, 2012 by Rolls

[GTSBoy]

R32s don't R&R anywhere near as severely as RB25s. It's far more likely to be old ignition gear than anything else.

[Rolls]

My rb20 did it so bad I literally could not rev past 5500 rpm, it was like a rev limit, I've seen very bad cases with both motors, though it may well be worse with 25s.