Misfiring On Full Boost

[BB81DO]

hey ..... i put my boost controller in today and wound the boost up to 14psi or there about

the problem is not that is misfiring on full boost then when i bring it off boost then back on it comes on then starts misforing again

is this a coil issue or is this the factory boost cut ??

[ahh 33 s2]

do u have aftermarket ecu?? sounds more like coil issue

[BB81DO]

nope ..... thats what i was thinking but i wasnt too sure

[nicr4wks]

33 coilpacks are notorious for going to shit, dumped a set of iridium plugs and supersparks in mine and misfire gone.

[BB81DO]

ive got NGK iridium plugs in mine with stock coils ........

so dump a set of coils in it and see how it runs after that

[payback21]

Std spark plug gap too big for higher boost. Pull the plugs out and gap them down to about 0.8mm

The spark gets blown out at higher boost hence the reason why its breaking down under full load. The spark jumps every were at the end of the plug causing it to not fire correctly. Do this and you will be ok.

[BB81DO]

ok then ...... i will give that a go and see how it goes

[boostn0199]

You will probably get away with just regapping your plugs to 0.8 but none the less your coils are probably dying so boosting it higher later on will bring back the missfire and also on cold weather it might still miss spitfires and plugs gapped at 0.8 ftw

[MUZT3K]

its your coil packs man, i boosted mine to 12 psi...couple weeks after bam...miss firing same as you.

[BB81DO]

regapped the plugs today ... helped a little so i turned it down to save it ....... until i get nw coils then i will dial some more boost in it

[Benzino33]

u got a stock ecu? u shouldnt run more than 12psi on a standard computer, or it hits R&R

[BB81DO]

R&R ??

[trel]

it's not a misfire. if youre running standard ecu, 14 psi is too high and you are hitting fuel cut. lower the boost to about 11-11.5 and you'll be perfect. don't boot it too much either as you'll damage your rings while it does that.

[Benzino33]

R&R ??

Rich and Retard. There sould be a thread somewhere here explaining fully what it is.. but yeh as explained above, its pretty much when the ecu senses too much boost coming through and cuts fuel supply to try to save the engine, causes the car to run absolute sh&t..but yeh just turn your boost back down and dont go past 12psi unless u got an aftermarket ecu or get yours remapped

[brentos]

Correct me if I am wrong, but I was pretty sure it adds more fuel to retard the ignition when the AFM senses too much air to rich it out? - not cut the fuel..

[defari]

http://www.skylinesaustralia.com/forums/Mi...500-t32356.html

^ that might help out aswell..

had the same problem, boost too high, turned it down, still slightly missfires on full boost but my coilpacks are just about shot... i taped/siliconed them up which helps but doesnt totally get rid of the missfire.. just waiting to get some more cash for splitfires..

[Pattygtst]

Correct me if I am wrong, but I was pretty sure it adds more fuel to retard the ignition when the AFM senses too much air to rich it out? - not cut the fuel..

correct

[rasonline]

is R&R the same as limp mode??