Still Missfiring

[Niksmo]

well long story short my car was missfiring so i got me some new coilpacks (splitfires) and plugs. i installed them both started the car and wallah it worked... until i drove it, now it missfires more then it did last time. so maybe it wasnt the coilpacks that where stuffed before?? dunno what to do now but im up for any sugestions to help me fix this problem :<.

its a R33 gtst series 1.5 with a series 2 engine

i used a 0.8 gap on the sparkplugs

and im also running a Vi Pec ecu (maybe the problem)

cheers

[30three]

check coil plugs are clipped in properly. clean AFM with brake cleaner or carby cleaner. thats all i got. could be dirty injectors or fuel filter

[Niksmo]

check coil plugs are clipped in properly. clean AFM with brake cleaner or carby cleaner. thats all i got. could be dirty injectors or fuel filter

AFM? and somebody did say somthing about the fuel filter..

[Neil Bakker]

Hey man

I presume you not running afm any more with the vi-pec?? when does the car miss fire? is it on high revs or at idle, what boost you running. if you running higher boost try and turn the boost down and see if its still misfireing. if it missfires on idle it may be something different and you could maybe allocate the missfire to a specific cylinder. need more info

cheers

[Niksmo]

Hey man

I presume you not running afm any more with the vi-pec?? when does the car miss fire? is it on high revs or at idle, what boost you running. if you running higher boost try and turn the boost down and see if its still misfireing. if it missfires on idle it may be something different and you could maybe allocate the missfire to a specific cylinder. need more info

cheers

ahh air flow metre lol. yeah the vipec has 1. im running 12 psi, it idles good at start up but when i drive (miss fires around 3000) and it missfires then i slow down to idle it missfire on idle. but if i have to spend all weekend again trying to figue it out ill just buckle down and do that.

[Neil Bakker]

hey man

does the car missfire if you take it up slowly, like not on full throttle or full boost or does it misfire from 3k all the time. this is a long shot but if it does missfire in any driving condition from 3k onwards there is a possibility that it could be fuelpump, not getting enough fuel preasure. just a gues

[Niksmo]

when i drive it normaly to 3k it doesnt missfire till i hit 3001 im still too scared to flat foot it. i do have a walbro fuel pump in there (installed profesionally afew months ago) so idk.

[gazza750]

boost/vacuum leak check your intercooler piping

[Niksmo]

boost/vacuum leak check your intercooler piping

yeah i checked that when i got home today.

cheers for the tips guys ill be sure to recheck everything this weekend

[R32 Driver]

Did you replace the coilpack loom?

http://justjap.com/store/product.php?produ...at=0&page=1

that thingy, known to get worn as it does sit ontop of the engine and gets heated up alot

[BROCKDOE]

I had similar problem. Replaced coils, plugs, re gapped em and after putting it all back together still had a missfire. Was late and I was frustrated so went to bed. Had another look in the morning, leant on a coil lead/plug a little accidently and it went away. So pulled it off, gave it a spray with some dewatering fluid and never had a problem since

[Ehgriez]

+1 for replacing loom.

i think they are about 150 from nissan.

might want to check what issues bubba had when his went to see if it matches up with your problem.

[colt75]

im guessing you tried changing your plugs b4 u forked out for splitfires?..

[Niksmo]

nope. but i was gonna get them anyway so i thort meh might aswell change them too. might even be the loom coz it was hella old and crumbly... lol.

wtb loom

Edited May 27, 2009 by Niksmo

[R33_NICK]

if the coilpack change and plugs didnt solve the problem, check the coilpack harness cause the wiring will start to fail after being exposed to 15-18 years of engine bay heat and check the igniter module as well. if you want i can get prices for you from our parts guy.

[colt75]

wait im confused now.

have youc hanged your plugs since it started to misfire?

[autoworx]

as the vipec runs a map sensor its not as sensitive to air leaks as an AFM based setup however it could still be that particuarly if its a bad one.

Most likely its electrical , so check harness as others mentioned .

but it also could be fuel , I recently had a GTR with faulty injector which under load would not give enough fuel therefore no ingition in that cyclinder . we checked the ignition system over and over until we figured it out.

and just to be sure double check your plugs , one might be fouled , electrode is broken or just not seated properly . I had a customer who sweared his splitfires were no good but it was a plug he had screwed in on about a 30deg wrong angle (aka on the piss)

[Ehgriez]

How do you manage to screw in a sparkplug on the piss? :S

Man if the wiring was old and crumbly, that's quite posisbly the issue. Think it's 150-180 from nissan.

[Wogan]

could be the CAS .. i had that problem once...

[autoworx]

How do you manage to screw in a sparkplug on the piss? :S

Man if the wiring was old and crumbly, that's quite posisbly the issue. Think it's 150-180 from nissan.

you just keep screwing in , when it gets hard to screw you screw harder!

+1 for CAS vipec wants a nice strong trigger signal where stock ecu doesnt mind as much . this is true on many aftermarket ecus many people upgrade their trigger systems. weve seen a couple of skylines now on the dyno with cas issues only apparrent with the ecu upgrade and the cas's are getting on now.