Missfire 4.5k-5.5k Revs

[Skyline'zor]

Hi all,

Just imported a r34 gtt , its stock standard...done around 90,000.... just recently if i've got my foot planted it missfires pretty bad through 4.5-5.5k revs, and stops after that.... it doesnt do it if i accelerate more gently through those revs

Anyone have anyidea whats causing this?

Cheers

[ZXY]

my first thoughts are coil packs. but could be something else too...wouldnt hurt to check your spark plugs

Edited June 13, 2010 by ZXY

[Neuroglider]

yeah common 34 problem dude, i had to do that in previous 34

coilpacks and change spark plugs at the same time! 0.8mm gap is good should pur like a kittin after

[Skyline'zor]

easy enough to do myself? what brand or coilpacks/ spark plugs?

[ZXY]

you prob can do it yourself, splitfire coilpacks and ngk plugs are the way to go.

[Dani Boi]

Splitfires are a bit of a rip off now, around $600+ new from memory. Might be better off trying to source some barely used second hand ones from this forum, or alternatively go with a different brand.

Edited June 13, 2010 by Dani Boi

[Slowpoke]

Try checking for a dirty air filter too.. that made mine misfire last time

[Skyline'zor]

600$ !! thats lame. let alone if i get somewhere like x-speed to do it, probably cost me around a grand =/

[Skyline'zor]

where can i get the coilpacks/ spark plugs?

[ZXY]

do a search on the forum, as for spark plugs you can either buy at your local supercheap auto or there is another forum member that sells it.

[Wogan]

i had a very similar problem once, and despite everyone telling me it would be coilpacks, it turned out to be a bad connection to the CAS..

my suggestion is not to go out buying a bunch of gear you may not need.. take it to one of the garages from the consolidated workshop thread and they should be able to tell you the cause pretty quickly and it will save you money in the long run.

[3LGODZILA]

before you buy new coilpacks if u wanna save some money (this isnt a permanent fix) change your spark plugs and gap them to about 0.75mm - dont go less then 0.7 and dont go more then 0.8. sometimes this will stop the missing

[Chris34]

600$ !! thats lame. let alone if i get somewhere like x-speed to do it, probably cost me around a grand =/

WOW! You got a Skyline and don't even want to pay $600 to repair it? Skylines are money pits, get used to it. Wait til your clutch goes...and even better wait til the turbo dies on its hole.

Bit of advice, if you don't want to pay workshop markup on parts, source out the parts yourself and just pay the workshop for the labour. Will save you quite a bit in the long run.

[XxNinjaxX]

I'd be pulling out my plugs and checking the condition/replacing them. is the engine running higher than standard boost? if not re-gapping shouldnt be required. if that fails being the next cheapest option i'd do a upper cylinder purge (u.c.p.) personally i use a product called "injector max" to ensure the injectors are clear and fueling properly and the back of the valves/piston heads are clean, just did one today on my R33 and can really feel the diffrence it made! If that doesnt fix it i'd be focused on the coilpacks. (might be a good idea to buy just one known working second hand standard coil then swap it with the rest one at a time to see if this eliminated the problem as it could just be one dodgey coil pack behind the whole miss) it takes a little bit of time but its better than $600 for a set of splitfires ya know

[Skyline'zor]

Hey everyone,

Update on the problem

Thanks to everyone for their input but it turns out you were all wrong, took it to xspeed today and it turned out to be the AFM, i'm not 100% its fixed yet as its wet and i cant get traction, but seems better.