missfire..

[skyliner33driftking]

hi all i have a r33 gtst and have a miss fire underload around 4 / 5 k on rev range any ideas??

mods are full 4inch system
decat
induction kit
ngk ird 8 plugs
bleed valve and running 10 psi

i have just put another set of coil packs on but i am still getting the same problems??

[Boostjunkies]

if it's a spec 1 it could be the ign amp
but it could also be the coils still or coil pack wiring or an injector or fuel pump

[Stu C]

When you say another set of coil packs where they new ones or off a car runing the same spec as yours?

[Nismo]

Hi mine started doing this a few weeks ago then a few hours later it started cutting out soon as i hit i revs it ended up being the spark plugs the plugs were pritty new already only done around 6,000 miles ( so i really could not see it being them ) but it turned out the hot weather had killed them, soon as i put new plugs in it sorted the problem and the car is running how it should be i might be wrong but just an idea to check the plugs ??

[Flying Scotsman]

hi all i have a r33 gtst and have a miss fire underload around 4 / 5 k on rev range any ideas??

mods are full 4inch system
decat
induction kit
ngk ird 8 plugs
bleed valve and running 10 psi

i have just put another set of coil packs on but i am still getting the same problems??

With those mods the fueling and ignition timing will be all over the place which will exagerate any weaknesses with the ignition/fuel system. Splitfire coils are a good investment :icon_smile:

[skyliner33driftking]

hi the plugs are new and the coil packs are 2nd hand.
im goin to try and clean the afm but i think it map be the map .
its a spec 1 by the way. is there any one in the east midds who does ecu mapping for these ??? im in ilkeston / derby

[Stu C]

I would still say the coil packs. How old are the second hand ones?

[skyliner33driftking]

dont no but the trader who sold them said they worked fine but who no s

[Stu C]

You could try putting the boost back to stock. If that cures it then its more than defo a weak spark.

[Gambit]

Could still be rich and retard (overfuelling). When you up the boost and/or do stage 1 mods you will effect the airflow going through the AFM. If the air flow meter voltage isn't what it's supposed to be, at a given load point, according to the car's stock ecu then it will automatically increase the fuelling and retard th ignition timing to protext itself.

Lowering the boost will lower the AFM reading's and keep the ecu happy.
If it's plugs or coils, lowering the boost will reduce the load on them.

Does it feel like your suddenly driving into a massive headwind from 4500ish rpm to 6000rpm then goes back to accelerating like normal? Or is it a misfire, a popping/cutting out feeling?

[skyliner33driftking]

feels like its holding back and its poping and spiting flames

[Gambit]

Sounds like r&r to me, does it clear up a bit from 6000 to 7000rpm?

If I'm right your going to need some form of engine management, either an SAFC or piggy back ecu would do the trick. Personally, I'd leave the SAFC as while it will control the fuelling, the way it does it will throw the ignition timing out at the same time.

[skyliner33driftking]

yes it onll missfires around 4/ 5.5 rpm then clears up and pulls hard again.
how much is a remap goin to cost me??

[Gambit]

If you speak to Mark at Abbey Motorsport I'm sure he'll be able to sort something out for you in no time