Missfiring Again!?

[da spike]

I have a problem with my car again its a R33 S2 and it is missfiring, I know this topic has been covered tons of times but I have fixed the missfire previously by buying new coilpacks. I bought JJR coilpacks and the missfire was gone for maybe 6 months, the car reved very smoothly all the way to redline... and now I'm getting a missfire at about 5000-5500rpm and up until then the car feels flat like it has no balls and then at about 6000rpm it feels like it takes off until redline.

Could this be that the coilpacks have fudged them selves?

Also I have replaced the spark plugs with iridium ones about 6 months ago just before i changed the coilpacks.

Any ideas? Could it be a injector?

[FLN75S]

Could be the fact that you plugs are not gapped correctly.

What gap are you running at the moment???

[geraus]

get BCPR6ES gapped 0.8mm

[FLN75S]

get BCPR6ES gapped 0.8mm

+1

[PIOTREK]

there is a sticky in general maintenance, they say to tape up your coils due to tiny cracks in them(electrical tape). Might be worth checking a very cheap option, at least the u can diagnose the problem this way.

[Benzino33]

there is a sticky in general maintenance, they say to tape up your coils due to tiny cracks in them(electrical tape). Might be worth checking a very cheap option, at least the u can diagnose the problem this way.

+1

Worked for me

[PIOTREK]

haha ben i thought u changed them to GTR ones lol

[da spike]

there is a sticky in general maintenance, they say to tape up your coils due to tiny cracks in them(electrical tape). Might be worth checking a very cheap option, at least the u can diagnose the problem this way.

I got new JJR coils, they shouldnt need to be taped...but i guess if it stops missfirring when they are taped then this just means they are arking out then they are fooked...

My plugs are gapped to the standard irridium plug size which is 12mm i think. But they shouldnt need to be gapped if i got new coil packs rite??? They should be strong enough to make the spark jump accross stock gapped spark plugs?

Edited May 22, 2009 by da spike

[TiTAN]

mine runs 1.1mm plug gaps fine if you tape the coils up and the misfire is still there see if you can borrow a friends coil pack loom as the plugs to the coil packs may be corroded.

[Benzino33]

haha ben i thought u changed them to GTR ones lol

lol yeah i did man, but same shit after a few months, so taping up fixed it

[a31lunacy]

change the plugs to BCPR6ES gapped to .8mm then put a little mark in texta on the spark plug where the electrode is open (ie where you can see the most of it) when doing up your spark plugs point that mark to the inlet manifold you would be surprised how often this will fix your problems you want the mixture to be ignited if the electrode is facing the exhaust manifold it wont run as well small point but makes a big difference

[da spike]

Thanks guys, I'm going to try new spark plugs gapped to .8mm

[GT888]

I'm interested in seeing what happens. I have spitfire coils and gapped my plugs to 0.8mm as almost everyone recommends and it run absolutely crap after 4,000 rpm, gapped them to 1.1 and revs out to redline beautifully.

[Niksmo]

I'm interested in seeing what happens. I have spitfire coils and gapped my plugs to 0.8mm as almost everyone recommends and it run absolutely crap after 4,000 rpm, gapped them to 1.1 and revs out to redline beautifully.

i installed my splitfires today along with new plugs gapped to 0.8mm, idle's fine but when i go to drive my car is missfires hardcore even at low revs...! rkn i should regap to atleased 1mm?

[da spike]

Another question... how do you guys gap the plugs without fooking them? Just tap them down with a small hammer?

[Lithium]

Another question... how do you guys gap the plugs without fooking them? Just tap them down with a small hammer?

I just gave it kinda firm knocks on my workbench and a feeler gauge to verify the gap - seemed to do the trick fine.

[da spike]

I'm just thinking could this be RnR? Because i would find it hard to believe that the coilpacks would have shit them selves after a few months use and i have changed the sparkies too when changing coilpacks to irridium ones... The missfire or popping under acceleration usually happens on a really cold night, the car also feels like it has a flat spot from 4500rpm to 6000rpm and then from 6 onwards its fine...

[mad082]

if it is happening more when it is cold then it may be rnr. but remember that the VCT turns off at 4500rpm so you do get a bit of a flat spot there.

to gap the plugs you need a feeler gauge. basically it is a set of small sheets of metal all different sizes.

i personally think iridium spark plugs are a waste of time. the set in my old 33 were shagged after about 20,000kms. i put the ones listed above in and changed them after 10,000kms and they were still fine. they are only a few dollars a plug.

as for there the tip of the plug is and marking it with a pen and trying to align it with the manifold, you may find that doesn't always work, without ending up with either it too loose or way too tight. however it shouldn't really make a difference as the valve will be closed well before the spark plug fires

[da spike]

Ok I got BCPR6ES plugs and threw them in and took the car for a spin just quickly and it looks like its not missfiring anymore... But I will need to drive it more to make sure because sometimes the missfire would be tempremental..

But what it's still doing is running shit from about 4500rpm all the way to 6000rpm and then it kicks in hard. Do you guys think this is rnr?

By the way I'm running standard boost and its going up to about 9-10psi cause its a cold night and exhaust, intercooler.

[da spike]

i personally think iridium spark plugs are a waste of time. the set in my old 33 were shagged after about 20,000kms. i put the ones listed above in and changed them after 10,000kms and they were still fine. they are only a few dollars a plug.

The iridium ones i took out (i put these in about 10,000 kms ago) were pretty fouled up so i guess copper ones are the cheaper alternative...