Arrgghh Impossible Misfire Problem :( Pls Help!

[R31Nismoid]

well one plug is obviously the cyclinder thats causing the problem

To begin, stop using iridi's. They are a pointless waste of money.

as 3lit said - BCPR6ES-11's.

Get a set and put them in and then see how that goes.

Then it will most likely kill the plug again, but thats the problem, the bung plug which looks a tad oily

[ApacheX]

i have just changed my spark plugs today to bcpr6es's and i seem to be having pretty much the same problem. ill have to check my plugs also, but it would be interesting to see what the problem is

[Konrad]

Ok so i disconnected each coil to narrow it down to a cylinder that was the problem, its no.1.

First thing i did was pull the sparkplug out, looks a bit black, and has that shiney coat i mentioned earlier? Could be fuel??? but had no strong fuel smell to it...

Ran a compression test - 150psi on that cylinder (didn't have time to do the others)

Put in a copper plug, didn't fix it, took out the splitfire coil and replaced it with my standard one, didn't fix it.

So at this stage i'm assuming it has to be a wiring fault to the no.1 coil.

[Konrad]

Ok so thought i was stupid to do the compression on only 1 cyl so went back and did the whole thing

No1 150psi

No2 150psi

No3 140psi

No4 140psi

No5 145psi

No6 140psi

no 1 actually gave a reading as high as 160psi but with a couple of repeats the figure was 150psi.

[R31Nismoid]

you disconnected the coil and the idle changed?

If so, its the coil, or a connection to it which might be corroded

Get a spare coil, and test it. If the idle is fine then new pack time.

[HOT_R33]

I had a similar problem to this with my R33. Mis-fired all over the place. Trackside performance found that, when they opened up the loom, half the wiring was corroded! looked like water damage.

When they replaced it, she ran smoother than it ever did before.

So give your wiring loom a check just to make sure its in good nick.

After all, these cars aren't exactly spring chickens remember. A lot of them sit in the USS auction yards for years, outside in the rain and sun. Its gotta take its toll on something sooner or later.

[Konrad]

Yeah was suspecting the loom but the fault was traced to the injector - although there was power going to it, the ecu triggers the injector to inject by earthing it - which it wasn't doing- pulled out the ecu to check for faulty parts, water damage etc- all good- put it back in the car ran fine again! I suspect a loose connection either in the pin of no.1 injector earth lead (on the ecu side) or a problem within the ecu itself- maybe dry solder joint?

Either way problem was fixed and only cost $88 (took it to an auto electrician in the end) !! (i was thinking hundreds at least!!)

[morgz r33]

hey dude im having the excact same problem but im not much of a diy ( still learning) so wat is it i should tell my mechanic to look at? sorry bout stupid question ( noob )

cheers

[ApacheX]

i found mine to be an easy fix, i just took out my plugs and put em back, and rechecked everything was plugged in