Periodic Misfire

[widebody180]

I'm trying to sort out an ongoing misfire problem. It is intermittent, I haven't been able to work out any real pattern to it. I have so far replaced sparkplugs, coilpacks and the coilpack loom with no luck. The only extra clue I've got is that one of my sparkplus was a bit white. Looks like that cylinder might be running a bit lean. I'm thinking maybe that fuel injector is clogged. Does this sound right? Car is R32 GTR.

Edited May 6, 2010 by widebody180

[rob82]

I'm trying to sort out an ongoing misfire problem. It is intermittent, I haven't been able to work out any real pattern to it. I have so far replaced sparkplugs, coilpacks and the coilpack loom with no luck. The only extra clue I've got is that one of my sparkplus was a bit white. Looks like that cylinder might be running a bit lean. I'm thinking maybe that fuel injector is clogged. Does this sound right? Car is R32 GTR.

Does it missfire under load, light thorttle or idle?

[widebody180]

When it starts it happens through all three of them. It just comes and goes occassionally. Lasts for a few minutes at a time. When I'm sitting at idle it shakes the whole car.

[Galois]

have u run the diagnostics?

diy: http://www.skylinesaustralia.com/forums/Re...de-t266512.html

does it make a wrx-y popping sound?

[widebody180]

Yeah error codes showed nothing, came back 55. It does make a bit of a popping sound.

[widebody180]

Think I must have reset the fault codes before I checked it last time because I just took it for a drive until it started missing again and then pulled over and checked the fault codes again. Got a 21, ignition circuit. So with that in mind and the fact that I've replaced coilpacks and loom what's next to look at?

[Crans]

igniter?

[widebody180]

igniter?

Is the igniter the same thing as the ignition amp?

[rob82]

Is the igniter the same thing as the ignition amp?

Yes

[widebody180]

I pulled the ignition amp out today and tested it with my dvom. I'm not really sure what it is supposed to read normally, but testing the resistance across the amp showed some unexpected results.

Bear with me as I try to explain it.

When I connect wires 1-6 on one side with any of the wires 1-6 on the other, there is a circuit. There is quite a bit of resistance but it still makes a circuit. When connected with the earth, there is almost no resistance. The exception is wire 4. When wire 4 is connected to any other, the resistance is twice the reading on the other wires and when wire 4 connected to the earth wire, the resistance is off the chart.

So obviously the connection to wire 4 is stuffed. But should all the wires have a circuit with all others? Doesn't seem right either.

[Pal]

igniter reading are noted in this document

http://www.skyline.se/dokument/R33_All_Engine_Manual.pdf