Help Me Fix This Misfire...

[notmad]

I have a 1998 25GT R34. Non turbo.

I bought it about January last year. Every few months, the engine misfires HARD. Even when idling. I'd turn it on one day then it'd just shake and sputter, leave it, try again the next day and it'd be fine. Then a few months later it'd do it again. Took it to the mechanic but as soon as it gets there it literally stops misfiring.

About 2 months ago, I finally had enough of it and took it to the mechanic. Once I got there it fixed itself. So then he suggested replacing the spark plugs. So he replaced them and it's still misfiring. So he used the tester and got the error IGNITION PRIMARY 43 or something, which he reckoned was the coils. Suggested I take it down to the autoelectrician, then he did the same test. Got error 43. So apparently one of my coils was stuffed because the misfiring was getting unbearable. So he reckoned it was the coils. Replaced it, then it stopped misfiring.

Had been sweet for a month or so since he did it, but occasionally it misfires like it did when I first got it. Seriously does anyone know what the problem is? Feels like a big waste of money keeping on taking it down to the mechanic but it being sweet once I get there then he can't find the problem. It was misfiring on the way to uni today so that's what inspired me to make an account and ask.

Appreciate any replies. Thanks. Just ask if you need more info.

[Stock e-Tune]

might be an idea to replace the other coils in the set.

As you're a student then buy 2 coils and replace/swap them over two at a time.

making sure to leave the new ones in long enough to be sure the fault has gone..

[notmad]

As i'm a student i can't really afford to replace the other coils. It was hard enough saving to replace all the plugs and that single coil. Might just sell it I think.

Howcome you think I should replace the others? When the first one stuffed out, the engine check light was on but since replacing it, the light hasn't been on and the diagnostic machine didn't come up with anything.

[SargeRX8]

The misfire is caused to due loss of spark, its either somewhere in the wiring, somewhere in the coils, or somewhere in the spark plugs. Its silly to replace one, because when one fails, they all start to follow.