AU 3 Falcon misfirng only when warm

[JohnnyN]

My 2002 AU3 has developed a fault where it starts to misfire badly, but only when up to running temperature.

I've cleaned the throttle body and the sensor thing in there... next step is probably to replace the coil pack, etc.

Just wondering why it would only do this when warm?

Really bad misfire, too - sounds like an old Russian tractor, and shudders like a crapping dog's tail.

Anything else I should check before the coil pack? I've done that once before and I remember wishing many unpleasant things on the 'designer' who put the damn thing where it is!

Cheers

[russellw]

You are probably on the right track.

[PG2]

Originally Posted by JohnnyN

My 2002 AU3 has developed a fault where it starts to misfire badly, but only when up to running temperature.

I've cleaned the throttle body and the sensor thing in there... next step is probably to replace the coil pack, etc.

Just wondering why it would only do this when warm?

Really bad misfire, too - sounds like an old Russian tractor, and shudders like a crapping dog's tail.

Anything else I should check before the coil pack? I've done that once before and I remember wishing many unpleasant things on the 'designer' who put the damn thing where it is!

Cheers

It will more than likely be your coil pack. As with anything electrical, they don't like heat. Essentially, when your motor gets warm/hot the electronics of the coil pack start playing up.

Get yourself a very long extension bar with a 3/8 drive. It will make the job ten times easier. The last coil pack I did took me about 15 minutes.

[aussiblue]

Also check the knock sensor (mounted on the inlet side of the engine block near number 5 cylinder) has not come loose and has more than 10,000 ohms resistance across it's two terminals. Also check that both the crankshaft position and camshaft position sensors near the harmonic balancer are firmly attached, clean and oil free with and sound wiring harnesses.

[guzzis3]

Yeah I had a similar problem, was the coil. Trust me the coil is easy, try doing the inlet manifold gasket!

I replaced the knock sensor due to an error code, but it was fine. Do check it's tight though.