engine misfire

[urasula]

hey all,

what happens when the engine misfires, and how do u know when the engine is misfiring?

[G20-KIWI]

It'll run like a pig, foul plugs, stall, piss you off then maybe get worse.
Check your plugs, leads, dizzy cap, coil, if its a p10 then it could be
the AAC valve, EGR valve, Throttle position sensor or maybe the
Mass air sensor ground as many people have said. If you read the
maintenance threads you'll probably find heaps of info.

[P10DET]

Originally posted by urasula
hey all,

what happens when the engine misfires, and how do u know when the engine is misfiring?

Basically, it's an extreme incomplete burn of the mixture in the cylinder.

A misfire occures when fuel delivery is so bad or incorrect that the spark plug cannot burn the mixture completely. It also occurs (probably more commonly) when the electrical system is unable to fire the spark plug with enough power to burn the mixture completely. Or some combination of the above.

Sometimes you will experience a low rpm misfire. Sometimes it's high rpm. Sometimes in the middle (though less common), or sometimes all throughout the rev range.

It manifests itself as a "stumble" usually. Sometimes you can get through it by either applying light throttle or sometimes full throttle.

It's impossible to cover all types of misfire and what can be done about it, if anything.