about the missfiring system
 

hi can any one tell me what is a missfiring system is ??

I am not 100% sure. But, I think it has something to do with turbo cars. More specifically, I think it is a way to keep the boost level up while you're off the throttle. I don't remember how it works, I think it dumps fuel into the exhaust manifold then ignites it in there to spool the turbo. I'll go poke around the net, im sick of homework.

that will be cool man

The correct name for this system would be anti-lag system. This system is usually used in rally cars that is equipped with turbos. Balistc does a good job explaining this.

"Anti-lag systems retard the ignition timing so unburned fuel passes through the engine and, instead of igniting in the engine, ignites in the exhaust manifold, and spins the turbo over.

The air needed for this combustion is provided by the standard throttle body, which is opened to a greater extent than normal whilst anti-lag is running...thus the reason it has a solenoid to keep the throttle open

The ECU uses an idle control sequence so that once you've set the target idle speed, the anti-lag will cut a spark in a rotational sequence with each cylinder, which is why they idle so lumpy, and thus the reason its called rotational idle. If there was no rotational idle, the engine wouldnt idle at all, because the throttle is so far open that the engine would just rev.

The theory is, as soon as you open the throttle, you have full boost and no lag" (quoted by Balistc from NASIOC)