What Triggers the spark?
Where do the coil packs get thier signal from to ignite the spark plugs?

I am stillll baffled by my #4 misfire.. Doesn't the cam position sensor trigger the computer to fire the cylinders?

--Scott

Scott are u sure u have the Cam gear matched dead on????? only thing i can think of that would make it keep missing like that.

Well, the computer sends out the signal. It reads position from the crank position sensor for spark advance. It uses the cam position to reference when in the cycle the motor is. This way it can't be firing 180 degrees off.

Each coil has an individual signal from the ECU.

I just thought of something, and don't remember if we have checked this or not... Have you measured the resistance of the plug wires? I don't remember if they are stock or not.

Gettin in the game a lil late here...did you guys check the compression on #4? Move the injector to another cylinder on the other side of the motor? Check the injector wire? Move the plug/wire/coil to other locations? Just thinkin out loud...

Everything that can be moved, has been moved. I believe Scott has done a compression test as well.

Everything has been done all the wires ohm out the same, swapped coils from left to right, swapped plugs, put in a hotter plug, and i put a new injector in #4.

This only came about after the cam install.. not sure what else to do with it.. It still shows misfiring in HP Tuners too.. It has to be something mechanical..

???????? The lifters are quiet.. I put a longer pushrod in.. runs better, but just that one friggin plug is black. I wonder if a valve seat or something is screwed??