miss fire

[jrpiecemind]

i have a 95 jimmy 4.3 W installed new cam sensor, 2 new knock sensors, map sensor, 2 O2 SENSORS, NEW THROTTLE POSITION SENSOR. NEW COIL new plugs, rotor, cap, wires, new spider,new fuel pump and this animal still idles rough and missfires and sets 300 code can anybody help

[BigBlue77]

Have you done a compression test? If so, what did you come up with? You said it is rough at idle, does it smooth out as the RPM's increase?

[Blue Bowtie]

I've had P0300 DTCs generated when three rocker arm studs were pulled off the heads. Obviously, it idled poorly and ran rough.

It's not always a sensor or ignition component. Like BigBlue advised, check the mechanical condition of the engine.

[jrpiecemind]

does anybody know what what the cylinder compression should be on 1995 jimmy 4.3 W with 20.000 miles on it