I've replaced all the spark plugs, all the spark plugwires, fuel filter, MAF, replaced the PCM, and the car is still misfiring, i was thinking of changing the injectors next. but i wasnt sure if maybe my PCM just needed a good tune, cuz mine is a 1994 z28, and cant be chipped. all i have done to it is a K&N CAI, 85mm granatelli MAF, magnaflow cat-back exhaust.

P.S.- what all do i need to do to remove the injectors? take off the fuel rail?

 

Before you go on throwing parts at the car you need to do some trouble shooting. Leave the PCM alone, that is probably the most reliable part
1) Using a scan tool check for trouble codes. Active, pending, retained
2)Verify that the new MAF is good and calibrated properly. Disconnect the electrical connector from the MAF & see if the engine still misfires. If the misfire stops the MAF is probably screwed up.
3) Re-check you plug wires, make sure they are going to the right place, not shorting out or burned up by touching the exhaust manifold.
4) Check all ignition components, coil, coil control module, optispark. Pull the connectors & check for corrosion. The Optispark is a major cause of misfires because it controls all timing signals to the PCM and handles high voltage at the same time. However, because of the cost all other possibilities should be investigated
5) Check the fuel pressure and pressure regulator function with a proper gage.
6) with a scan tool, check operation of O2 sensors, verify that the temp sensors ECT & IAT send the proper temp readings to the PCM.

 

i unplugged the MAF today and it still misfires the same with it unplugged, so the MAF is good. i literally got the plugs and wires changed yesterday soi doubt they are the problem,it ran the same after the plugs and wires were put on compared to before they were.i will hook it up to a scan tool at school in a couple days.

 

When i had my Z i thought i was going to have to replace the opti for the second time in 6 months but it was the ignition control module...

 

check all the wires. if they are loose or not connected, they can make the engine misfire and not even turn on. i learned that the hard way.

 

I agree, check all your wires first, and make sure, especially the right side is connecting properly., I was beating myself up with a misfire, Was positive the wires were connecting properly. Then one day I said screw it, took out a multimeter and starting checking continuity because i didnt want to trace all the wires again. Sure as hell I had two wires crossed. Surprisingly enough is that the computer was showing a random multiple misfire, not a cylinder specific. After I switched the wires, I wore a dunce cap the rest of the day, and the car wasnt missing anymore.