I have a '96 Z28 with an LT1. Lately the car has been running rough and has sent a misfire code to the computer numerous times. The last code I got was P0300 Random/Multiple Misfire. The car stumbles and hesitates when in the 1500 to 2000 RPM range. After 2000 it seems fine. I've tried many remedies such as: new plugs and plug wires, injector cleaner, new cap and rotor, new coil wire. I've checked for vacuum leaks and everything seems fine there. I'm at a loss as to what could be causing this. Any help is greatly appreciated.