(its not the starter, or battery)i have a 1991 camaro rs 3.1. about a year ago it flipped out like it jumped time, so i changed the timing chain only to see it was still in time. it had about 210,000 miles at the time and i have not gotten it running again after a new distributor, IAC, MAPS, 2 COMPUTERS, NEW WIRES, PLUGS, 2 DIFFERENT COILS(THE FIRST ONE TESTED OUT BAD) AND A DECENT SEARCH FOR GROUNDED WIRES. o2 sensor is good, fuel pump relay and pump are good, 45 psi of fuel pressure, turns over but only one cylinder fires ever 5 minutes of turning over.. WHAT IS GOING ON?? oh yeah and before i went replacing stuff it actually cranked with ony a replaced coil and cap and rotor. and ran perfectly for one hour then i cut it off and it cranked, and then kinda acting studdery at low rpm but smoothed out then shut it off again and hasnt cranked in 6 months... ?????????????? and i didnt change anything while it was running then not. (and its not my security key crap. i have already had that problem and fixed it.)

 

It might be your ICM (Ignition Control Module) Its located on your distributor under the cap. Its the little peice that has the wires that plug into it from the coil.