My car is an 87 trans am with a 305 tpi auto, long story short, car died while backing up. It would crank but not start, I checked fuel pressure(at 40) and tried starting with starting fluid. So I went through the service manuals diagnostic check of the hei system. That turned up a bad ign module. Replaced ign module and the car started but runs rough, hesitation, misfire, backfire and gave a code 42. Again replace ign module from another working car with same result. Once in awhile it will start and run fine till I move the gear selector (rpm drop) then the rough running resumes.

The tps is operating correctly, checked cir 424(by-pass) for opens, connections look good. My concerns are that the dis cap is only tightened on one side, old dis cap bolt broke. Also the old rotor has the little numbs on the inside top wore down(see pic), I replaced this with a new one with the same result from just a couple of startups.

Any thoughts are much appreciated.