'91 5.7l TBI random interval misfire

[Breakdown]

Pull the ignition module and have it tested if you haven't already. Your problem is sounding like what I went through

 

[Lowmiler]

Update to this thread. I replace the plugs and plug wires. All AC delco. Did not get rid of the misfire. Still helped as the plugs that I replaced were whooped.

Replaced the coil and ignition control module today. Both AC Delco. Coil was OE as it still had the original brackets. Anyway, problem solved!!! No more misfire or stumble at idle.

Replacing the coil and ICM was very easy. Drivers side bank back spark plug, not so easy. I have headers and the flange is very thick.

Runs great now. Love the second gear scratches.