1993 Oldsmobile 98 Engine backfires and lacks power on acce

I have a 93 olds 98, 3.8L engine. Approx 167,000 miles. The car seems to run fine during idle, but upon acceleration, it is sluggish and runs as if it is missing a spark plug. If I push the gas pedal about 1/2 way down, it backfires (almost constantly), and is very sluggish, with almost no power, especially on an incline. I have to press the gas pedal completely to keep it from backfiring and to get any power out of it, and even then, it runs as if it is misfiring.

I have spark on all of the coil packs. I had NAPA check the ignition module, and they said it tests fine. They tested it twice in case it failed upon heating up, but it tests fine.

I have replaced the plugs and put on different plug wires (not new ones, but ones from another car that runs fine)

I have removed and cleaned the air flow sensor.

I have tried to jump the OBD connector to get at the codes (I don't have access to a pre-96 code reader), but could not get warning light to blink as if it was working.

Any help would be greatly appreciated.