5.9 running fine, started running ruff, backfired, died, waited 5 mins, cranked and ran great for a mile, then died wont start

Just found the mystery of backfure/timing issues on the 90's dodge 5.2 5.9 3.whatever motors, my 94 Dakota with a 5.2 engine, has been giving me problems with timing and backfiring issues for the past 3 years, I've replaced the fuel pump the fuel filter the injectors the ecu, plugs wires distributor assy and distributor gear, crank map 02 and many other sensors, coil, battery, alternatir, checked every relay and connection on wire harness, cleaned thrittle body and replaced intake gaskets belly pan and checked egr+vacuum lines even got cooler plugs installed plus new water pump radiator and thermostat plus fan clutch! All this and the damn truck would still backfire under slight load, so I figured the ecu is a learning computer and was f*cking the timing somehow, this is how i FIXED it... I started the engine, unplugged map sensor,drove around the block keeping my foot on the gas so as to keep it running, parked it with motor still running, plugged map sensor back in, and bam! Runs perfect, and stronger than ever! Im not sure how that stupid stunt worked but mabey the ecu needed a lesson!