94 GMC sierra starts and runs fine till it warms up then backfires shuts off and will not start again until it cools off and repeat??? I asked same question but about a 97 was told it was mass airflow

Check vacuum lines leading from tbi to egr.. check egr operation and clean MAF.

Also, check the vac. line running to the maf as well. should come from the back side of the tbi to the maf.

Check the distributor control module,sound,s like it is getting hot and shutting truck off.

Already replaced DCM, ecm, fuel pump,fuelpump relay, coil

And computer has been replaced

Cataltic conveter replaced?

Or Crank sensor?

Catalitic converter isn't clogged and there isn't a crank shaft sensor on this truck so I've been told...is there one and if so where's it located

I reread that you replaced the ECM,check the igniton switch.

OK I will check ignition switch first thing in the morning... Thanks so much T_S_T...and I will keep you posted

When you say ignition switch you are referring to the actual key switch or is there something else called ignition

Yes,the key cylinder,good luck