I swapped a complete 94 tbi 350 and nv4500 from my daily driver when it was totaled into a 1973 k5 blazer. I replaced the chassis harness and added a painless tbi harness. After install engine fired right up and seems to idle fine. Now the but if I rev the engine it starts backfiring missing and dies or if I put it in gear and try to take off I get a loud backfire and engine dies. I replaced plugs wires cap rotor and distributor. No change in performance.
I was told to place a 3.9k ohm resistor in the adl to see if it was a mechanical or electrical problem and with the resistor In place the engine revs all the way up and I can drive the blazer with no problems.
So now I have no clue what sensor or electrical problem I have.
Currently useing ECM 16196396 azds as that was the one from the vehicle the combo came from also have a 1227747 and have tried that ECM and the same symptoms persist and the resistor seems to fix the prob