I have a 94 5.7 tbi 1/2 ton Silverado.It runs fine for 6 or 7 miles then it will start missing & backfireing through the carb & die.It will start & run as long as you don't give it a lot of gas.Can anyone point me to what might be wrong? I would be really thankful.

 

It sounds like you have either a timing issue or a sensor issue. If the timing is correct the throttle positioning sensor might not be sending the ECM the correct information.