I have an 87 2.8 blazer which started popping like it was backfiring. At first it was just under load (up hill) then it started doing it all the time. Very sluggish and rough idle. It has new plugs and wires, new throttle position sensor fuel pump and filter. Have not had it coded on anything. Yesterday I changed the coil pack and it ran the same on know my way to work( about 40 miles) then on my way home it ran great until half way home. Started doing the same thing again. Once I got home I run to town and then it happens, it dies! I try to start it and it just turns and turns. I have to hold the gas pedal down to get it cranked and rev it up to keep it running, once I stop it dies. So I got it home, finally after shifting from neutral to drive and revving the motor the whole way. Once home I looked under the hood and smoke was coming out of the throttle body, I think out of the tps. It is also blowing back up through the throttle body. I can see gas around the whole thing. Any help would be appreciated.