92 chevy caprice

It could be a few thing but first I eould look at the TPS, throttle position sensor. You could have a old rubber fuel line that is collapsing or a bad module on the tranny.

Rebuilt trans in 2014 rebuilt 4.3 v6 3/2017 car was idling rough abd boggin. Took to mechanic who did adjustments on idle .told me i n=d to change tps,iac valve,map sensor. I changed map, iac. Idle is not so rough still have to warm car up with acceleration to avoid backfire. Previous engine(same type) had blow gasket on freeway old engine have valveseal leak would kick up blue smoke after startup.im thinkng i should change cat,o2,tps,iat . Any advice? No codes popped up on diagnosis with jumper on obd1 port(a to b)

Did you figure this out? Same for my 92.