4.3 rough idle

after startup engine either dies or idles rough. its gets better after warmup but doesnt go away.engine is 1991 with tbi.engine is new. new parts include tbi,egr,tps,iac,map,temp sensor, plugs,wires,dist,o2,and timings is set at 0 with pigtail unhooked. no codes come up i guess the computer is next unless someone knows different....

after startup engine either dies or idles rough. its gets better after warmup but doesnt go away.engine is 1991 with tbi.engine is new. new parts include tbi,egr,tps,iac,map,temp sensor, plugs,wires,dist,o2,and timings is set at 0 with pigtail unhooked. no codes come up i guess the computer is next unless someone knows different....

I guess first thing is to check the fuel pressure...should be between 9-14 psi..I like to see about 12.
Low fuel pressure...below 9 psi will allow the engine to start but will not be enough fuel pressure to keep the engine running..especially cold.
Also look closely at you vacum lines and check the intake manifold for vacum leaks...including the EGR valve

all new vaccum hoses,new fuel pump and shock screen have 12 psi fuel pressure with no vac. leaks detected. egr-ok. have noticed when you unplug the sensors and restart the engine it seams to idle ok at around 500 rpm,s as soon as you plug the sensors back in the problem returns. even after i reset the computer.

Which sensor are you unpluging?

temp,iac,map,and tps

temp,iac,map,and tps

Disconnect one at a time and see if it changes...you may have a degraded sensor causing your problem.

as i said in my first post all my sensors are new. man im running out of options.