1991 Chevrolet Caprice Fuel regulator?

Question

I have a 1991 Caprice with a 5.0 engine. The car starts great! and idols smooth even in sub 0 weather, however after the car reaches full opp. temp (CLOSED LOOP) and I come to a stop and try to accelerate the engine completely cuts in and out I have ruled out the primary and secondary ignition system as I have replaced it all including all wiring for those systems. I have replaced the main PCM, TPS,MAP,O2. However, the problem persists!I am starting to wonder if it might be my fuel pressure regulator or fuel pump causing this problem. The cut out happens when the engine is put under load only. The catalytic converter is not plugged so I ruled that out. I have noticed that when this cut out happens at a slow accelerate that sometimes I hear a pop or backfire coming from the TBI in the engine compartment that makes me think the problem is in the fuel delivery system. Timing is correct. It seems that the fuel is cutting off and on during the cutout. The fuel filter has been replaced too

Answer 1

I would'nt peg the fuel pressure regulator yet as this will cause other driveability issues (like a hard start,poor running etc) But i do suspect fuel system,You need a fuel pressure gauge attached to see how much pressure the pump is supplying.First i would check,the fuel filter.then pressure test.Sounds like fuel pump, but why keep throwing parts at it?

Answer 2

You need to install a fuel pressure Gage,and run it to outside of car so you can monitor the pressure when the problem occurs.it may be a little time consuming but its the best advsise i can give you at this point.