I'm kinda stumped. Problem was it was acting like no fuel or not enough. It would idle rough and would stall when stopping. Fuel pressure was low, I replaced the fuel pump (complete) the tank vents fuel tank (rusted, (didn"t want to take a chance), fuel injectors , fuel regulator, 02 sensor and temperature sensor. Every time I replaced something it runs good for a couple of days (smooth as silk) it goes back to pulsating. No vacum leaks and the las thing I changed was the temp sensor, it rough idled and when I disconnected the temp sensor the idle raced so I put in a new one and it was fine for a few days and then it went back to a crazy idle. I also replaced the distributor cap and the ICM and other components attached to the carb. Any help out there I would appreciated. Next is the CPU or Cat.

 

You didn't list it but did you replace the fuel filter after changing the pump ?
Did you use a GM sensor, aftermarket ones are junk.

 

new fuel filter with new tank and pump. All is GM / A/C parts except for the temp sensor

 

If it ran OK for a few days after replacing the temp sensor then acted up I would suspect that sensor went bad. Use the AC one.

 

After the fuel pump was changed it ran fine for a couple of day, then it acted up, after the fuel injectors and regulator it ran good for a couple of days. The o2 sensor same thing and the temp sensor, same thing. I just replaced the fuel pump relay and it seems fine but haven’t driven it yet. Very strange. I am using ac deco but the parts are from China. Go figure.