I have a 1989 IROC with a 5.0 TPI engine. I have replaced the fuel pump with a new Delphi pump because after the car has been driven and gets really warmed up I have a noise coming from the tank. It is doing the same thing with the new pump as with the old one. It sounds like the pump is loading or binding or something. A fuel pressure check while it is making it's riduculous racket showed normal pressure. Sometimes you can smell gas but not always. I have replaced all 8 injectors, checked fuel lines for blockage, replaced filter, replaced fuel tank vent valve and the purge valve on the cannister. Has anyone had this problem and if so please tell me what is going on. The car is possessed!!!

 

I have had a bad AC pump off the shelf.