Won't start

I have a 1995 chevy with a new 4.3 in it. I cannot get it to start, the fuel pump is not coming on. I have changed my oil pressure switch, 3 fuel pumps, and my relay. I have also checked my circuit, it seems to be ok. Is there any other possibilitys that I am missing. It will start and run until i kill it. the the pump will not come on again for a while. then it will start right up. After i stop cranking i can hear the fuel pump buzz then. Whats my problem, any suggestions.

If the relay is getting ground and power when u start up the truck and the rest of the circuit is fine u may want to try a different pcm computer. I'm working with the same problem -- but I think my problem is a grounding problem I have to run some more tests today.

Hello,

You may want to take a look at the fule pump ground wire. After you remove the fule pump from the tank, take a look at the wire that attacheds to the pump it's self. It has a small plastic cover on it. If it is melted than that may be the problem. You can also attach a fuel presure gauge and chech the fule pressure in the system once you turn your key to the start position. Then try and start the engine and record the readings. Sut the engine off and see if the system holds any pressure at all.