93 GMC Vandura fuel pump problems

[Andy54]

I have a 93 GMC Vandura 5.7L. After replacing a bad MAP sensor, I had fault codes indicating EGR and or the EGR control selonoid, Baro sensor ( my van doesn't have one) and a lean exhaust reading from the O2 sensor. I replaced those components, and the engine was still not abel to run above an idle, (she would buck and stall). Now, after it stalled in my garage, I find there is no fuel coming from the injectors. I found the fuel pump was not running when I turned on the ignition. So I checked the fuel pump fuse and it was OK. I then pulled the fuel pump relay and checked it's operation. Everything seemed OK there too. Now I'm trying to check the fuel pump wiring. There are 3 wires leading to the fuel tank, purple, grey, and black. I assume black is ground, but I don't know which is for the fuel pump, and the sending unit. Anybody know which is for which? Also, I tried the old broomhandle trick banging on the tank when the ignition switch is turned on to see if I can get the fuel pump to start working, but no dice. Any help would greatly be appreciated. Andy54

[mrrob]

I see many no starts on these vans cause by the fuel pump, a quick test I would do but be careful, open the fuel line at the throttle body and give it a quick crank, if you have fuel, obviously fuel pump is not your problem.

Good Luck.

Mr.Rob

[JusGene]

My 97 Chev 3500 Van 5.7L was frougth with lots of irregular and seemingly unrelated problems. 99% cleared up when I replaced my fuel pump (which had 58 psi instead of the normal 60-62 psi)

Go figure.

Also, buy a repair manual (Chiltons, whatever). Worth the investment.

Odd chance there is a regulator problem, or other fuel impediment, but I'd have the F/P psi checked, or just replace it. My error codes were on, then off, then on again after cleared for a day. I probably replaced o2 sensors for nothing, except I plan to run it for 100 to 200 thou miles.

Good luck,

Gene