1987 Blazer Fuel Problem
After off-roading, my 1987 Blazer quit and wouldn't start. Turns out the fuel pump isn't operating. If I bypass the fuel pump relay and feed 12V directly to the fuel pump it works fine, but when I connect it back up to the fuel pump relay - no dice.
When I turn the ignition on, the fuel pump relay pulls in, sends 12V to the fuel pump, and then after about a half second turns off. I'm guessing that the engine control module is sensing some sort of fault and disabling the fuel pump.
I know that there's a low oil pressure sensor than can cause the engine control module to turn off the fuel pump - but I think this is only in the running mode.
Anybody got an idea of what else can cause the engine control module to disable the fuel pump?