No fuel pressure
Asked by Dave Apr 29, 2018 at 12:10 PM about the 1994 Chevrolet Suburban C2500 RWD
Question type: Maintenance & Repair
Drove in now ...No start ... no
fuel
Changed fuel pump & filter
(new) still no start ... no
sounds from the pump ... will
fire when primed only ... wont
stay running ... reset switch
??? ... 1/2 tank of gas !@!
2 Answers
Is there a fuel injector pulse, engine cranking? Did you use a gage and check fuel pressure, engine cranking? My hearing is no good, I can't hear the fuel pump with engine cranking. I'm starting to wonder if there is an rpm signal? W/o that signal, the computer won't ground the fuel injectors, then no fuel.
The way the fuel system works is that when you turn the ignition switch on but not start the relay will close and energize the fuel pump for about 5 seconds. If the ECM does not see the crank sensor seeing the engine revolving then it shuts off the relay. You should hear some "Buzz" in the tank to indicate the fuel pump is ON. You need to just jumper the fuel pump relay and verify that the fuel pump is not energized along with a fuel gauge just to be sure.