My truck recently quit running on me, while I was driving no less. It seems that it isn't getting fuel. The fuel filter was changed a few months ago, so that shouldn't be an issue. I changed the fuel pump today, but still no luck. I took the supply line off of the fuel filter, and tried cranking the engine to see if any fuel came out. None came out at all. I have checked the fuel cut off switch, the fuel pump relay and fuse, all seem to be good. Any suggestions would be greatly appreciated.

 

Have you ever used the fuel cutoff switch before? You have to put a tiny flathead driver in the slit to release it. Maybe, if you're lucky, the button is just down. I'm curious what else it could be.

 

Right, the inertia breaker reset.

 

Also check all the wiring going to the fuel pump, as a critter may have decided that it was tasty.

 

Sigh...

Okay, there's how it actually works.

1. The PCM has to be powered up and operating so it can turn on the fuel pump relay which runs the fuel pump. If the PCM doesn't power up, the truck will never run.

2. Quick check to see if the PCM powers up: Watch the MIL when you first turn on the ignition switch. If it lights up, the PCM has power. If it doesn't light up, check the fuses for the PCM and its power relay.

3. Assuming the PCM does power up correctly, it will activate the fuel pump for a very short interval, about two seconds, to pre-pressurize the fuel rail. It will NOT power up the pump again until it detects that the engine has fired during a start-up attempt.

4. LISTEN carefully during that two second interval for the sound of the pump. If you hear it, it's running (although not necessarily doing any work). If you don't hear it, go back and check the inertia switch (just push down on the button and make sure it's locked in place, keep screwdrivers away from it(!!!)).

If you understand how the system works, your odds of logically diagnosing it increase exponentially as compared to "replace and pray, then bitch if it doesn't work".

 

Sigh....