Ok well the short & Skinny is my truck died at a red light over the weekend. It will still crank it just won't start.

Last night I had someone cycle the key on and off while I was under the truck and I did not hear the fuel pump come on...I am not sure if you can but I know in my Mustang I can hear it in the drivers seat so I would imagine I should have heard it.

Next step, I had the key cycled a few times and even tried to crank it once or twice then I depressed the pin on the schrader valve and no fuel came out.

I did notice that after we tried to crank it there was a gargling like hiss comming from the regulator, if that means anything.

I checked the fuse for the fuel pump and the relay and both are fine.

So suggestions, I was thinking about going to the parts store and getting a code reader and see what that didgs up, next I was thinking about pulling the bed and inspecting the pump itself.

This is the first F-150 I have ever done any work to so you guys input would be appreciated.

 

yes, you should be able to hear the fuel pump from underneath.

Also, what year is your truck? You might not need to buy a codereader (95 and prior you can do with a paperclip)

I'll be it is the fuel pump, though--- it has to be.

 

The truck is a 97 4x2 with the V6 in it. I am thinking it is the fuel pump as well. Someone told me to check for spark, but the chances of that going out all at once with no indication whatsoever are pretty slim to none. I know usually when plugs, wires, coils etc... go bad they usually show some sign of it prior to. Up until it killed it ran like a dream. I guess I will get a fuel pump and pull the bed off this weekend.

 

No need to pull the bed off. The tank drops out easily enough. g luck

 

Well the bed is what 4-6 bolts? I have almost a full tank of gas, so I would have to imagine that pulling the bed would be the easiest way to go here?

However seeing as you guys know more about this than I do let me know if I am thinking this through the right way here....

 

Update:

Well last night I figured I would check the spark since aparently there is no fuel getting to the motor. Well I pull a plug wire and put the tool on it, it didn't light up so I was sure there was no spark either. not wanting to trust the tool seeing as with my luck there is a possibility of it being bad I tested again. I took a screwdriver and stuck it into the boot, then I tricked my little brother into holding the metal part of the screwdriver while I tried to crank it. He didn't jump or yell so I have to assume that there is no spark either.

So what on earth could make both the fuel and spark go out at the same time?

I noticed on the firewall there are two fuses that say Primary battery fuse. I still have all electrical functions of the car, just no fuel pump and no ignition.

I am clueless at this point. A friend of mine is a GM tech and is bringing over a fuel pressure gauge and a coil tester tonight so I guess after that I will know for sure that they are both not working.

 

Well another plea for help I guess. Well there is officially no spark and no fuel.

I pulled the harness off of the coil pack and it does have power, well atleast one wire had power as verified with a test light.

Just to make sure I also checked he inertia switch and it is ok.

I bought a universal OBD codereader and it won't pick up anything it just shows an E which I have to assume means error. The users manual said to start the car then plug it in, since I can't start the truck I am figuring maybe that has something to do with why it won't read it and is showing a big E instead of codes.

One thing that did stand out to me. After reading through any thread I could find here about ignition or fuel someone posted something about the check engine light not comming on when the key was turned to the on position. Well I can't remember what it did before but now the check engine light dosen't come on at all. I checked my Mustang and if I turn the key to the on position without starting it the Check engine light stays on until you start the car.

I am grabbing at straws here but is there anything on this truck that would disable either the fuel or spark if there is a problem with the other. Maybe disabling the fuel system if the ignition goes out to keep from flooding the motor?

I am tempted to just install a new fuel pump and change the fuel filter so I can atleast eliminate that aspect of it and work on the electrical end.

About the only other thing I can think of that would cause both to go out at the same time is the PCM. Anyone know if there is a test that I could see if this is the problem?


Any hel would be great -Jeremy-

 

Is your instrument panel working. Have you checked fuses #30 and #24.

Fuse #30 in the passenger compartment fuse box energizes the PCM power relay and fuse #24 in the power distribution box supplys power thru the PCM power relay to the COP's and energizes the Fuel pump relay.

 

I know I checked every fuse that had anything to do with fuel and or PCM functions but to be on the safe side I will check them again tommorrow after work. That would be great if all it is is a damn fuse....well I would look like an idiot but as long as it works right

 

Did you use an ohm meter to test them, or just visually inspect them. If you used a ohm meter then maybe its a wire instead of a fuse problem. Anyway it could not hurt to check them before spending money on a fuel pump.

If your good with tools then you could build a special test plug by cutting the plastic top off the the fuse with a hack saw so that you can attach alligator clips on it and see if you measure any voltage across it when you try to start the engine. Just cut the plastic around the terminals, not the terminals themselves. Then cut the fuse part between the terminals so that you can measure the voltage. If you dont get voltage across this test plug on each fuse when you start the vehicle then you have an open circuit.

If the fuses test ok and you see voltage across fuse #30 (using the test plug in place of the fuse) but you don't see voltage across fuse #24 (using the test plug in place of the fuse) then the PCM power relay is suspect and should be tested.

If you see voltage across both the #24 and the #30 fuse (using the test plug in place of the fuse) then the pcm power relay is suspect and should be tested.

I have a digital volt/ohm meter so it will read either -12 or +12 volts so I don't have to reverse leads when testing.

I also recommend a fuse puller tool (plastic) rather than using pliers to get the fuses out.





Good luck and be sure to post results here for the benefit of future posters.