I have a 2000 ford f150 here with a Triton v8 and a non operational fuel pump. It sat for 5 or 6 years and the local rodents tore into the wiring harness underneath the front driver side wheel well. I have patched the harness well, but there is still no power reaching the pump whatsoever. I have checked the 30 amp fuse underneath the dash, and have also check the inertia switch. I don't know how to check the relay but the fuse is good and the relay is in place. The fuel pump was replaced shortly before it sat. It is also worthy to mention that the brake lights, turn signals, and reverse lights all work. Not sure where to go from here. After looking at the other posts here and elsewhere, I checked for a Theft light and see no such thing. There are also two wires that have been chewed through on the passenger side that come out of the ECU wire block. (They're colored a yellow/white with a green stripe and another with a red stripe.) One recieves continuity but I do not know where to reconnect them. Any help would be much obliged.

 

Does the vehicle crank? Have you checked for pressure at the fuel rail? It sat for 6 years? The gas in there is probably concrete at this point

 

The vehicle does crank and starts when fuel is poured down the intake at the throttle body. New fuel has been put in the tank and it reads on the instrument cluster to be a little over a quarter full. There is no pressure at either the fuel rail or the fuel filter. I have identified a pink and black wire that should be the main power to the fuel pump.

 

Have you checked for power at the pump. Did you drain the fuel lines and clean them out? 5 years is a ling time for gas to sit. I would venture to guess any that was left in there is essentially concrete @ this point.

 

the gas in the lines is still liquid. There was no voltage at the pump but after hours of tracing I found out the problem. Even after the voltage was reaching the pump no pressure was made in the lines. Going to blow them out tomorrow and change the fuel filter. Hoping the lines aren't clogged.

 

Can you hear the pump run when you turn the key on? If there's voltage at the pump and it's not running, the pump is bad.

 

I dont hear the pump running, no. But it's also only getting around 1 volt most of the time. The fuel pump relay is getting right under twelve on two pins and between 0 and 6 on the third. The fourth being a ground. I'm getting a new filter and a new pump tomorrow. I'll let you guys know.

 

It needs a lot more than 1 volt.

 

I read somewhere that it only primes with 6 volts and then receives more when it seems to need it.

 

The fuel pump is powered through a 20 amp fuse to the pump relay contacts. The pump relay is opersted separately by the PCM and has no direct control of the voltage.
From the relay to the Inertia switch contacts, then back to the Pump and ground.
There is no voltage dropping or regulator control in the circuit for pressure control.
Low voltage has to be one or more of the following;
Low battery voltage,
Fuse fault or seating,
Pump relay contacts,
Inertia switch contacts,
Pump plugup,
wire harness fault, or poor ground.
.
A very simple series control circuit.
If the voltage measures low, there is high series resistance the voltage is being dropped 'across'.
Voltage depends on how it is measured. With the pump circuit completed and power applied, a high resistance will show lower voltage, (a fault).
Tested open circuit with no pump load should measure full battery voltage. If low, there is nearly an (open circuit) at some point.
Don't forget a poor ground if the above test are ok. The ground is needed to complete the circuit back to battery negative. Check this behind the drivers side kick panel.
None of this is rocket science.
Good luck.

 

All is well in the world. Fuel pump turned out to be dead and as well as jimbo said, the gas in the lines was still garbage and there was a major plug. New fuel filter and pump installed, I'll be replacing the fuel filter again after it drives for a little while. I put pressure through the system through the Schrader valve on the fuel rails and blew out what seemed to be a plug judging by the noise it made. Despite voltage issues we have major fuel pressure now. However, I am now led to believe that the injectors are clogged and need a good cleaning because the truck still won't start. (Verified to have spark and air and fuel pressure, just no real fuel delivery.) Thank you for your replies and I apologize for my lack of useful info in my posts. Thank you guys.

 

This situation has repeated many times over the years where a truck has set for long period.
Tank drained, lines and fuel rail blown out and filter change is the normal routine but many still fight it to the same end result.
Good luck.

 

You can use noid lights to see if the injectors are firing or not. Some parts stores have them in their loaner tools, otherwise they aren't expensive. I'd do that before pulling the injectors.

https://www.autozone.com/test-scan-a...ece/948078_0_0

 

sorry y'all, it's me again. Fuel pressure is great, injectors are cleaned and firing perfectly, however I'm not getting any spark. The engine sounds like it's trying to fire but it's not actually cranking over and starting. I have some knock sensor wiring that isn't connected and I can't find the connections for them. Any help would be greatly appreciated. If anybody else has a 5.4 liter in their truck and wouldn't mind showing me a picture of where the wires come from that would be very very helpful. (YELLOW WITH RED STRIPE AND YELLOW WITH BLACK STRIPE OFF THE PCM HAVE BEEN CHEWED THROUGH)

 

I don't know if your confused!
Cranking and starting are two different actions.
Is the motor cranking? yes or no.
If yes, address starting first.
The knock sensor has nothing to do with starting. Get that addressed later.
Spark, how did you determine no spark?.
Power for both the injectors and coils come from the same fused source.
If the injectors are bring pulsed it indicates the Crank sensor is working so the motor must be cranking over to accomplish that.
If the harness is open or not plugged up, the coils cannot be pulsed.
Be sure you have about 35 psi at the fuel rail test port during cranking.
Good luck.