frustrated beyond belief, please help

[MrShorty]

Okay, if i find where the ground is located, where do i go from there? like do i connect the new ground to the bolt that the original ground is on? or do i splice into the wire and run the new wire off that? oooor do i re-route the wire and connect it somewhere else? and does it matter what gauge wire i use for the new wire?

Depends on what you are trying to accomplish with the test. Usual first test for the ground wire would be to disconnect the fuel pump connector at the tank (on mine the connector was above the axle tucked up in the frame rail. Then set your multimeter to ohms (lowest range) and measure the resistance through the ground wire to the frame. Resistance of the ground wire should be essentially 0 ohms. If the resistance is essentially 0, then the ground wire should be good. If there is a significant resistance, then the ground wire has a problem.
If you are looking to splice in a temporary ground as a test, again, I'd probably splice it in near that tank connector.

 

[tweakedlogic]

This is what I would do since it starts with ether and has no fuel pressure at the rails.

Either use a spare battery, or make long 12 gauge or larger "jumper" wires run from your fuel pump to the battery. Make sure you hear the pump turn on. When you verify the pump is running, turn the key to start the truck. If it runs fine, you have no clogs in the lines or rail. That means you have an electrical problem.

BTW, it's easier to access the fuel pump if you cut a hole under the rear passenger seat, then make a plate larger than the hole to go over it. seal it with RTV and self tapping screws.

Back to testing...
I don't have my manual handy, so I can't tell you which wires are what. Use your multi meter to test the ground from the wire harness clip. You can use the Ohm setting, but there may be a continuity setting. This is easy because it will sound a buzzer when it sees a connection. Not necessarily a good connection, just a connection. If using Ohms, you should have a known good ground @ your multimeter. Clean metal! you should have low resistance for your fuel pump ground wire.
If you have a bad ground or no ground, make one. It's easy, use a but connector with heat shrink tubing on it, splice into the ground wire from the harness clip, connect your new ground wire and ground it to a known good ground with clean bare metal with an eye connector, star washer, and self tapping screw. Paint over the connection to prevent rust.

After you hve verified you ground is good and still not turning on the pump, have someone turn the key while you test for 12 volts @ the harness connector. If you have no power @ the connector, you need to work your way up to the front. Follow the harness as far as you can to make sure there is no breaks or damage. if so, fix it and test again. It's a good idea to test your fuses with a multi meter.

(side story) My tail lights went out on a trip recently, I looked at all the fuzes and didn't see any bad one. Using a multimeter, I tested both poles of every fuze and found one that looked good, but wouldn't pass current. I replaced it and everything works.

Back on topic. Test both poles of every fuze with the key on. If one side has power and the other doesn't, replace it. Don't forget under the hood. Also, be sure and test all of your relays. They can fail. Found this video. http://www.youtube.com/watch?v=3JB63ebFfgU

Keep at it. You know it runs, We'll get it.

 

[PeteK123]

Since you replaced the fuel pump, did you bleed the air out of the system ? When you open the system you need to bleed the air out of it. You have an air bubble in the system.

Turn on the key, fuel pump pressure goes up, let air out from shrader valve by using fuel pressure gage, or by just pushing it in til air bubbles stop comming out. Then try it, it will start once most or all of the air is out.

 

[GunnerSchenck]

okay so its been forever since any of these posts but just wanted to say that it's still not running. after posting these, i felt i needed some time away from the thing but now im back at it. just wanted to update the situation. replaced the relay and all fuses(felt like i might as well), but then after about a month without trying to start it i removed the fuel line going into the fuel rail and there was still fuel at the end of the line that came out when i undid the line, which made me think that perhaps the fuel was never getting into the rail or something? so i removed the rail and injectors and cleaned the rail and got new injectors but it still doesn't start. i feel that now it must be electrical...D: what ive feared all along. and therefore, since i don't feel too comfortable with electrical i'm getting back on this site in hope of guidance. any ideas where to start?

 

[MrShorty]

Reviewing the situation, there are two significant observations I see. 1, the pump is running and 2 there is no pressure at the fuel rail. First thing I'd probably do is re-confirm these observations. Assuming these observations are still true, the next 2 things I'd check are:

1) Check the voltage at the pump. If it is significantly less than 12 V, then there's a fault in the fuel pump circuit that could be preventing the pump from running at its full capacity.
2) Check for gas being returned to the tank. 2 ways to possible test this. Find a convenient spot in one of the flexible hoses of the return line and carefully pinch the hose off. If the pressure jumps up, that indicates flow through the return line. If you go this route, be very careful not to damage the hose. Alternatively, disconnect the return line somewhere and run the pump and see if anything is coming out of the return line. If the pressure is low and there is flow through the return line, that indicates that the regulator is stuck open. If there is no flow through the return line and the pressure is low, that indicates some fault at the pump or elsewhere upstream of the regulator preventing the system from building pressure.

 

[Alsorath]

another possibility for you. Had a couple of instaces where the line connecting the actual pump in the tank and the plate at the top of the tank had rotted. pump worked fine, but was only circulating fuel within the tank.

 

[Dano!]

Ruling out your ground.

NOTE: The sending unit shown is one that was modified don't cut your wires in your sending unit.

First pic shows what the plastic bushing on the bottom of your sending unit looks like when its bad / melted. notice how the three on the right are nice and white. the one on the left is warped and destroyed.

The second picture shows what i eventually did to identify my ground as the issue revolving around my fuel problems.

Nothing too crazy. now you know what the plastic bushings look like when they are bad. if your plastic bushing are bad. replace your sending unit. if they are good try the test depicted in the second photo. if it works then one of your issues is solved.

- Dano