intank fuel pump...

[rusty ol ranger]

Just making sure a few things before i drop coin on parts...

1- No fuel coming out of supply line out of tank. There is enough fuel in the tank to get sucked up and pushed out, as evendenced by the mouthful of gas i got when sucking on the line.

2- I unplugged high pressure (frame mounted) pump to isolate any noises coming down the frame. I heard NOTHING goin on inside the tank, no buzzing, no nothing. The intank pump should still run with he high pressure unplugged right? Even with the high pressure plugged in i got no fuel from the line.

My mechanic said 175 bucks to do it if i buy parts. So thats what im gonna do. I got to much other shit goin on to tear into this. But im just making sure before i buy parts that im diagnoseing this correctly.

 

[alwaysFlOoReD]

Are you planning on buying a low pressure pump for intank, or high pressure and get rid of the other frame pump? Or get an inline low pressure pump and mount it just outside the tank? Or get the stock intank low pressure pump?
My race truck [4.0l] and my 89 f350 RV [460] both use an inline low pressure pump outside the tank mounted on the frame rail feeding a frame rail high pressure pump.

 

[RonD]

Yes, you are correct, lift pump in the tank isn't working

The wire from the inertia switch runs out and near the high pressure pump in the frame rail, thats where Ford Spliced into that wire to get 12v to the high pressure pump, then that wire continues on to the top of gas tank for the lift pump

This splice was a known failure point, so locate it by following the high pressure pump 12v wire, should be very close to it

Also the lift pump used a different ground than the high pressure pump, the fuel level sender and in tank pump have different ground wires BUT, they were both connected to the same ground point, so if fuel gauge works the ground is probably OK, but if gauge is not working then..............


EDIT:
The in tank high pressure pumps may have the wrong fuel level sender, Ford changed the gauges and sender in 1989 so you have to watch that, so don't change sender just the pump

 

[fastpakr]

Definitely make sure it's not just a wiring issue, as RonD suggested.

 

[rusty ol ranger]

I had checked that splice before when i was screwin with the hi-po pump. Ill check it again but it was fine before.

The gauge does work.

@alwaysFlOoReD im just gonna replace the factory pump and call it good. It also needs a tank.

 

[fastpakr]

Check with a meter to ensure you're getting power to it.

 

[adsm08]

Check with a meter to ensure you're getting power to it.

That's a negative Ghost Rider. Don't use a meter, hook a headlight to it. That will load test the circuit with something that is similar in load to the pump itself. A meter without a load tester in it can show 12V when there are still wiring problems that keep power from getting through. If it lights a head light it will run a fuel pump. Plug it is hard to see the priming pulse on the meter from the driver's seat. It's pretty easy to see a headlight light off.

Voltage drops across the highest load in the circuit. If you have a bad spot in a wire that might be a higher load than the fuel pump is, but unplugging the pump makes the now open circuit at the connector the highest load, so you still see the voltage. Think about plumbing again. If you have a 1/4 inch pipe that is partially plugged and has a spot that is only open 3/32" and you put a pressure gauge at your tap, you will see good pressure, but if you open the tap you won't get good flow.

 

[fastpakr]

Fair enough. The point is to -test- rather than assume the pump is faulty.

 

[adsm08]

Fair enough. The point is to -test- rather than assume the pump is faulty.

Very true. Always test, never assume, sometimes punt.

 

[Paulos]

Rusty, just pull the bed off, or back far enough to access the tank. Six bed bolts, three screws at the gas cap/filler neck, and the electrical connector at the tail lights. Then the top of the tank is wide open to work on. I've never dropped a tank on a Ranger, it's just too easy to remove the bed.

 

[rusty ol ranger]

Rusty, just pull the bed off, or back far enough to access the tank. Six bed bolts, three screws at the gas cap/filler neck, and the electrical connector at the tail lights. Then the top of the tank is wide open to work on. I've never dropped a tank on a Ranger, it's just too easy to remove the bed.

The tank is junk to lol.

How do i hook a headlight to it?