Hello all,

2000 6.8 v10 gas Excursion, 134k miles

My finances have been marginal recently and I have been running low on fuel more often than I like. I was quite low, light came on this time, but I was late for a Dr appointment for my wife and pushed it to make it, planning on driving less than a mile afterward to get some gas. What I hadn't bargained for is the parking lot being on quite a grade. I parked nose up, and when I left, it started, sputtered a little and died.

I walked up to the gas station, bought a 2 gallon can and put 2 gallons in the tank. No dice. Walked back, another 2 gallons. Nothing. Walked back, another 2 gallons. Nothing and my battery was dead from trying. Put out a call for help and one friend came with 5 gallons of gas but a new suv he refused to jump my truck with, second friend came and jumped me. About 11 gallons in the tank, no start. Rocked the truck and reset the inertial switch- started, sputtered, died. Poured a little gas into the TB as my friend tried to start it- ran without a problem. Good sign, it's fuel delivery, not electrical. Checked fuel pump fuse, good, swapped relay with another one, no luck.

by this time, we had been in the parking lot for almost 5 hours. Family was tired, I was out of field operable ideas, so I was able to get her towed home.

in the morning, I was thinking the following troubleshooting-

1- remove fuel filter
2- turn on ignition to see if anything pumps out the line- yes, we have a fuel pump, no, we have a dead pump or electrical leading to it.
3a- if fuel pumps out the line, replace filter with new one I have, pop Schrader valve on the fuel rail to clear any air, see if it runs.
3b- if no fuel, blow air back through line to clear in tank sock if it's clogged. Check again. If still no fuel, try to get a hot, clean 12v lead back to the harness for the pump and jumper it, somehow, to bypass the ECU, relay, and fuse system. If still no fuel... cry a little, drink some bourbon and prep to drop the freaking tank.

any other ideas?

Thanks,
Michael

 

This is the fastest and easiest way.

Just go in from the front pass kick panel, remove it and jump the fuel pump wire at the inertia switch. That way you know you are direct with the power to the FP.

If the pump works as it should its electrical, if not, its mechanical.

I would think its a possibility you overheated the old pump by not being immersed in gas.They like to be kept cool.

Also another trick when you are low on cash. Call 1/4 tank empty and put fuel in when you hit that level. That's what I used to do.

Now when it hits 1/2 tank I fill it up. That's my new empty.

Where you at in the US?

 

I will agree, fuel pumps don't appreciate running with no fuel. Likely it gave up after 17 years. Odds are low that an electrical issue would pop up at that exact moment.

The troubleshooting you outlined seems reasonable, though I would skip blowing air back through the line. If the sock is that clogged, it needs to be dealt with. What that might do is move the fuel pump a smidge that will make it run again. Only to strand you again at a worse moment!

 

I agree with the above advice, most likely a dead fuel pump, but do the troubleshooting to be sure. And don't do the air blow back, as Eric said it could give you more trouble. If the pickup sock is clogged, all that trash will just refind the sock again, it's the only way out of the tank.
Aside from the freshly added 11 gallons of gas, dropping the tank really isn't that bad of a job. I would try to empty the tank first, either by using an external pump (I have an old Holley pump that I use) or carefully siphoning it out into cans. I have successfully dropped the tank with the fill/vent tubes fully attached (just taking the 3 mounting screws out inside the fill door) and carefully manipulating it between the cab floor and frame as I lowered the tank on a floor jack. I've also done it by removing the rubber hoses from the fill/vent tubes, for me the first way was easier. The tank itself is only held up by 4 bolts that are easy to get to and the wiring and fuel lines on top of the tank all have enough slack to stay connected until the tank is all the way down. Having a helper or two to keep the big tank balanced on the jack makes it much easier, but I have done it alone.

 

3 more questions, if it's the pump-

1- can I just replace the pump in the sending unit housing? That would save quite a bit of money- the whole unit is about double the price.

2- any brand recommendation? I am reading bad things about Airtex and Carter. My options are Airtex, Carter, Brute Power from Rockauto, Spectra, Delphi and Bosch. I have no interest in the complete no names available from China. Motorcraft is not on the price spectrum for me right now, so it's not an option.

3- I am in California. What is the difference between the Federal and the Cali sending units if I replace the whole thing?

Thanks,
Michael

 

Where are the rednecks and starting fluid?

 

Yes, you can do just the pump

 

In this recent thread I posted a few pictures to show the differences between the Cali and federal pump assemblies. https://www.ford-trucks.com/forums/1...fuel-pump.html
Double check that your Cali EX is an actual Cali spec by looking at the emissions sticker under the hood.
I used a complete Motorcraft assembly, I have no recommendation on which pump cartridge to buy.

 

I did some troubleshooting today. Pulled the tank side of the filter, dropped the line into a gas can and turned the ignition to on. Relay sound in the engine bay, no sound from the tank and nothing coming out the fuel line. So, I pulled the 3 pin connector off the intertial switch and put my V/O meter in the outermost wires. I got no reading off the middle wire, have no idea what it is.

On the two outer wires, I turn the key to on and it popped up to 12v for a second and then slowly dropped down to nothing, like a capacitor discharging. If it was a dead pump, I would figure fail state would be either open, in which case there would be no continuity to ground through the pump and there would be no reading, or closed, whereby you would get a constant 12v as it shunted to ground internally. Why would it start at 12v and slowly bleed down?

any ideas? Also, does anyone have a wiring diagram for the fuel system so I can see what wires I am actually working with here, as well as the wiring diagram on the relay so I can check that, too?

Maybe I am grasping at straws.

-Michael
​

 

Sorry if they are sideways. Had to use the kids iPad.

 

Disconnect the inertia switch wire. Hook a 12V+ to the PK/BK wire to the fuel pump wire, circuit 787 above, the pump will either work 100% or it will not. You will have your answer in 15 seconds.

You can't rely on the PCM to check the pump itself

 

PS: I use a remote engine start switch that mechanics use. That way I have clips and enough wire.

 

Thanks everyone. Looks like a new fuel pump for me. The battery is reading 12.37v, when I jumper to the pink/black line, it starts at 8.6v and winds down to 0- I think there is a partially open winding in the motor that heats up with voltage applied until it causes so much resistance nothing can flow and it shows an open 0v.

Anyway, thanks for the help everyone- time to drop a fuel tank.

-Michael

 

This is exactly how my car acted when the fuel pump died... Sorry for your loss, but a new fuel pump should solve your problems.

 

Almost there. I got the tank dropped, new pump, new rubber hoses up top, got it back into position...

and playing heck trying to get the mounting bolts back in. The back bolts went right in, no problem. The front bolts are tight. I was able to finger tighten them in a couple threads, but then it got tight using the impact to get them back in, and they totally stop without driving any further once the unthreaded part is sticking out of the nut completely.

oi.

-Michael