the point of both pumps is redundancy. The facet is what I'm going to go with though.

 

With the Facet you will not need redundancy these pumps have life spans of over 10,000 hours and will pump fuel with a pile of trash in it with no issues. That pump will still be working long after the rest of your truck has turned to dust.

 

Thank you! At this point an external pump seems the most reasonable and reliable solution. Questions please:

- I will need to modify the fuel sending unit to delete the in tank pump and extend the pickup tube to the bottom of the tank. I plan to use an external fuel filter before the pump, do I still need an in tank fuel strainer? If so, do you have any recommendations?

- the power to the stock fuel pump is stepped down by a resistor wire. Does the Faucet pump need a full 12 volts, or does it run on the lower voltage?

- any advice on working with the stock nylon fuel line? To plumb in the external pump I’m thinking I’ll just convert over to rubber fuel hose.

many thanks!

 

Thank you! At this point an external pump seems the most reasonable and reliable solution. Questions please:

- I will need to modify the fuel sending unit to delete the in tank pump and extend the pickup tube to the bottom of the tank. I plan to use an external fuel filter before the pump, do I still need an in tank fuel strainer? If so, do you have any recommendations?
I don't think you have much choice except to extend the pickup with a compression fitting and a piece of hard line, and leave it wide open. I was looking for a sending unit for a diesel that year, which would have the return line connection and no pump, but most of the stores don't sell them anymore.

- the power to the stock fuel pump is stepped down by a resistor wire. Does the Faucet pump need a full 12 volts, or does it run on the lower voltage?
It probably would run fine through the resistor, but if I knew where it was I would cut it out.

- any advice on working with the stock nylon fuel line? To plumb in the external pump I’m thinking I’ll just convert over to rubber fuel hose.
My diesel has the nylon lines. Their OD is exactly the same size as the ID of fuel hose. I just slip the hose over the metal fitting of the sending unit and use a hose clamp, and then slip it over the plastic line and gently tighten it over the nylon line. It works well, haven't had any problems doing it that way. On mine, the supply is 3/8 OD nylon and the return is 5/16 OD nylon

 

Dropped the tank again in record time. I guess it’s true, practice makes perfect.

I have a big fuel filter mounted on the frame rail about half way between the tank and the motor and If it’s not too far for the electric pump to draw fuel from the tank the area just forward of the filter would be an ideal place to mount the external electric pump.

The blue line is the nylon fuel line and it would be relatively easy to remove the 4 foot section between the filter and where it connects to the metal lines that run forward to the engine bay. Looking at the nylon hose has be wondering if I could just cut the fittings out of the nylon hose and insert and clamp them into regular rubber fuel hose. I do like the way the factory fittings slide on and off and it would sure make the connection to the metal hard line simple.

As for the power supply, it would be easy to spice into the fuel pump hot wire at the fuel pump relay pigtail. That would provide all the factory safety features and give full voltage since it’s also ahead of the resistor wire.

Thank you again Matthew for the fuel pump recommendation, that looks like just the ticket.

Any other suggestions, recommendations and advice are much appreciated!

 

Do not put a filter before the pump this will restrict and stress the foot valve in the pump and result in early failure . At most run a mesh sock in the tank. And really these pumps can move lots of trash without hurting the pump.

Remove the resistor, do not leave it in place. The pump will need a full 12V to operate properly and meet specs for flow and pressure.

The pump hadsNPT threading so you will be able to buy nylon/PTFE compatible hose barbs. You can then leave the nylon in place and just fit the pump in line with the existing fuel lines.
Do not change to rubber leave the plastic in place or upgrade to a braided PTFE. Time to leave the rubber fuel line in the past where they belong, nylon braided PTFE is what we should be trying to use going forward.

 

I don't like full fledged filters on the suction side of the pumps either, but this one came with one and they said the warranty would be void if you do not use it.

https://www.facet-purolator.com/wp-c...C_1-cube-E.pdf

 

In tank fuel pump delete complete, i installed an external Facet fuel pump on the frame rail.

Compromises. While I would have preferred the recommended 40109 because it has a check valve and bigger fittings they are hard to come by here and Facet doesn’t seem to make a pre-filter for them.. however NAPA had a 40106 in stock along with a fancy Facet pre-filter so I went with that. I also fell back on 3/8” rubber fuel hose for a section to get the job done and get back on the road. Assuming the pump installation passes the summer driving and camping test I can upgrade to more modern hose when I have more time during the winter off season.

Ideally the pump should be mounted as close to the tank and as low a possible pointing upward at a 45* angle, and someday I might fabricate a bracket to get it closer to the tank and down lower but for now it’s mounted about 3’ forward and the filter inlet is about 3” above the bottom on the tank, but the lower end of the fuel line as it curves upward to the pump is about even with the bottom of the tank.. so hopefully that will give decent siphon action on the suction side.

I ran a wire from the pump and tapped the original fuel pump power supply line at the fuel pump relay (where it’s still battery voltage) and also tied in the primer circuit from the i terminal on the starter relay so it operates the same as the in tank fuel pump with all of the factory safety features.

I only had 5 gallons of gas in the tank and Initially the pump did not want to prime when I put power to it, and it sure makes a rattling racket when it’s sucking air. Ultimately I found it necessary to hook a canister fuel pump to the fuel line up near the engine and that one was able to pull the air through the pre-filter, pump and lines. After that the cube pump worked great. I measured 6 psi fuel pressure at the engine and strong flow.

Once I got it buttoned up I only had time to drive to the gas station for a fill up and then a 5 mile test run. Felt good under heavy throttle and short bursts of the secondaries Looking forward to doing some more testing before heading back over to the coast for a few days.

thanks again for your advice and encouragement.

 

Yes ideally you want one with a check valve with the check valve they are self-priming relatively quickly. I have never used one without a check valve in it so I can not comment on how it;s long term operation is going to be.
The pre-filter is a good idea and will keep out the larger pieces of trash.

The only thing to note is the spade connector, it will need some protection from corrosion. Since this is not a sealed connector the best solution would be to fill the inside of the connector with some NOALOX. This will stop any and all future corrosion issues.

You should have some NOALOX in your toolbox regardless. It is the world's best low temp anti-seize ,i know not its intended purpose but nothing works better especially in dissimilar metal applications (aluminum wheel rims for example), And is an excellent anti corrosion joint compound for single connector electrical connections. (do not use in multi-pin connectors unless you are going to carefully apply sparingly to each connection in the connector).

If you do not have any NOALOX then the old standby of White lithium grease or die electric grease will suffice.
Be sure to get the backside where the wires insert to the blade connectors also to stop water/moisture intrusion. This is where NOALOX shines as it migrates, and will migrate up the wire a bit to stop ANY chance of corrosion induced failure.

NOALOX can be had from any hardware store or electrical supply. The ones I recommend are NOALOX actual from Ideal or Burndrys PENETROX A (See below for each) These are the best on the market for what we would use them for. A smear of this on AL rims or rotor backing or bolts going into or through aluminum stops ALL dissimilar metal or galvanic corrosion even in saltwater aplications. Before warned this stuff does NOT wash off/out so avoid getting it on yourself or your clothing.

As a note avoid some of the other joint compounds like Alcoa's ALNOX this is a true joint compound and has grits in it to cut through Alminium oxides during joint assemebly. The grit in the product does not make for a good anti-seize obviously.

Regardless great job on the install, you put it in a spot that is open and easy to service and it almost looks like a factory install minus the non factory looking spade connector.

I think this eventually is going to be the default solution to replacing these early 460 in-tank pumps.

 

where is the fuel pump relay located on an late 84 early 85 f250?

 

Check the firewall outboard of the brake booster. I think the EVTM show's
I think I gave you that link.

https://www.garysgaragemahal.com/1984-evtm1.html

 

What engine?

 

460 single tank.

 

It could be on the side of the engine if it's mechanical, and a lot of the 460's had what they call a "hot fuel handling" option. If yours has that, the pump is inside the fuel tank. The mechanical pump will usually be on the passenger side lower front corner of the engine.