85 Ford F-800

I just got the above mentioned truck and have been waking it up from approximately 5 to 7 year slumber. After removing the entire heater box and heater core to remove the stinking rats nest and washing the entire vent system with pine-sol, I have moved on to the engine.

While I was changing the oil, I noticed the fuel pump (370 gasser) looked like it has a filter attached to it. Does anyone have any experience with these? Is there a filter at the fuel pump? Also, there is a fuel filter near the gas tank as well. Is there really two fuel filters on this truck? I have never seen that set up. Does it take a special tool to remove the one on engine?
Also, is there an electric fuel pump in the tank as well?

Thanks for the help.

If it screws on there should be a filter in it that is the only one. It should also be the only pump. A lot of thanks can get mixed together over the years. Look it over.
I normally used channel lock pliers.

Cartridge filter at the pump should be the only filter, Wix #33271. https://www.oreillyauto.com/detail/...pumps-fuel-pump/m20012/6090843?q=M20012&pos=0

I will try and get some pictures of this, but right after the tank, there is a small spin on filter, and that leads to a fuel pressure regulator, that is at the passengers rear corner of the engine, then the fuel line goes all the way across the engine to the mechanical pump (that has the small canister filter on it) and then back up to the carb.

So if it has a pressure regulator on it in between the tank and the mechanical pump, wouldn't that mean there is some sort of pump in the tank?

Also, there are 3 sealed lids on top of the tank. One large one about 3.5 inches in diameter and two other smaller ones. The large one has the main fuel line coming out of it, and an electrical connection. One of the other ones is electrical only, probably the fuel gauge sending unit, and the third is a smaller fuel return I am guessing.

Does anyone know if there are some fuel line schematics out there somewhere that would show me the original fuel path?

Thanks,

a lot of the medium-duty gas jobs from ford, gm and ih during that time frame used an in-tank electric pump. if i remember correctly, they routed the power supply to the pump through an oil pressure switch and/or relay to prevent the pump from running if the ignition was on and the engine not running

Thank You for the info.
So they used the electric fuel pump in the tank and also used a mechanical pump as well?
I need to find out if both of these pumps were original, or someone added the mechanical somewhere along the way to try and fix an issue.

I have noticed that when this trucks sits for a couple of days, it won't start when choked and pumping the foot pedal. I have to spray carb cleaner into it and it starts right up, stumbles a little bit and then smooths out. It seems it is not getting fuel until it fires on the carb cleaner and then takes off.
I need to rebuild the Edelbrock Carb on it, and investigate the fuel system on this truck and find out what is going on.

I thank the pumps were one or the other.
They never came with an Edelbrock but I saw a small fleet that did well with those.
Check the fuel pressure and volume at the carb after it has sat for a couple of days.

Thank You for the help. You are correct, this truck would have come with a Holley I believe. Someone along the way put this Edelbrock on it. I took it off last night, and the secondaries are frozen shut, and have dirt and debris in them, so I am guessing it was exposed to the elements during its 5 to 7 year slumber. I am not sure it is even re-buildable at this point. i haven't gotten it torn down. I sprayed the secondary throttle plates with a bunch of PB Blaster to see if it will break lose. I had an old Carter AFB off a Buick nailhead with the same issue and I soaked it in PB and brought it back to life. I might be able to save this one. These Edelbrocks are jetted for a car in street use. I wonder if I should jet this thing a little heavier for the hard pulling this engine is going to be doing?
I am going to put a fuel pressure gauge on it to see where my pressures are.

As far as the fuel pump goes, I wonder if it had the electric pump and it quit, so they put a mechanical one on there instead of replacing the in tank pump? At this point, that is still a mystery. I did find the oil pressure sending unit that I think fires the electric pump. An oil pressure line coming off the back of the engine is running to two sending units. One is a single black wire, probably going to the oil light in the dash and the other sending unit is I believe 4 red wires that could be the switch to the fuel pump. There is also a lead to the brake system that signals the electric brake to kick on when the engine dies.

As a reference, I am attaching some pictures that show the top of the tank, filter1, regulator, and mechanical pump/filter2. There are 3 openings in the tank.
Thanks again for your help. I want to put it back as much to stock as I can. I am just trying to figure out what that is.
.

some guys by-passed the electric pump because they were pricey and hard to access. the electric pumps did not like dirty fuel. guys felt the mechanical pump was easier to change and usually cheaper. bottom line-use clean fuel

Both of those screw on cans should have a filter in them. Trucks normally only had one and one fuel pump.
Someone may have dropped in a used engine and you are blessed with two of each.

Lucky me!!
I have no idea if the electric one even works or not. When you turn the key on all you hear is the electric brake motor screaming at you. I am going to take both of those filters off and replace them. I am also going to turn the engine over and see how much fuel comes out of the fuel line. I have not found anyone that actually has one of those tank filters in stock. I was thinking I could just put an aftermarket electric pump on there, since it already has the regulator.

I got the carb apart last night and it is the worst thing I have ever seen. There was so much water and corrosion and dirt in that carb, that I don't think it is fixable. You can even see the secondary jets in the bottom of the carb because they are covered in so much gunk and crud. The secondaries are still frozen shut. I have it soaking in PB Blaster to see if I can get them to move again. I don't have any idea how that truck started and ran based on the inside of that carb. The accelerator pump was completely shredded.
So if I have to replace it, do you think I should go back with the Edelbrock 600 cfm that was put on years back, or go back to the original style Holley?
I just want to make sure the jetting is heavy enough to keep enough fuel to the engine under hard pulling.
Thanks,

They ran great with the Edelbrock just no governor. The last time I bought one of the Holleys was about 25 years ago. It was $650 back then.
It will work great with a mechanical pump and an inline filter before it. The hell away with all that other junk.

The saga continues. I went searching in my storage unit for a Holly that I knew I had that was rebuilt, but never used, and in the process I found an Edelbrock just like the one that came off this truck in very good condition. I thought I had traded that carb off years ago, but there it was. 600 cfm 1405. I just gave it a quick clean and put a kit in it, and it should be ready to go.

As you can see in the pic below, I have taken both fuel filter canister's off. The issue is that the smaller can had a pin hole in it and was leaking just a small amount of gas. Also, when I clamped down on it with filter pliers I bent the can to the point where it isn't usable. Does anyone know where I can get that short can? I can get the larger one, but I haven't seen this shorter one offered out there. Could there be another application, such as marine use or somewhere I could look to find it? They both take the same filter. If I can't, I guess I would have to remove that filter from the fuel line, but that won't be easy because it is right by the fuel tank.
Thanks