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Discussion Starter #1
My truck is finally back on the road. I never definitively knew what the problem was so the dry rotted connect hose at the gas tank must have been the problem.

I tested the fuel pump with hoses in and out of a gas can. The pump does in fact pull fairly well but obviously you have to have a vacuum on the line into the tank for it to pull gas.

Along with kludging up a filter sock I also had to find that asphault/paper tape insulation and I couldn't find anybody that sells that either. I wound up using foil faced peel and stick window flashing from Lowes. A little trimming and double layering and it worked fine.

The engine is running different(better) than before. After running it a while it had a tendency to want to idle up. Now it stays rock solid. It also seems to crank a bit easier when cold. I don't know what that was unless having the fuel pump that close to the carb might have been overpowering the float a little. It did gas smoke some on initial crank up. I had also noticed it starting to surge and go flat on me going down the road before the fix. That was probably from fluxuating fuel pressure. All that is gone now.

I had a couple of final challenges putting it back together. Once I got the tank in place and bolted up, the filler neck hose was crimped shut. I tried to pop it open with a bit of curved rebar but no joy. I pulled the tank yet again and finally figured out that the hose had developed a memory and I had it clamped on upside down. Rotated it around and it was fine. Since I was doing this by myself I used a couple of jack stands with pieces of 1 x 6 on top to hold the tank up so I could work it into place. It would be a lot easier with a second person.

I discovered that the screw on filter on the front of the carb was leaking gas where it was crimped together.

I didn't bleed on this one so technically I guess it was not a project. I do have 1 smashed finger though. Does that count?
 

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So you were unable to find a replacement in tank filter?

I was going to suggest this (see attachment) in lieu of using the in-tank filter, but CRS hit again. It appears as an inline filter (not filter per say) but is actually a 10 micron screen that can be serviced easily rather than dropping the tank when the tank filter (actually screen) fouls. This will protect the pump from tank debris. Of course, the OEM screen would be discarded.

You would also use a 60 to 100 micron fuel filter between the pump and carb to protect the carb.
 

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Discussion Starter #4
Its the old nylon mesh filter sock they put on the end of the pick up tubes to keep major tank trash out of the fuel line. These things generally don't ever need to be serviced but you may need to replace one every 25 years. The only way any of my suppliers would sell me one was to sell me the whole plate, pick up tube and gas tank sending unit with it.

Just leaving that off is not an option or putting a filter somewhere else is not an option. A sock needs to be on the end of the tube. The fuel level sending unit is down in the tank on that tube. If a bug or some other something got down in there and was sucked up into the pick up tube it could stop it up and jam up the fuel sending unit. Then the only way to fix it is to drop the gas tank.

What I did will work but I am going to ratchet on my suppliers until somebody starts selling this little plastic part.
 

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You can get almost any filter sock from pump suppliers, but I'll have to do a number lookup. What year is that? Any chance you have the Ford part number? Or the diameter of the pickup? Or a few multi-angle pics of the old one?

David

Typical 1" OD 5/16" ID pickup filter. About $7:
 

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Its the old nylon mesh filter sock they put on the end of the pick up tubes to keep major tank trash out of the fuel line. These things generally don't ever need to be serviced but you may need to replace one every 25 years. The only way any of my suppliers would sell me one was to sell me the whole plate, pick up tube and gas tank sending unit with it.

Just leaving that off is not an option or putting a filter somewhere else is not an option. A sock needs to be on the end of the tube. The fuel level sending unit is down in the tank on that tube. If a bug or some other something got down in there and was sucked up into the pick up tube it could stop it up and jam up the fuel sending unit. Then the only way to fix it is to drop the gas tank.

What I did will work but I am going to ratchet on my suppliers until somebody starts selling this little plastic part.
A sock does not to be on the end of a pickup tube. Do HI-PO pickup assemblies use a sock?

If the in-tank screen fouls, you have to drop the tank. An inline screen as I showed only requires an insert change outside of the tank.

AGAIN! If one insists on replacing this filter type rather than modernizing the fuel system, the FORD SERVICE PN BASIC is 9A011. One is made for a 5/16" inlet and one for a 3/8" inlet.

Personally, I would take that thing and toss it as far as I could. This is thirty year old tech, not something one would want in a current performance car.
 

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I'd generally agree, but this is not a hipo application, and the original went 25 years (which is short in typical sock lifetimes), so I don't think it's critical here and probably won't need another for 25 years. Damn cheap too. But I'll go with the suggestion of an external pickup filter on general principle. I would make a correction that the pickup filter (pre-pump) should be the coarse filter, and the post-pump filter (pump to carb or injectors) should be the fine one. Pumps will cavitate sucking through the finer filter first, but they can push fuel through them easily.

David
 

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Discussion Starter #8
I agree if its a hot rod you don't necessarily need a sock but they don't slow anything down. I run all fuel through a filter strainer going into my mustang. If you don't run a sock it would be wise to filter everything you put in your gas tank.

I have external, in line filters on everything as well. This is just for my old 79 F150 pickup truck that I fill up at the gas pumps and some times they have trash and bugs down in there. My sock looked like this only it was black.



I think that after 1972 they switched to 3/8ths line or at least the part is different somehow because it is listed as a 73 to 79.

Well carp, so now I find one. Tom's bronco parts sells em. Still, 20 bucks for a 2 dollar part.
Fuel Sending Unit Filter - 73-79 Classic Ford Trucks, New - Toms Bronco Parts
 

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The reason your sock was black was from the rubber filler neck deteriorating and that being the place everything in the tank goes to it took the brunt of the rubber pigment. Almost all pump socks I see are either brown or black. Modern vehicles using more neoprene than rubber have the brown socks, and older cars have the black ones.
 

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I like white socks. :D Yeah, it's a D1AZ-9A011-A to get your 3/8" version that all 67-79 F-series used. Some cars use the smaller D1FZ- version at 5/16". I'll see if one of my suppliers has them for individual sale, but this guy on FeeBay has them for less than the restoration places at least. I change to a larger filter from Jeep Cherokees IIRC. It just happened to be a good swap meet deal for 10 large 3/8" pickup sock filters.

David

PS: I run sock filter on almost everything including hipo. My theory is - if things are bad enough that sock is clogged, the tank MUST come out anyway for decrapifying. So, it's sort-of a method for me to do what needs to be done so there is no temptation to shortcut by only changing an external filter. That's just me.
 

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PS: I run sock filter on almost everything including hipo. My theory is - if things are bad enough that sock is clogged, the tank MUST come out anyway for decrapifying. So, it's sort-of a method for me to do what needs to be done so there is no temptation to shortcut by only changing an external filter. That's just me.
I am not trying to be argumentative (yeah, right), but if one used an outside inline, during the scheduled screen change, you would know if the tank is fouled and needs to be pulled. Not so with an in-tank filter as it would only cause pressure deviations and would be the last to be diagnosed.

They used this type of filter for a reason, it costs very little and they also make money pulling tanks.
 

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Not so with an in-tank filter as it would only cause pressure deviations and would be the last to be diagnosed.
OK, I'll give you that one. While I immediately know the symptoms of pump intake restriction, the average hobbyist likely would not. It would be simpler and more obvious for them to check the external filter tying to figure it out. Good point.

David
 

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Discussion Starter #13
Well I spoke too soon. After all that work my truck quit again right in front of the local Shell gas station/ convenience store where I buy my gas. We've had some cooler days and I haven't driven any significant distance in it until yesterday. I pulled in to the store to get coffee and when I came out the truck wouldn't start for about another 5 minutes.

It looks like it is, in fact, a vapor lock problem. Granted, the other stuff didn't hurt and was probably good for me to have done anyway. A couple of the things I did needed to be done.

Something in the formulation of 87 octane gas has to have changed as of this spring because I've been running it for 6 years since I rebuilt the truck and it just started quitting on me like this.

I put 6 gallons of 93 octane gas in it just to see if that would help. I'm testing that right now to see if it fixes the problem. My understanding is that 93 has ethanol in it too so why would this work?

Engine temp never runs even half way up the gauge so it is not a matter of the engine getting too hot.
 

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They remove the ethanol from the fuel blend somewhere in SEP for the winter season (one reason fuel mileage seems to suck in warm weather). It may be the fuel is percolating (remember, ethanol vaporizes @ 160 degrees) leading to evaporation out of the bowl vents as well as possible vapor lock/blend separation.

But you are OK in the repairing of the lines and in-tank filter (as it was obviously needed)... :)

Find ethanol-free E0 gas stations
 

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Discussion Starter #15
The 93 octane helped some. I just made a run that would be guaranteed to cause it not to crank. I only had a slight problem and then it fired up.

I'm going to try the methanol gas stabilizer additive next.
 

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Discussion Starter #16
My motorcycle has been acting up for a while too. It was hard to crank and would pop on deceleration. I have bumped it to 93 with the Lucas stuff. It cranks easier now and runs a whole lot better. I have been running it on 87 octane for years until this year. It is a 1500 big V twin bored out with twin carbs, K & N's fresh air, free flow exhaust and carb kits in the carbs.
 
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