Just to be clear; In the pictures you posted the dirty fuel bowl was the secondary and the clean fuel bowl was the primary.

The accelerator pump housing and diaphragm lives on the underside of the primary fuel bowl and you can clearly see the pump housing on the bottom of the clean fuel bowl.

Additionally, looking at the dirty side of the main body of the carb you can see; the secondary metering plate (not metering block as you would have on the primary side), no idle mixture screws down below, and on the upper right you can see the vacuum motor and linkage that actuates the secondary's.

Further, the truck would not drive on the secondaries. The secondaries are not connected to the throttle, they are vacuum operated, and only come in above 2700 RPM (or so) under heavy throttle.

Not here to argue, just want to advance understanding.

 

Anyway, the original problem was hard cold starts and I'm not sure the problem has been isolated.

In the last picture you posted I can see the choke flap on the top of the carb is not closed...it is open.

Was the truck cold (as in sat overnight) at the time the picture was taken?

To check the choke 1) the engine needs to be cold. 2) Pump the throttle to release the choke, the choke flap on top of the carb should close (maybe leaving only a slight gap).

Check the accelerator pump shot. 1) Hold the choke flap open with your fingers (assuming it closes like it should). 2) Look down inside the carb. 3) Pump the throttle, you should see a squirt of gas shoot out of the nozzle just under the choke flap.

Also, what about technique? When you are cold starting a carbed vehicle it helps to pump the throttle a couple / three times before cranking. This will 1) Set the choke and 2) the accelerator pump will squirt some extra gas down the carb to get you going.

Another symptom of a bad accelerator pump is a bad stumble off the line...without that extra shot of gas it will hesitate.

Now, with all that being said it is entirely possible your main (front) fuel bowl is indeed draining dry and you have to crank it for a long time to fill it back up and that is your problem. I just think it's curious that its not leaking externally where you can observe it...that's why I'm suggesting you check your choke and accelerator pump functions as part of your diagnostics.

 

I'm still thinking about why fuel would be running back out of your carb. I'm thinking with an electric fuel pump system your fuel line should remain pressurized after shut-down. I know mine does.

A lot of these rigs came with an anti-vapor lock vapor separator.

The main fuel line (a metal hard line) would run up the front of the motor to a small can (often mistaken for a fuel filter) and then on to the carb inlet.

Now attached to the side of this little can is another hard fuel line that runs back down to the frame rail and returns fuel back to fuel tank. The general idea I believe is to keep the fuel circulating so it doesn't stay in one place too long, get hot, boil, and vapor lock...

Anyway, if you had this hot fuel handling package, and you took it apart thinking the little can was a fuel filter, and then cobbled it back together somehow, then I could see a way for fuel to drain back to the tank...

 

This is the reason there is no vapor separator in his truck.
Not sure why fuel is draining back.
Perhaps there's a leaking hose/connection at the switch valve?

With an open return line in the Hot Fuel Handling system I wonder how there could be residual pressure in the system?

 

I appreciate that, i'm trying to learn as much as the next guy.

 

Since I don't drive the truck everyday, and I was looking for clarification...I snatched a photo of a basic 4180 Holley to use as a reference when talking about the accelerator pump. I was pretty sure where it was, but needed to make sure before I go to my friend with issues with his work.

The choke does work flawlessly, every time I start it, it'll idle up to about 1500 RPM and sit there either A. until it warms up, or B. until I tap the gas and then it goes down to around 900-1000 RPM.

Every time I go to start it cold, I step on the gas about 3-4 times. My first vehicle I had back when I turned 16 was carbureted so i've always stepped on the gas a few times when cold starting a carbureted motor.

Once running, the truck runs like a champ and doesn't stumble at all off the line. It used to before it was rebuilt. If I stomped on it, it would just die, so I had to constantly feather it off the line.

I think the best move from here is to look at the accelerator pump like you said.

 

Cold starts may simply = empty float bowls.
If that's the case no amount of pumping the throttle is going to squirt fuel into the intake.

 

What was that little can then? Because when I called Ford, he said it was labeled as a fuel filter and that they didn't make it anymore. LMC didn't list it, and I couldn't find it anywhere.

That can started to leak and was causing a huge problem under the hood. I noticed that the return line was originally capped off on the can, and the return line. The return line was there, but it wasn't being used (from what I can tell) from the get-go. When trying to inspect the can and remove it, I kinked not only the top of the can, but also the main fuel line, and since the truck was sitting in my dad's driveway, taking up space...I couldn't sit around 5-8 days waiting for a replacement line to come in from LMC. The old line was badly cracked and dry rotted, and i'm amazed it wasn't leaking in the first place.

Since I have electric fuel pumps, they should keep pressure in the line, or keep their prime. Right now, i'm only using the rear tank because the front tank was inoperative since I bought it, got it working now, but there's so much nasty gas and stuff floating around in it, I figured i'd replace it now and get it out of the way before I use it.

 

Now, would that be a case of bad accelerator/leaking accelerator pump, or could one of the bowl seals be bad, and that could be causing the fuel to run back into the tank?

 

Nothing in the carburetor is running back to the tank.

If the bowl gasket or accellerator pump diaphgram is letting the bowl go dry you're going to have nothing to pump into the bores of the carburetor when you go to start it.

 

Good point.

 

Agree 100%. The inlet valves do not stick down far enough into the fuel bowls for the gas to siphon back out.

Since the choke and accelerator pump appear to be working and you know how to start a carb about the only thing left is a fuel leak. Wipe the carb and intake down, let it sit for a day or two, and then feel around for gas.

In my case the through bolt that mounts the fuel bowl to the carb immediately above and to the right of the accelerator pump developed a leak and the gas ran down over the accelerator pump housing giving the appearance it was leaking.

Hopefully yours is the same and all you need do is tighten the four bolts that hold the fuel bowl onto the carb.

 

That's very odd, because I did just that. I was driving it around last week, had the vent on, and could do nothing but smell gas. So I popped my hood, and looked at my intake to see loads of puddles sitting there. I had my dad come out and look at it with me, and when I started it up, we saw that that can was leaking. I remember calling my friend about it and noticed the accelerator pump cover and gasket looked wet. While I had the screwdriver out, I figured, "well, let's look at the other screws just in case", and sure enough...the 4 screws that hold the front bowl on were loose. My dad told me to not over tighten them, but I bet that's what was making my accelerator pump look wet. I'll take a look at it tonight, and maybe even take it off and inspect it, and report back tomorrow.

 

The blue Holley teflon gaskets shouldn't take a set like that...

Did your dad notice if fuel was spraying while you were cranking, or only once the oil pressure came up?

 

The fuel was spraying out of that little can where the fuel line plugged into it once the motor was running. I had pulled into his house and turned the truck off and it sat for a while. Then when I came back out, I fired it back up, and it took about 30 seconds for the fuel to start dripping out of the line. So it only started leaking once the truck was running.