Will not stay running

I think you are on the right path that is most likely an air/fuel ratio issue however, if this engine is cold, it looks like the choke is wide open. Is that true or am not not seeing this correctly?

If the choke is wide open when the engine is cold then it is going to stall out. My father in law has a 1956 Lincoln and his starts and stalls just like this when the choke is hung open.

Before you adjust anything, see if you can release the choke and it shuts and then start the engine and do not use the accelerator and just see if it idles. If it doesn't then hold it with the accelerator so that it doesn't stall until it heats up and once it is warm if it keeps running then we need to adjust the carb and choke for cold operation.

Just for giggles.

What kind/type of fuel pump is on it?

Sounds like the carburetor to me.

Run your mix screws in (one at a time)

Count the number of turns (I like 1/4 to 1/2 increments so I can keep better track) Record the turns so that the numbers can be remembered.

When you hit bottom, just lightly touch it, going tight will ruin the seats.

Now back both screws back out to their original number of turns (which should be equal).

Give it a try.

Any better?

If not, back both out an additional 1/4 turn each.

Any better?

If not, put them back as they originally were, we will try something else.

The Medic

This may sound really dumb, but it will not hurt to try it!

Outside away from everything! Never can be too careful!

Always be ready with a soaking wet towel (a smothering throw), and a fire extinguisher as your last line of defense. Perform this outside. Just in case something bad might could happen when dealing with fuel.

Get a wash rag or similar rag.

Submerge it in water until it's thoroughly soaking wet.

Give it a little squeezing, just so its not so drippy.

With a little help, see if you can get up to about 2,000 RPM's. Maintain it for a few seconds.

Quickly cram and hold the wet rag over the carburetor throat let it die from 2000 to zero. (You may want to practice the rags "fit" before you actually perform the task) You want a really good rag seal on the carburetor when you choke it down.

The object here is to get the 2000 RPM's suction action to sort of vacuum out the inside of the carburetor/passages when you fully seal choke it out with the wet rag.

No that it is dead, it is really flooded!

Replace the breather (this will deter possible flames if something were to happen)

Hold the throttle down (fully open) and crank it, this should suck the surplus fuel on down the line and allow it to start.

I would try this once, but no more than two times. I've had good results doing this with my Jeeps, if something internal may have been blocked.

Any positive results?

The Medic

Next thing to test might be the fuel pump output.

Take the fuel input line off of the carburetor, and put it into a jar (or something that will hold a half gallon and also be see-through).

Turn on the fuel pump for 30 seconds while monitoring your jar as not to overfill it.

Shut it off after the 30 seconds has passed (or if it gets too full!)

Without any specs for the electric pump, a mechanical pump should generate at least a pint of fuel in the 30 seconds.

If your electric pump is not pumping, at minimum, the same as a mechanical pump would do, you may have a pump problem.

My pic shows the test process, the pic is showing a mechanical pump (pic I had on hand).

Basic where? M.O.S?

The Medic

Is the vehicle at operating temperature when it revs and still don't idle?

If it does get to operating temperature, then you do a quick throttle actuation, does the choke come off fully (the choke butterfly is now vertical--the choke is off).

We should not permanently adjust anything except at operating temperature/ choke is off.

Will it idle and get to operating temperature?

Keeping your mix screw recorded turns on hand. If nothing works below, put them back to the original settings!

You said 3-1/4 was the most. Get both to 3-1/4. (Back the right side out the extra 1/4 turn).

Try it. Results?

Bad results?

Back both out to 3-1/2 turns (1/4 turn more than it was)

Try it. Results?

Worse/ still not right?

Lets go the other way now. Take both back in to 3 turns (out from bottoming).

Try it. Results?

No Go?

Let's try 2-3/4

No go?

Put them back to the original positions.

My Pap Retired AF '54-'74. I was in the 4th grade then. By that age I had already gotten bit by the Jeep bug and was destined to be a paratrooper.

If the ole Ford ain't working out, Maybe I can sway you into a Jeep CJ!

The Medic

So what (if anything) of what I suggested made any difference?

This would require a little bit of easy translating Jeep to 'Stang, it might save some fund-age. Basically its the same set up.

https://www.2carpros.com/questions/jeep-cj7-1985-jeep-cj7-stalls-when-hot

My 1st want was a Willy's, I found I did not have the time or place to fix one up. Most any that I found back in the 1980's needed major help and there was no internet for help. I got "Willy" in 1991.

I suggest a CJ 5 or 7 from between 1979 and 1981 as a daily driver, those were the years that everything was perfected and just before they ruined things with a computer and disposable aluminum transmissions.

The 5 or 7 will keep up in traffic and is better adapted for longer trips.

The Willy's is more of a pleasure/cruising vehicle (45-50 MPH) that not only will impress everyone else, but deep inside you will be impressed every time you think about/ drive/ or just sit and stare at him!

Let us know how the 'Stang works out, a pic would be nice too!

The Medic

Both types of Jeeps are still available.

Get her what she wants and she will gladly assist you with getting a Willy's!

I'm hoping you can get the 'stang going without spending a bunch of money!

Still no pic of yours!

One of my Jeep buddies (he has a 1942) drove his 1970 Mach 1 over yesterday so we could charge the A/C. It will never compare to a having a Jeep!

The Medic

Good looking cars. By far my favorites of all muscle cars.