UDPATE - Stalling like it's out of gas... but tank is full.

Clogged fuel filter?

@Riley posted:

P.S. I just had a lot of work done that included new dual fans, aluminum radiator, a bunch of electrical work in the console/gauges. I have no idea if that has anything to do with what's happening... but my headlight motor also died after all that work. Maybe a coincidence, but just to put it out there.

Did the car run fine for awhile following all this work and just now started having problems? Possible ignition issue, especially considering the work in the dash.

Yeah, never had this issue before. I had driven the car maybe 2-3 times since getting it back from the shop and yesterday was the first time this stalling happened.

@piney posted:

Clogged fuel filter?

That came up in some searching here. That looks like an easy enough job for a dummy like me, no?

Does it start now that you are home?  It sounds like a loose wire or connector.  The headlights not working after the work being done sounds suspicious.  

...My first thoughts:

Fuel Pump, Clogged Fuel Filter, Clogged Main Jet(s).

Fuel Tank NOT Vented.

* Vapor Lock, Fuel Line to close to Header, or Carb Needs Heat Insulator.

Coil Bad, Points Closing-up-Burned (if the dist. is using points) Bad Condenser/Capacitor. COIL wired in REVERSED Polarity.

Spark Plug Wire(s), Coils High Tension wire, Shorting to Ground (May cause Backfiring).

Bad/Burned Ignition Switch...Bad Ground to All Ignition points.

Headlight Motor Wired 'Incorrectly' into the Ignition Circuit.

Bad/Failing Alternator/Voltage Regulator

There Are Tests for all of these conditions.

Very Glad You did not get Stalled In the Middle of the Freeway!!

Good Luck with it.

MJ

Last....If the Rad. Fans were to be wired, by Mistake and Incorrectly, into the Ignition circuit, everytime a Fan came ON, the Ignition would shut down.

@Riley posted:

That came up in some searching here. That looks like an easy enough job for a dummy like me, no?

...Check for Accelerator PUMP Shot!

MJ

I guess I will search for tests for all these potential issues... but it does not sound fun trying to figure out what it is. Was hoping it'd be like one or two potentials things...!

Did it run kinda rough before it died or just all of a sudden?  

Is there any chance you may have an air bubble in the cooling system after the new radiator install?  Might be worth checking the coolant level.

what electrical work was done?  

Ran totally fine, no signs of any problems, then just BLAGH... and dead. Even when I would get it started back up, it would run great for a minute or two, no signs of any problem, and I'd think "hey, all good!" and then it would die. Doesn't seem there's any rhyme or reason to it.

I had such a problem, Riley. Turned out to be a burned coil, such that when the coil was cool, the wires on the primary would be fine but when it got warm, they separated, broke contact and -no spark. When it cooled off the cycle repeated.

The fix was to throw the can-of-oil coil across the road into the woods (optional) and install a solid-state coil that was OEM from a newer Ford. It looks like a transformer. If thats it, you'll need to change your small coil wire ends from ring-connectors to male spade lugs. You don't need Ford's expensive molded plastic plug body.

A second possibility, if your car is a '71-72 with the early fuel tank, is a varnished fuel filter inside the tank where its not service-able.  You reach in thru the fuel sender hole with a wooden (non-sparking) stick and RIP the cloth filter off the welded end of the fuel feed line..If you have a ;73-up, there's a fuel filter clipped on the end of the fuel line. To R & R it, remove the sender and snap it off.   Autozone sells them for less than $5.

Thanks. I'll look into this and the fuel filter to start. I have a 74, forgot to say up front.

I don't have a woods near me... but there's a construction site nearby that I could use as a location instead.

The original configuration of the Pantera fuel tank has a fuel tube pickup that is welded to the interior of the tank and is separate from the fuel gauge sender.

It is steel. It has the tendency of rusting through at certain points along the tube. Most common is around 1/2 tank level but there is no guaranty where that hole in the tube could develop or when. That would effect the fuel pumps ability to siphon fuel through the tube because the hole would break the vacuum.

The only way to test for certain would be to set a separate pump, independent of the engine, and see if you get flow through it.

Mine rusted through at 1/2 tank. The car would run no problem with a fuel level above 1/2 tank. Then die at that level.

There is a replacement for the pickup tube that is part of the fuel level float sender. I installed that and it corrected the issue.

The other thing to check is that the tank vent is open and not clogged or closed. The original filter element used in the factory vent is a little funky and can clog due to age. That one I believe is riveted on. You would need to drill out the rivets to remove it.

If it is the original supplied on the US delivered cars you might want to put in the later type that has roll over check valve built into it?

On my car the factory charcoal fume filter is long gone so I vent to the atmosphere. It originally was connected to the tank vent and then breaths into the factory air cleaner. I've never heard of one clogging but it is part of the tank venting system and they were serviced new. The car is 50 years old now. So who knows it's lifespan?

Any one of these scenarios could cause no fuel to get to the engine.

I had a coil go bad on me at one point. I was headed home from a show in the left lane of 4 and it died. Totally dead just coasting. Had to maneuver thru 3 lanes of almost bumper to bumper traffic to get to the shoulder of the road. Hairy moment for sure.

I can imagine. It was a little hairy putting gas in it as I'm nearly on the freeway and semis are blowing past me... almost like they were enjoying it.

My bet is that your coil is on its last legs.  When it heats up past a certain point it fails and then when it cools off past a certain point it starts working again. These points are not precise which would account for the differences in wait time to restart and drive time to the next failure. If it was me I would change the coil first before checking other things.

I agree with Doug- it is likely an intermittently failing coil. A large number of carb problems are really electrical and the symptoms are the same.

One thing I forgot- if it does turn out its the internal fuel 'sock' fully varnished closed, do NOT use an air compressor into the fuel-out line to 'blow it off the end' or rupture it, as a few owners have tried. Ridiculously low air pressure will instantly turn the complex fuel tank into a big steel doughnut that will never again fit in a Pantera, or else rupture a seam. Our tanks are made of dangerously thin steel. They're only a couple of pounds heavier than the aluminum tanks found in unmolested  pushbuttons. Good luck-

Before going all over the place from "mine did the same and it was ....." already start by knowing if it's a fuel or ignition problem.
So, when it has just died, remove a spark plug and see if it is dry, which indicates a fuel problem, or wet which indicates an ignition problem.
To confirm, you reconnect the wire to it, you press it against an unpainted metal part of the engine, you operate the starter and see if there are sparks. It's much easier to do with someone's help.
If there are good quality sparks, ie blue, you can eliminate all electrical faults and search in the essence circuit. If there are no sparks, or of poor quality, i.e. orange or white then you can look on the side of the coil, connections etc...

Well, I agree with everyone. Our cars are really a Mustang in better clothing, and  what a hell of a ride. This is all basic trouble shooting to an issue that every car  from the 60's & 70's have. That is why I have one. No computer to throw out the window. Granted the newer stuff is great and reliable, but when it isn't then AAA is needed. I like the old carb and points that will at least get you home.

Ken