I have a 1954 Ford F100 with a 1972 351 winsor engine in it, It has a Motorcraft 2 barrel carb on it, tag # is D3TF. It will sit and idle in the garage for an hour. The problem is when you take it out on the road it shuts off on you. First I thought the problem was electrical so I put a new coil,points and condenser and cap and rotor on it. Now it still shuts off so I thought it was fuel related. I put a new fuel pump, new fuel filter and new rubber fuel lines on it. The fuel tank was taken off several years ago and sent out and was cleaned and coated on the inside. The truck has sat for appox 4 years with occasional start ups. I have taken fuel out of the tank and it appears clear with no signs of a problem. I have put fresh gas in it. 1st time it shut off was at 60 mph on a freeway. Other times were just driving it locally. I am afraid now to take it out of the garage. Any ideas?? Please help. Thank you

 

How does it shut off?

Does it stumble or does it just die....at once?

 

How mechanically inclined are you? How far can you go before it cuts out? Does it start right back up or after sitting? One thing you can try: with the engine idling, wiggle the small wire that goes from the ignition coil to the distributor. They are notorious for breaking internally where it enters the distributor causing intermittent cot outs. Also the coating that was used on gas tanks 10 years ago is not resistant to deterioration with today's unleaded gasahol. I would drive it on local roads until it cuts out, immediately shut off the ignition, shift into neutral and coast to a stop off the road where you can work on it. Pull the float bowl cover off the carb and see if it is full of gas. If it is empty you have a fuel delivery issue. Check for debris in the bottom of the float bowl. Is the area of the carb where the fuel line screws into the carb swollen with a large thin hex nut that the line fitting screws into? If so, unscrew the fuel line, then unscrew that large nut, it's a plug that should screw out (be careful not to lose the gasket or the spring behind it as you take it out. Behind that plug is likely to be a sintered metal filter (looks like a small cylinder made of pressed together tiny brass or copper beads). If there is one, take it to the parts store and buy a matching replacement for it. That final filter gets gummed up with varnish when sitting for a long time.

 

Thanks for the tip about the little wire from distributor to coil, AX! Just realized that would make a lot of sense why my truck would cut out, die for a few seconds, then come back and backfire all that extra fuel built up. Thought that wire was a little flimsy and frayed.

Back to your concerns though. I would be looking at the carb personally. I would feel strongly inclined to do a thorough rebuild and cleaning. They're not that difficult and there's plenty of very helpful videos on youtube to rebuild pretty much any carburetor. But I like doing stuff like that.

 

That's the key to whether it is electrical or fuel. Fuel almost always sort of sags over several seconds at least. Electrical is usually instantaneous, although a bad coil can sometimes kick a couple of times before shutting down.

 

on the freeway it stumbled; being driven locally it just shut off; thank you for your help

 

I would not call my self a mechanic, I am probably more referred to as a parts changer but I am trying too improve. I will try all your suggestions. You gave alot of great ideas. Thank you for your help

 

on the freeway it stumbled; being driven locally it just shut off; thank you for your help

 

I would not call my self a mechanic, I am probably more referred to as a parts changer but I am trying too improve. I will try all your suggestions. You gave alot of great ideas. Thank you for your help
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lol on "parts changer", good one!

 

"Parts changer".....that is a keeper! Yes, check all wires, cracks in coil, and maybe just a defective coil on its last leg. Could be a clogged fuel filter. My .02cents worth.

 

I'm fond of using a transparent throwaway fuel filter installed between the fuel pump and carb. That way I can see if the engine is getting enough fuel while running.

 

The most common cause of continued highway stalling aside from dirt in the fuel system is a non-vented fuel cap. Our trucks are designed to use vented caps. They are sometimes hard to find locally. Macs refers to them as non-evaporative: Search Results For: Fuel Cap For All Years And Models Parts & Accessories.
You also might want to read the text under the picture on this post:
https://www.ford-trucks.com/forums/1...l#post15585283

If you are still having problems then I would suggest pulling the top off the carb and looking inside just to make sure that your cleaning didn't miss something.

Then I agree with AX on using a clear fuel filter. This is the one that I use but there are many others: Ford - Inline Fuel Filter - Universal Style - 5/16 Inlet & Outlet - Chrome With Glass Body - Macs Auto Parts

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If you can not find anything else a friend of mine had a similar problem. The engine would just die. He figured it was an electrical problem. It took a little while but finally found it. The little ground strap that connects the breaker plate to ground inside the distributor broke in two. Depending on throttle position and the breaker plate position most of the time they would just touch together. But give it part throttle and the vacuum advance would move the breaker plate and separate the two broken ends of the ground strap. Thus no ground to the points and an instant stall. Sorry if I missed that someone mentioned this earlier.