I have a 1979 f250 460, and sometimes i will be driving and my truck will just shut down. It doesn't matter the speed i am going it has done it at 5 and 55. Sometimes when i go in the store and come back out it won't start again. It will just keep cranking. Other times when it is cold it fires right up and other times it takes it a couple of seconds. It's getting fuel. Is it the ignition?

 

The first thing I would do is have the ignition module tested at a local auto parts store.

A very comon problem with Duraspark Ignition Modules is they fail when they get hot. After they cool down, they tend to work again. The problem will get worse until the module quits working altogether.

When you take the module in to be tested, have the counter person test the module several times to heat it up. It may not fail the first time it's tested etc...

Good luck.

 

When you get your new MOTORCRAFT module mount it 1/4" off the fender with some 5/16" hex nut spacers to allow cooling air under the unit.

Many perfectly good MOTORCRAFT ignition modules can be found in junkyards. Just remember cars had them to... Make sure you match the colors on the plastic grommet around the wires on the units. BLUE grommet is the most common but many colors are out there.

 

this could be the answer to my truck problem, the duraspark module, that is. lemme know what happens

 

Don;t over look the possiblility of a broken or lost contact wire associated with the ignition.
One popular spot for them breaking down was where that go into the back of the plug-in connectors (on the distributor to engine harness especially).
These wires get brittle with age and can deteriorate anywhere in the harness.

 

The module and wires inside the distributor also go bad. These poor trucks are getting WAY old...

 

it sounds alot like my module but when it dies on the road it starts right back up. It could still be anything because all of my ignition wires and parts look original and the wire are falling apart.

 

FWIW, I changed the original ignition module in my 79F100 after I bought it 7 years and 255,000 miles ago. The original one was working fine, but I replaced it with a Standard Brands 'Blue Streak' module. At the time it cost me 50 bucks plus tax. It has yet to let me down. I kept the original FoMoCo module as a spare, but as of yet it hasn't been needed.

 

Also inspect the wires to the pickup coil. It's inside the distributer. It has two small wires that get brittle and crack - when you accelerate the pickup coil moves causing the wires to separate and engine dies. The the coil moves back to original position and the wires connect again.

Marty