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So I decided to start working on the old project again. I am new to the site and am stumped hopefully someone can help. I have 79 Bronco with a 351M. It starts up, idles and the engine runs great. When it starts to get hot I have to constantly give it gas or it will kill. Someone told me it might be the distributor, any ideas? Thanks
 

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sounds like you might be getting vapor lock.

check the metal line from the pump to the carb and make sure it is not touching the block or anything else.
 

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How hot is hot?

Another thing it could be is a cracked coil. Sometimes they work fine until the casing heats up and the crack gets wider. Start it up at night, and look at the coil to see if it is arking.
 

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did you check the choke? it did kinda the samething on mine.
my elctric choke. ya know the one i never hooked up. keept closing. cousing pretty much the same problem.
 

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If its vapor lock, it will eventually run out of fuel and die.

If the coil is going south, it should be mis-firing, when you gas it.

I'm guessing a vacuum leak. Metal expands as it warms up, opening up a crack or a void in a gasket.

To eliminate the coil, let it warm up, and die. Then IMMEDIATELY hook up a good coil and restart. If the symptoms disappear, then the old coil is bad.


Put a clear fuel filter on the fuel line, and see if it stays full. That will tell you if its vapor locking/and or weak fuel pump.

Good luck tracking the problem down.:beer
 

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The ignition control module will do this as well. 5" square box on the drivers fender well with 2 connectors..;)
 

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I had the same problem with my 400. turns out the fuel tank was so rusty it filled the inside of my edelbrock carb with a super fine rust. looked like texas red dirt. it would crank and run great for about 20 minutes. then when it got to op temp it would sputter out and die.
 

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Sounds like it could be a number of different things, as experienced by these guys. Start with the easiest & cheapest possibilities & work up.

1. choke operation,
2. vapor lock,
3. fuel filter,
4. coil,
5. ignition module,
6. fuel tank (fuel filter should catch this stuff for awhile though, until it plugs up)
 

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Sounds like it could be a number of different things, as experienced by these guys. Start with the easiest & cheapest possibilities & work up.

1. choke operation,
2. vapor lock,
3. fuel filter,
4. coil,
5. ignition module,
6. fuel tank (fuel filter should catch this stuff for awhile though, until it plugs up)
I agree, NUMBER 1 most likely is your problem, let it warm up, pull your air cleaner off and make sure that choke is fully open if it is then, next step is a semi-severe vacuum leak, or a carb severly out of adjustment. Giving an ignition problem throttle will not keep them running. Also if you can give it gas and it will stay running tells me it's probably not a fuel delivery problem.(unless you have to pump the shit out of it to keep it running-but, sounds mostly to me an idle problem)
 
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