We just bought a Ford 1970 3/4 ton with a 390. Did a carb rebuild, replaced ignition coil and replaced battery.

Its starting up, then after a few seconds... dies. Sometimes it lasts a little longer about 10 seconds or so. Also, sometimes if the gas pedal is pumped it immediately dies.

Any help would be great.

 

I suspect a fuel delivery issue. I would start by checking and/or replacing any bad fuel filters. Test for a weak fuel pump. Verify carb float level. Welcome to FTE!

 

Already checked the fuel filters, fixed the carb float levels and after doing that it cranks but wont start for more than a second

 

Could be you fuel pump or a plugged line, if you never had it running in the first place have someone turn the distrubuter when your cranking it and see what happens, if its already properly timed plug your vaccume line that goes to the distrubuter with a golf tee.. it could be something in your carb..

 

Could be the ign. switch if you have old round style terminals, they do go bad. When mine when soon as I took my hand off the key it would quit.

 

already checked fuel pump and no clogs in teh lines, we drove it home when we got it a few days ago, but it kept trying to stall. took carb off and rebuilt it i'll give that a try in the morning with the distributer. were running a compression test and checking the timing in the morning

 

Might want to check the primary wire from the dist. to coil. Mine was old and had a crack in the wire that was grounding out on the engine.

 

oops didn't read that last one

 

PluS.. may want to check for checked rubber fuel lines that can suck air and fuel pump Won't pull any gas to the carb...Yeah those ign switch with round contacts get hot and over heat the wires so ez to see on the back of the switch plug..orich

 

Yeap they do get hot but with mine I was losing contact. Don't know how but a couple of round studs were loose in the female connectors.

If I remember right you can run a wire from the + side of battery to + side of coil to bypass ign. Just make sure truck is in park and emergency brake is on.

 

Got it running and now it died again.

Replaced fuel filter, points and condensor and then it was running great. Sounded excellent. Took it for a few tests drives, fantastic. Hubby then went to go pick up something from the store with it and test it out at hwy speeds... partway back on the freeway and .... dead. cranks but wont start

 

Try hot wiring it to get it home as OP says Or any time it fails to start as a test too by pass any poor wiring or Ign. switch....orich

 

FIXED! The points fell out of adjustment, screw tightened and running excellent again. Thanks for all the help!!!