Hi guys,

I have a 1968 F-250 with a 390 only mods on the engine that I have done and know about are an edelbrock performer intake and 4 barrel carb and a Pertronix flame thrower coil.

Now my problem , last Tuesday I left my house and drove about 3 miles and had just downshifted to 3rd as was about to go to 2nd when there was the loudest backfire I've ever heard. It doesn't normally backfire . It sounded like someone shot a gun off in the cab . I pulled into a parking lot a 50 ft away and it died , mabey from me letting off the accelerator . It would not start back up I could crank and crank all day but it would not fire . My dad pulled me home and I didn't have a chance to take a look till later that night . I thought probably fuel issue so I poped the line off and there was plenty of fuel coming out when I cranked so I put it back on and it started right back up and ran great . On Thursday I started putting a block heater on so it didn't run for a few days .today I started it up and it ran great again . It ran for about 5min and then almost shut off , everything went quite for a split second then came right back to normal so I let it keep running and about 2-3 minutes later it shut off and did same thing as Tuesday . it wouldn't start and there was plenty of fuel getting to carb.

Any ideas what might be the problem ? Thanks !

 

This sounds like an ignition issue possibly a lose connection that is interrupting power to the ignition system.

 

I'd open the dizzy cap an checked that it's all ok no wires rubbing the inside the housing, or a loose wire in their.

Check all wires going to & from the coil.

If all good it could be the ign-switch/plug problems. Use a volt meter or test light when the truck fails to start.

Orich

 

Thanks for the reply Matthew and Orich

I'm heading out to work on it right now . I'll check wiring on ignition and distributor and let u know what I find .

Thanks !

 

I checked my coil harness and sure enough there was a break in the wire. Thanks guys for your replies , saved me a ton of time

 

Thank you for the update:
That's what we like when helping someone. They do what we think where the problem is. Then you follow through as what we listed...Then bing~0 found & fixed..

Orich