Igntion help

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Sep 10, 2016 | 04:17 PM

ford5o

Thread Starter

Junior User

Joined: Dec 2008

Posts: 51

Likes: 0

Igntion help

My truck just shuts off. Ok, the whole story, its a 79 f150 frame and motor( 351m). The cab was swaped over to a rust free 77 cab. The truck ran great for about 2 years and still does, but now it just shuts off. Driving along everything is good then it just shuts down, like if the coil wire was just pulled off the distributor. Limp it off the road and check start solenoid, power to the coil ( yes the coil is getting low voltage in the run setting. Its supposed to, like 9ish volts). Everything checks good and truck starts right up. Drive home and its fine. Next day ,same deal, driving along and shuts off. The motor shuts down with key on, never turn key off, just crank and starts right up. Been doing that for a week. Replaced igntion module, coil, main ground to the block. Now sometimes after it shuts down the igntion switch will give a puff of smoke when restarting, but it starts right up and runs good. My next thing is the ignition switch. I see the ground tab on the switch is soldered to the metal part of switch. With switch not mounted in the dash the switch is not grounded ( the metal part of the switch that is seen). I do have ground coming into the switch thru a wire tho. Any help?

Sep 10, 2016 | 05:35 PM

scottscott

Fleet Mechanic

Joined: Dec 2007

Posts: 1,502

Likes: 339

From: Wildwood Pa

Replace the pickup coil in the distributor.

Some good testing info in this thread: https://www.ford-trucks.com/forums/1...ark-issue.html

More here: https://www.ford-trucks.com/forums/1...ckup-coil.html

Sep 11, 2016 | 12:33 AM

PapaBearYuma

Cargo Master

Joined: Nov 2011

Posts: 3,354

Likes: 48

From: Great American SouthWest

X2 on the pickup coil...