1979 F150
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1979 F150
I have a 1979 F150 with the V8 400 in it full time 4x4. It's been in the family since 1979. It has always started and never had any issues. Until about 8 months ago I was driving home and it died. The engine just cut off. I parked it and tried to start it. It would turn over and start in start mode but when key was released to run mode would die. Every once in a while it would start but that was rare. I put a new timing chain and gears on the old was a link loose so I thought that would do it...no. I changed the starter solenoid, the ECM, the ignition coil, the ignition switch, and also put a new distributor in. I still get the same results, it cranks and starts in start mode but won't stay running. I have spark and I have fuel pouring in the carb.
Postmaster
Joined: Mar 2011
Posts: 2,698
Likes: 7
From: Taxachusetts
Too bad you threw all those dollars at it just chasing spooks.
It sounds like the resistor wire gave up the ghost.
Do you have a mutimeter? With the key in RUN check the voltage at the + side of the coil. Should have 5 - 7 VDC.
We'll go from there when you find out what you have or (more likely) have not.
It sounds like the resistor wire gave up the ghost.
Do you have a mutimeter? With the key in RUN check the voltage at the + side of the coil. Should have 5 - 7 VDC.
We'll go from there when you find out what you have or (more likely) have not.
Postmaster
Joined: Mar 2011
Posts: 2,698
Likes: 7
From: Taxachusetts
I was off on the 5-7 VDC. Should have been 6-9. At any rate, from your readings, your resistor wire is toast and needs replacing.
A few different schools of thought here. You can trace/replace the wire from the ignition switch (main wiring harness under the dash) or connect a new 12ga wire with a 1 - 1.5 ohm ballast resistor in it.
Below (courtesy of Number Dummy) is the particulars on the replacement wire.
D7AZ-12250-A .. Resistor Wire-Ignition Coil (Motorcraft DY-213).
49" long / Color coded red with green stripes / 1.30-1.40 ohms resistance / #16 gauge wire.
1977/91 F100/350, Bronco & Econoline.
Bill // Retired Ford Parts Manager // SoCal Chapter member // Part Number Research: 1928/2001 FoMoCo vehicles.
A few different schools of thought here. You can trace/replace the wire from the ignition switch (main wiring harness under the dash) or connect a new 12ga wire with a 1 - 1.5 ohm ballast resistor in it.
Below (courtesy of Number Dummy) is the particulars on the replacement wire.
D7AZ-12250-A .. Resistor Wire-Ignition Coil (Motorcraft DY-213).
49" long / Color coded red with green stripes / 1.30-1.40 ohms resistance / #16 gauge wire.
1977/91 F100/350, Bronco & Econoline.
Bill // Retired Ford Parts Manager // SoCal Chapter member // Part Number Research: 1928/2001 FoMoCo vehicles.
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