I am refurbishing a 1977 F-150 for my dad and have run into a few problems I hope someone can help with. The truck starts fine when cold, but if I shut it off and try to recrank it when it is warm, the ignition key won't activate the starter. I can use a remote starter with no problem, but the key refuses to work until it has cooled off. When I do use the remote starter to crank it, it starts and then dies immediately, almost like it is vapor locked. It has a new carb and fuel pump, with new tanks as well. Has anyone encountered this before? I am probably missing somethign stupid, but until I find it I'm getting really pissed off. It runs purfectly until I try to restart it. Help, please, before I get fed up and try to turn it into an insurance scam.

 

Might be the key switch. You could try running a hot wire from the battery to the "+" side of the coil when you use the remote starter. If it stays running it will involve the resistor wire to the coil. It reduces voltage after the starter is released to protect the coil.

Harold

 

When the starter solenoid is engaged and starter is spinning the engine, the starter soleniod is sending full voltage to the coil + side from the small terminal (sometimes labeled "I") closest to the large terminal going to the starter on the solenoid. This is the reason why the engine does run as long as the starter is running when you remote start it. Do you have the key "on" when you remote start it? It needs to be in order for it to keep running unless you "hotwire" it as beartracks suggested. You might want to get an electrical tester to see where you are/are not getting power to. A cheap light-bulb style will work fine for this problem. Your tester light should glow somewhat dim when the key is on and you check the + side of the coil. If you check it while cranking, the light should be brighter.

If you are remote-starting it by running a jumper wire from the battery + to the small terminal (sometimes labeled "S") closest to the large terminal going to the battery on the solenoid, then the solenoid is working fine. Look for a wire problem between the "S" terminal and the switch or the switch itself.

If you have been remote starting the engine by running a "hot" cable from battery directly to the starter, and the starting method in the above paragraph does not work, and your battery cables are clean & tight, then try a new starter solenoid.

Either way, the problems you describe are probably not caused by vaporlock. Many electrical components are affected by heat also.

 

I think that my key switch is the problem based on what you said. Thanks for the input, I will change it out today and try again.

 

 

Ccoffin,
I,ve had a similiar problem about twenty years ago with my 76 F100. Your symptom is describing a Dura Spark failure. the ignition box located on the driver side fender well tells the ignition to send 12V to the coil during start up and cuts the voltage back to 7.5V? or 9V? during normal Ops. You box sounds like its not getting the correct signal to the ignition. The starter should still turn though. Is the vehicle flooding? It would, unless there was a vapor lock? Try spraying Carb cleaner down the carb in this situation to see if it is starving or not. I bet it's getting all the fuel it needs. Those spark boxes are cheap and I always keep one with me. My existing one hasn't had any goo in it for ten years and still works fine.
Good Luck, Have Fun,
KingFisher

 

The carb is getting fuel, and I couldn't replicate the problem yesterday when I was ready to chase it down. Figures... I guess I will replace the key switch and the spark box and see it that works. This truck is for my dad and I want it to be right when I give it to him, so an MSD ignition may be in order anyway. Jacobs would be nice, but not for the money. Thanks for the help.

Chris