Help! Won't Stay Running

[Groundkrawler]

40 hasn't been started in about a month. Went out to start it and it fires but as soon as I release key it stalls. If I hold key in start position it runs fine. It has always started the first or second time and run fine. Any help is greatly appreciated. Thanks!

 

[bsmith123]

start vs run

you are getting power for start but not run, you need to trace back and see why you have no power with the key in the run position

of course in an emergency or if you just need to run it for a while run a wire from your battery to your coil and she will stay running when you come out of start

 

[Groundkrawler]

Not an electrical guy at all. I've had the 40 since November and have been spoiled, no problems at all. Where do I start? Thanks for the help.

 

[edwjmcgrath]

The one thing that comes to mind based on your symptoms is the coil bypass resistor.
If it was broken (or had a bad connection) then your engine would run in the START but not the RUN position.
To check this out, disconnect the two wires that come to the positive terminal on your coil. One should be energized (measure 12v) when in START (this comes from the starter), the other will be energized in RUN.

Another way to test this is, as suggested above, run a short jumper from the battery to the positive terminal on the battery to the positive terminal on the coil. If it runs then there is an issue with the resistor or the wiring to it.

 

[bsmith123]

ignition

http://www.globalsoftware-inc.com/coolerman/fj40/schematics/FJ40/1976FJ40/Haynes1976FJ40Page1.jpg


Check out the BY wire shown between the ign switch and the coil/igniter

 

[Groundkrawler]

I will give it shot. Connections dont look too clean so I will start there. I will also put a meter on them and check voltage in each position. Thanks for the help and the diagram!

 

[Groundkrawler]

Ok...ran the jumper and it fired right up. Disconnected the jumper, cleaned up the connections and still nothing. Checked the resistance on the resistor and ballast and both measured 2.5 ohms so they appear to be fine. Next question...when I put the key in the run position where should I take a voltage reading? I am starting to think it under the dash and not the hood. Thanks again!

 

[Michael Hanson]

Do you have another ign. switch you can try in it? MIke

 

[edwjmcgrath]

With the positive wire to the coil disconnected, you should have 12v with the ignition on.
You can measure it at the connector at coil, at the other end of the resistor, and then check both ends of the "engine" fuse. If you don't have 12v at the engine fuse, it's probably the ignition switch.

 

[Groundkrawler]

Gone for a couple of days. Don't have another switch so I will take some voltage readings and see what happens. Thanks to all for the help!