Truck won't turn off
 

Hey guys recently I have been having issues with my 1970k10 not shutting off whenever turn the key to the off position. It only does when the trucks been running for 10+ minutes and it only started doing a few weeks ago and I haven't done anything to the ignition or distributor. Does anyone have any ideas? Thanks
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Re: Truck won't turn off
 

How do you get it to shut off, if you shut it off in gear if its an auto will it shut off? Could of developed a vacuum leak and its "dieseling" IE running off the heat from the exhaust valve. When it doesn't turn off, does it run smooth or kinda rougher than when the key is on?

Re: Truck won't turn off
 

bring your idle down, sounds like you're describing dieseling..

Re: Truck won't turn off
 

See how good our trucks run? They never want to shut-off :lol:

If it's not deiseling, your ignition switch may need replaced.

Re: Truck won't turn off
 

Did these trucks ever have the "anti-dieseling" switch on the throttle linkage?

Another thought: could be deposits of carbon in the combustion chamber and on the valve heads. They get hot, then they glow, and if there's a bit too much idle throttle, they detonate the mixture and the engine keeps firing, usually really unevenly.

Re: Truck won't turn off
 

It's a manual transmission and usually what I have to do it get out of the truck and undo the positive battery cable but every once in a while if I turn the lights on it will shut off when the key is off and it's still running and it runs the same whether the key is in the on or off position..it's got me pretty confused
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Haha I'm saying right
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Re: Truck won't turn off
 

Easy to check if it's dieseling or running.
If you can drive it normally with the key off then it's not diesiling.

Okay I'll give it a try
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Re: Truck won't turn off
 

that doesn't sound like dieseling...

Re: Truck won't turn off
 

Short from main lug to points bypass wire at starter?

HEI plugged into wrong spot on fusebox (I know you said no changes, but something changed somewhere)?

Re: Truck won't turn off
 

Disconnect the alternator wires-start engine see if it shuts off! Maybe open diod in alternator!

Re: Truck won't turn off
 

Mine did the same thing once and it was tbe alternator back feeding power. Try removing the alternator plug and if it shuts off you need a new alternator. Just buy a 1 wire alternator cleaner anx easier

Re: Truck won't turn off
 

http://www.madelectrical.com/electri...hreewire.shtml read this before you go to a 1 wire...

Re: Truck won't turn off
 

hunter1123--Have YOU figured out why your engine wont shut off! Let us know how you are doing---might help someone else! GOOD LUCK

Re: Truck won't turn off
 

Have you found the problem? The fix!?

Re: Truck won't turn off
 

Yes I have the alternator was not wired correctly since there is not an idiot light on the truck the alternator would back feed power into the ignition/distributor keeping the truck running, thankfully a $15 alternator harness with a in line diode solved he problem, thank you for following up!

Re: Truck won't turn off
 

thanks for the update