Author Topic: Won't start when hot  (Read 1512 times)

Offline Yoshi

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Won't start when hot
« on: October 27, 2020, 12:38:23 PM »
I have a 1980 Chevy K10 short box with a 350. When I drive my truck for extended periods of time and then turn it off, it will not start up again for about 30 minutes, as if it has to cool down before it starts. I do not have this problem when I drive my truck locally for 5 to 10 minutes. During the times when it won't start, all the dash lights come on all the electrical works but there is no response in the starting system no clicking no nothing. Can anyone tell me what the problem is with my truck. Thanks.

Offline fiddler

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Re: Won't start when hot
« Reply #1 on: October 27, 2020, 05:39:59 PM »
First,  check your battery connections.  Take the cables off and wire brush the cable ends and battery connections.  Be sure to clean the inside of the cable connections, then reinstall and see if that helps.  Those connections have made fools of us all over the years.   I have a 1974 so I only have a diagram for that year.  If they are pretty much the same....There is a purple wire going from the ignition switch in the dash via some connection blocks to the starter solenoid.  I would get a meter or test light on the purple wire, (red lead of meter or test light to the purple wire, black lead to a good ground.)  Verify that the meter sees 12 volts when you engage the starter.  Then let it heat up to where it won't start.  If you still have 12 volts at the starter solenoid then your problem will be the starter or solenoid, and you probably can't get just the solenoid so you will need to replace the starter.  If you don't see 12 volts you will need to check the connections through the connection points.   But BE SURE TO CHECK/CLEAN THE BATTERY CONNECTIONS.
Ricky

Offline JohnnyPopper

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Re: Won't start when hot
« Reply #2 on: October 28, 2020, 09:43:54 PM »
Funny how electrons lose their collective minds when overheated! 

The fiddler is correct, if you have poor connections you will lose the current you need to produce the work required to move the metal.

Having suffered with similar conditions, I recommend that you check the components around the starter relative to the very HOT exhaust manifold.

There may be connections at the starter that have been corroded, are electromagnetically compromised, or just gunky that when HOT,  confuse the path of much needed electrons.

Clean with electronic solvent, tighten, and make sure you have solid wiring.   

Some models need a heat shield between them. I think they all should have, but, GM had to turn a profit, right?
1957 Apache 3100 235 Inline 6, 3 on the tree
1973 C-20, 3+3 454 4BBL TH400  Water Injection
1978 K-10, 350 4BBL TH350 NP203 M.M. Part time Kit/Hubs
1980 C-10 under construction

Offline Yoshi

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Re: Won't start when hot
« Reply #3 on: November 02, 2020, 01:58:31 PM »
Ok fiddler and JonnyPopper, I'll make time, check the connections all the way to solenoid, then let you guys know how it goes.  Thanks for helping.