Hot Start

[390xlt]

So my truck has developed a fun new quirk; it doesn't like to start once it's reached operating temperature. When it's cold, it starts just fine; I barely touch the key and it fires right up, but when it's warm, I turn the key and it will turn over normally a couple of times, then it starts turning much slower until finally it kills the battery and just won't turn anymore. That process takes no more than a few seconds. If I get a jump, it will start, but it takes a while. Once it's running, it runs fine.
I can't pinpoint exactly when it started happening, but here's a list of things that have been done fairly recently:
New battery
New starter
New coil
New plugs and wires
New condenser
I've checked the connections at the battery, solenoid, starter, and block, and everything's tight. I've also confirmed that there's fuel in the bowl.
My only other guess is that maybe the starter is getting too hot, but I've got manifolds and the right pipe doesn't run particularly close to it. I'm stumped. What should I check next?

[Ranchero50]

When it acts up get out and fell all of the wiring / connections between the battery and starter to ground to battery. Something most likely will be hot indicating resistance. Then check the battery voltage after sitting overnight. If low, charge it and check the next day. If still low, pop the terminal and charge it again followed by a night of rest and checking the voltage again. If still low, condemn the battery. If that turns up nothing, swap the starter out for another. Rebuilds aren't what they used to be.

[390xlt]

I haven't driven it since Saturday, so I'll check the battery voltage when I get home today. If it's okay, I'll warm it up and try to start it again and see what happens and report back.
Thanks!

[Jacksdad]

I've been plagued by this since I got mine. I'm on my third starter - now with a heat shield - and new (bigger) cables. I've heard that the fix is either a quality mini starter, or an original factory starter rebuilt by someone who knows what they're doing.

[Ohiotinkerer]

Had my starter rebuilt by our local NAPA store and between that and a 1 inch phenolic spacer between the carb and intake I have eliminated all hot start problems........nothing more annoying than it not turning over AND having the heat of the engine boil gas out of it .......

[390xlt]

Battery voltage is good (12.68v) when cold. Drove around a little last night to get it nice and warm and, sure enough, same problem when I tried to start it up again. Battery cables and starter cable were fairly warm, but all about the same temperature as each other and no hotter than I would expect them to be having sat under the hood next to a hot engine. Is it safe to go ahead and assume the starter is the problem here, or is there anything else I should test?

[1972hiboy]

when the problem is happening,I would do a amp draw test on the starter and have a multimeter on the battery to see what its doing too.

[390xlt]

Multimeter on the battery is no problem. How do I do an amp draw test?

[1972hiboy]

Doing an amp draw test does require a specialty tool. I have seen them for sale at Sears even. its a multimeter but it will have a wand attachment and you clamp it over the power cable going down to the starter. When you crank it you wanna watch the amperage flow. For a small starter like that I wanna say you dont want to see the starter pulling more than 300 amps? I am used to the big diesel ones that pull alot more so hopefully somebody will chime in if i am off base. But essentially if you have good supply power and the starter rotates slowly and demands high amperage its mostly likely a defective starter. Ill see if I can find a pic of the tool i have in mind.

[390xlt]

Haven't had a chance to put one of those fancy multimeters on it yet, but I did take it out to run some errands this weekend. As I expected, it started up just fine in the morning. I put about 15 miles on it and then it sat for a couple of hours. It took a little longer than I'd like for it to start after that, but it did start. Put another 5-10 miles on it, then it sat for about 20 minutes. That time (as I suspected it might), it wouldn't start. I then let it sit long enough to run into a store and grab a bottle of water. I came out and poured it on the starter as best I could, and that cooled it down enough to fire up for me. I don't love the idea of dumping water on electrical equipment, so I still need to find a permanent solution (a new starter, I'm guessing), but there is some relief in confirming what the problem is.