240 Tried to start when hot, no crank, nuttin

1986 245 DL Auto, nearly stock everything, new coil installed after a problem staying running once hot...

We did a number of errands when it was 105+, finally wouldn't start. No cranking, nothing. Came back later (three days), and it started right up. Has not missed a beat since.

I was thinking it was most likely the ignition switch, but now I am not so sure... I searched for info on a cranking relay and couldn't find any... Is there such a thing?

Anything else this might be? Only other possible symptoms are low MPG (21.5), runs fine otherwise.

My '91 does this too, it was getting worse and worse till I finally replaced the starter with a cheap generic, the problem went away for a while, until a long drive in the desert, then it did the same thing. Let it cool down for an hour, then it started right up.

Happened again after sitting in traffic on a 90* day, I let it cool down for 30 minutes or so and it fired right up.

It'll cool faster if you (carefully) remove the coolant reservoir cap.

It's not common for a pre-'87 starter to fail though, so it might be something else

Hmm. Did the starter act any differently? Whine or groan, or crank more slowly, you know...?

Mine didn't crank slowly or make weird noises; towards the end, there was more and more of a delay between when I had the ignition switch in the start position (III) and when the starter fired.

Before replacing my starter, I swapped batteries between my cars, replaced the ignition switch, and replaced the neutral safety switch.

There is not a starter relay that I know of.

SOMEtimes, it does seem like there is under a half-second delay of when I hit the starter, and when it begins to crank... No change in the noise it makes though.

I think I will go ahead and install that $100 ignition switch since I already bought it. If it happens again, a starter it must be.

When it won't start do the following-
Check voltage at the battery.
Check voltage at the starter.
Check for solenoid signal from the key.

Have your battery load tested. It may be failing when hot.
Check your grounds.

It may be the starter, but that's not the only thing it could be.

How old is the starter? Old ones can be full of crap and/or have dirty commutators. Do badvlvo's checks; current draw should be around 9-9.5 volts when cranking.

Thanks, will do...

Only thing I have done before now was check the resistance of the main ground, it was -very- low, less than 1 Ohm IIRC. Will check the rest, esp. the battery load.

Mine did this, and was a starter issue. We had 3 starters fail on 2 240s and a 140 at my mom's within 3 weeks if each other...'71, '76, and '83.

Do you hear the starter clunk when you turn the key?