Chevy & GMC Vans

I recently bought an S-10 truck with 4.3 & 5 speed trans it runs great but after it runs and gets to operating temperature
and I shut it off then try to start it, it acts as if the battery is close to dead. after it cools it will start again. I have checked the battery and the alternator with a multimeter and all is fine. The starter looks new but who knows as I just bought it. Before I swap out the starter is there anything else I should try?

from my past experiences a worn out starter motor will do exactly that. cant say for certain it aint something else either though.

Heat from a header tube will adversely effect the solenoid and will cause a hard start, you can install a remote solenoid to correct this problem.
A poor battery connection can also play havoc. Check your "big three" battery connections.

Peter

can a battery show 12 volts on a multimeter and yet have a bad cell? hence volts be good but amps be low?

Put the multi meter on and check the voltage, then check with the with the lights on. I bet it will be 11v or less. It should barely drop with the lights. A no load test is almost worthless.

The only way you can have normal volts (12-14) and low amps is a high resistance connection. My guess, you have a bad or loose cable or connection somewhere, or your starter is bad if your battery tests OK.

I think I figured out the problem, The pickup coil inside of the distributor may be bad as I was told by a GM tech that they get weak and then they get heat soaked every time it is run so it causes a resistance in the distributor.