Hi, I'm Daniel. Welcome to Just Answer. You cannot ask to many questions. Only positive feedback needed while in info request. Lets get started.
I believe your starter is going bad if your wires and cables and grounds are good.
clean the cables and wires to starter and alternator. and neg battery post to ground on vehicle.
I see this alot.
and starter may be just fine.
I had cleaned and re-tightened all the underhood ground wires and cables earlier (there are only a handful), so I don't think it is on the ground side of things. When I installed the starter last fall, the cable connections to the starter did not appear particularly dirt or corroded. This car does not get driven in the snow and salt season.
One thing I did not do when I installed the starter last fall, was use the shim plate. Is it possible for the pinion on the starter to fit too tightly into the ring gear?
Ok somewhere in the circuit there is a path to narrow for amps to get through. have you checked battery? if it has a dead cell it will do this whenhot.
it can read 12 volts but be bad.
I have not yet checked the battery - however, the car would not crank when jumped to another car. So wouldn't that indicate that the battery is not the issue?
Kinda. I sure hope the new starter isnt bad it will have us running all over the place so go to auto parts shop and test battery when cranking. you may have to let it cool down but better than taking it out of the car. What is going to happen if everything I have asked you to check out is ok the ignition switch needs to be replaced. and wires and connection need to be inspected of course. but if a relay is dirty or you have corrosion its going to do this and relay connection may even need replacing. please dont forget or ignore the neg battery post cable to the vehicle ground. This is the most popular reason for this issue and most missed.
The battery ground to the front of the engine block was one of the cables I cleaned and re-tightened today. And it seemed clean on both ends. Tough to get to the engine ground connection, behind the alternator accessory drive frame! I don't see how the ignition switch could cause this sort of malfunction - when hot, the engine "tries" to turn over, but only goes a partial revolution, not enough to get the engine to fire.
So, so far, it still seems to me that the most likely culprit is the new-last-fall starter. So I will swap it out if I can't think of any easier alternatives. You mention starter relay. Hadn't thought of that. I don't have my shop manual in front of me.... Does this car have a starter relay? If so, I wonder where it is....
buy now the wires and connection to ignition switch would have a burnt smell. the starter relay can also have a voltage drop from relay to starter. let me get you location ok.
No burnt-insulation smells as yet.
click here for diagram it runs through the theft deterent relay if you have it.
Hmmmmmm...... But there is a direct connection from the battery to the starter. We may have gone as far as we can tonight, until I can try some other things. (which might take a couple of days) If I learn more or have other questions, how do I contact you?
click here and I will send url after accept so you can get back to me. check fuses and fuse connections. make sure there isnt any corrosion under fuse box
By "after accept" do you mean choosing one of the frown-to-smile faces?
They change it all the time. But I believe thats right.
OK, will do, have a good evening.