I posted this problem on CCOT's forum earlier this week. Although I recieved good replies, none of them has helped find the problem:( . I hope someone on this board can help.
I have recently had problems with the starter in my '72 FJ40. Sometimes when I turn the key I get nothing. The AMP gauge drops showing a discharge (like the starter is getting power), but the starter doesn't turn. No clicking sound from the solenoid either. I can open the hood and short across the terminals on the starter and the truck will start. I have already replaced the starter switch, but no change. I suspected the starter or solenoid going bad. I replaced the starter with a reman from NAPA. When I turn the key to "start" the starter turns fine. When I return the key to "run" the starter continues to turn. I removed that new starter and retuned it to NAPA thinking it was defective. They put it on their tester and it worked fine. They tested my old one and it too tested fine. I tried a different new one and it did the same thing. What gives? Could the starter gear be getting jammed into the flywheel therefore not allowing it to return properly? Would a shim help?

Thanks in advance.

Intermittent starter problems are either bad brushes or bad solenoid. The new starter is also bad because it won't retract either due to a weak/bad return spring or the tooth engagement is too tight. I would have them replace the rebuilt starter with a new one.