Starter won't engage after shutting off.

[sooptime]

If the problem is on warm engine then in my opinion You have to "fix" starter.

You have to take out starter and clean and slightly bend 3 connectors, which are responsible for connect starter with engine neutral (-).
In time those connectors looses proper contact - especially after engine is litle warm up

This photo (shamelessly snatch from other forum) says all:

Thanks. I will check that too. Not into breaking down again. It happened when my alternator went and battery died. Good times.