I had reported on an intermittent starter problem and finally have a solution to share with you.
This was occurring on a rebuilt starter that had been in the car for 4 years. Symptom - turn key, hear click, turn key a number of times and finally it starts.
The garage first changed the contacts in the starter as they found them pitted. That fixed the problem for 3 weeks - then it returned.
They pulled the starter and commented that the replacement contacts were getting pitted as well - and proceeded to change the solenoid.
No change - still intermittent no start.
Next they replaced the starter with a recently completely rebuilt one. Now I would get no click and no start!! I would have to hold the key on 'start' while someone whacked the starter. Very impressive!! - good thing I'm past the age of 'dating'.
Back again to the garage they pull the replacement starter, examine it - it is perfect. Put it back - same problem.
Finally my 'regular' garage (they are getting too popular to be able to get into them so I had to go somewhere else) takes a look at it and suggests the wire from the relay is possibly corroded - causing resistance on load - which leads to starter contact pitting and intermittent starts. We replace the wire and BINGO - problem solved.