Need some ideas where to look for starter issue

[Eclipse99fwb]

Ok, i have had a intermittent issue with my accord for 3 years ive owned it. It is a 98 accord ex sedan with f23a1 manual. The issue i have is once in awhile i go to start and the starter spins but doesnt extend the gear arm. I will let it sit for a second and it will start (may take a try or two).
I tested the starter and verified the arm was spinning slow and occasionally not extend. So i replaced with a denso. Worked for about 2 months than problem came back. Thought i got a bad starter so replaced again with a denso. Same thing happened.
Recently i decided to tackle this issue again since work has been slow. I tested the starter but found no issue. I replaced for the 3rd time with a durlast this time seemed to work fine for a week till this same occasional spinning but no arm extension.
Ok so now that you have the background here is what i have checked and replaced:
-Ignition switch (was having symptoms during this time, fixed those issues
-battery (needed it)
I haved checked the power wire (not issue 12 volts)
starter signal (good on signal and wiring is ok)
Both battery terminals are good and free of corrosion.
No shim installed at mounting point of starter.
Flywheel is not missing teeth (ive replaced my clutch twice so i inspected it up close. I also turned the motor during this last replacement and watched it this last time.

Any ideas would help. I am stumped (i cant imagine ive gotten 3 bad starters.
I am not dumb by any means and know my way around a car ive spent the last 6 years turning a wrench for a living. I have also had 5 different mechanics look at it (2 were master techs with over 62 years combined experience). They all said the starter is the issue, i test it and verify occasional yhe arm would barely extend or spin slow, except this last time.
I really would appreciate it, i can live with it but it sucks having this issue as ive taking very good care of this accord and im trying to keep this as the wife is tired of me buying accords lol. Ive had 4 a 86, 91, 92 and now the 98.

 

[Adhmuz]

Are these units re-manufactured or brand new?

When you say you're testing them are you testing them in the car or on a bench?

Have you replaced the starter relay yet?

 

[Eclipse99fwb]

Two were remanufactured, my current one is new. I bench tested all of them. I havent checked the starter relay due to it being very intermittent. I did however replaced the end terminal on my control wire. I noticed it would fit snug but had a little play and if wiggled the wire i could recreate the problem. So far since doing this it has worked perfect, but so did my other ones for a month or two. I may swap out my relay this weekend just to make sure. Thanks for the help, i will keep this updated incase anyone else runs into this problem.

 

[Adhmuz]

Hopefully the new one you have doesn't have the same problem, a re-manufactured unit might test good on a bench or when getting QC'd at the factory, however the solenoid will intermittently not trigger or fail when actually being used. Who knows if that was the original problem it had when the original owner pulled it from the car, I can say that was certainly the case with the ones I've replaced, solenoid wouldn't fire when hot, worked when cold. Don't forget the potential age of these starters, IMO your just better off getting a new one if you plan on keeping the car.

All that being said, I would still consider replacing the starter relay, they aren't expensive and you can rule it out for next time.

 

[Up42long3]

It may be corrosion of the ground connection where it bolts to the engine/tranny. On my daughters V6 it bolted to a bracket which was then bolted to the tranny via a long bolt. Also the wire itself was badly corroded. We took this bracket off. Cleaned all mating surfaces as well as the undersides of the bolts and threads. Cleaned up wiring corrosion. Reinstalled. No issues since.