1993 Toyota truck, 4x4, v6, manual. When turning the key over to start the truck receive a single click and the engine does not turn over. This is an intermittment problem - if I continue to turn the key off/on, the motor will eventually turn over and start. Does this regardless if I depress the clutch or press the no-clutch start button. Is worse at first start in the morning. After warming it does not happen as much. Replaced battery thinking it was a weak battery, but no improvement. It is getting worse with time. Any thoughts would be appreciated. Starter? starter relay?

 

I would have to say its the starter. If you can hear the starter spinning but no turning of the engine it may be the starter sylinoid. Otherwise, the starter took a crap on ya.
Thats just what I think, may want to see what others say.

 

search for starter contacts, I think a lot of guys had the same issue, and found you can repair the contacts in the starter.

 

The copper contacts inside the starter solenoid are prone to wear, easy and inexpensive to replace:
- http://www.4crawler.com/4x4/CheapTricks/Starter.shtml