I have been reading these threads for a few weeks now trying to learn all I can. I just recently bought a 92 4runner with the 3.0 and I am trying to get it up to shape.
I am going to Korea for a year and needed a reliable back up vehicle for the wife I am leaving in the states. So far I have done plugs, wires, and caps. Old plugs were gapped anywhere from .36 to .72 the idle was horrible and it was overfilled by a quart of oil.
I got the rear window to work by cleaning the mechanisms and smearing axle grease all over the gears.
I have a small oil leak I have to find, and I know that I should probably replace the PCV because there is no telling how old it is.
The rear heater only blows cold air, i checked the hoses with the engine running and warm and they are cold where the go into the cab. Not quite sure where they connect under the hood though, gotta do more digging.
Anyway, just wanted to say hi

edit: Just realized there was an introductions section, could the mods please move this post for me. Thanks!

 

The rear heat tubes connect near the firewall, at the back of the engine. Two small hoses connect into fittings that are "spliced" into the main heater hoses. Chances are someone previous to you disconnected them because something was leaking.

 

Your leak is probably the same one I have at the oil cooler, only leaks when engine is running, cost 11 bucks at toyota for the 2 orings to fix it. Search on here and you'll find some writeups, leaks pretty good though and will drip down everytime and whereever you go because it is leaking anytime the engine is on.

 

I'll check out the oil coil for sure.
As far as the rear heat goes is there a valve in those lines somewhere to control coolant flow or is it open and flowing all the time. I think I located them in the engine bay, about 90% sure, but there doesn't seam to be a valve. For some reason I'm expecting a valve there.

 

The valve for the rear heater is under the console. The lever you use to control hot or cold air IS the actual valve