I was recently given a 1986 Toyota pickup (22r) with a rebuild (75000 miles) by my mother.
This is the truck I learned to drive in and really want to fix it up for nostalgia and a first yota of my very own. I am deffinatly a newbie.
About six months ago It started losing power and has a sort of misfire sound that progressively turned into a loss of almost all power and the motor shaking violently when idling.
I checked the distributor and the plugs (slight black buildup on 3 and 4) and made sure the timing on the distributor was on the correct tooth and lined up at TDC #1.
The weridest part is it smoother without the #3 plug hooked up. Please help me as I love this truck and hate to see it hurting haha

 

It sounds like your plug wires aren't reversed or anything since it was running fine. I'm going to suggest a compression test first off.

 

I ran compression tests and found I had good compression on 1,3,4 but 2 had 0 psi. Maybe a blown piston ring or a bad valve? I also regapped the plugs and played with the distribution again to no avail

 

A stuck valve should be easy to see with the valve cover off, otherwise do a leakdown test and check your coolant/oil for contamination.

 

You could have a blown head gasket between the #2 cylinder and a water or oil port!