Welcome to the board <img src="/forums/images/graemlins/kewl.gif" alt="" />

Sounds like you've got alot of troubleshooting done already.
When was the last time you did a tune-up?
Cap/Rotor/Plugs (and wires?)
I don't know if you have fuel starvation issue (filter), or a lack of spark. Also just for kicks, look over the tube from the AFM to the throttle body for hairline cracks in the rubber boot areas.
Hope this norrows it down for you.

Also, on a side note, you'll want Nippendenso or NGK plugs.

85 4Runner - With NEW Marlin 4.7 Gears!! It's a whole new beast!