What have you done so far?

Compression test or leakdown test? Valves - Rings ?

Vacuum problems? Leaking intake gasket or broken hose somewhere?

Ignition tuneup? What do the plugs look like? How is the timing?

Has it had ignition wires in the past 10 years or 100K miles etc?

Has it had a fuel filter in the past x # of miles or years?

Sort of go back to the basics to start with. If the engine internals are reasonably sound, then is it a problem with fuel or with spark? If you can narrow it down it should be easier to diagnose, and fix.

1995 V6 SR5 5 speed 4X4 - 4Runner - dark blue