It's under the intake manifold on the engine. You have to reach around and under the manifold to get it out, it's easier on trucks that don't have air condition installed. Use a 12 mm socket wrench for removal.
I have a 1985 celica GT and the fuel filter is located above the oil filter on the engine block. If the ST model has a 22re engine it should be the same.
engine bay
Right below the oil filter.
Five Quarts with filter change!
The fuel filter on a Toyota pickup having a 22re engine is located on the left side, directly under the intake manifold. It is held on by two 12mm bolts. If you look under the truck, you will see the filter to the left of the oil filter.
Passenger side of the block, around the oil filter. http://www.pirate4x4.com/forum/showthread.php?t=618845
1985 22RE Toyota 4x4 SR5 Xtra Cab
The 22RE powered the 1985 to 1995 Hilux, the 1985 to 1995 standard pickup, and the 1985 to 1995 4Runner.
The recommended spark plug gap for a 1986 Toyota 22RE is .032"
Go through the front passenger side wheel well and its right beside the oil filter
well if the 1985 did have a 22re ya it wold fit on a 1993 but since they didn't have the 22re in 1985 yet you probably have a 22r or a 20r in the 1985. i would recommend just buying a reconfigured head for the 1993 22re they are cheep like 2-400 bucks then you know its all new and will work
The recommended spark plug gap for a 1994 Toyota 22RE is .032"