Toyota Repair: Loss of power, fuel contamination, 22r engine

Question
I recently purchased a 86 pickup with a 22R engine, it was sitting in a garage
for quite a long time, If i lock the choke the truck fires right up at fast idle
about 3000 rpm but when i kick the choke off it coughs and stalls. if i drive
it, it chokes and backfires with no power. It had some old gas in it though i
replaced the fuel filter topped off the tank with premium gas and put about
half a litre of methal hydrate in the tank. I took it to a mechanic i know who
is good with carbs and he replaced plugs (said they were fowled) and cleaned
and adjusted the carb. I picked it up and it ran good for about 2 miles then
the problem resurfaced again. is there another fuel filter other than the one
in the passengers side back wheel well? Im at a loss for what to do next?

Answer
It sounds like there is some fuel contamination going on still, there is only the one fuel filter. Pump some fuel from the fuel line into a clean glass jar and take a look at the fuel, check it for any seperation in the glass. Other than that I would recommend having that mechanic that knows carbs overhaul this carburetor.