Help! 2.3L 85 ranger Backfires thru intake

I purchased this ford not too long ago for dirt cheap. the previous owner said he replaced the timing belt. When the engine runs at low RPM the backfiring from the throtal body is almost random. however at the backfiring is very steady. After smoking several cigars and going thru some beer. I went thru and disconected the sparkplug wires one by one and found that the #1 cylinder is causing the problems. I dont know if its a bad fuel injector or a bad valve. Can someone HELP PLEASE.

the backfiring is steady at high rpm

Sounds like you have to verify the valve timing, since it is a new timing belt and the truck was dirt cheap the previous owner probably installed the belt close enough to run, but not properly. hopefully your only looking at some new gaskets and your time fixing it right.