My 93 Cherokee 2.5 L is backfiring and I can't find a solution
 

Any advice on a backfire problem? I've replaced the plugs, wires, cap and rotor, and fuel injectors with no luck. It backfires randomly (in all five forward gears, in all weather and and any RPM.) It's not a constant thing, but extremely frustrating and somewhat dangerous. I lose all engine power and have to either let off the gas, or floor it to avoid the bang. Any help would be appreciated! Could it be a timing issue, or oxygen sensor maybe?

My thoughts would be a fuel filter? Or timing, If it was timing tho it would be constant, Maybe water in the fuel, I would goto the auto parts place and get a bottle of HEET poor it in there and see if it helps, if not change the fuel filter.