1993 crown victoria stumbles but never stalls

I have changed  wires plugs and ignitions coils and noticed a performance increase but
did not solve the problem. When i apply a heavy amount of gas  the car bogs down
and spews out some funky fumes ocassional backfire and eventually clears or forces
the stoppage out and away by appliing a smooth even gas flow via the pedal restoring
power until i settle back down to idle at a light or turn where it seems to bog down
again...... while its at a cold start the problem is sever but after i can rev the engine
and blow out and clear the line as it seems the problem is lessened after warmed or
cleared the first time.... but never completly .... no matter hot or cold it continues to
have a restriction in power during acceleration.... when its clear and gas is smoothly
applied it has tons of heavy raw power .... gas it the wrong way too hard  or
something... and engine cuts down to a putt.....a simple checklist of things i could
rundown could save me a ton of money on mechanics as i can install almost anything
but i dont know a ton about this issue please help...... things I am going to try
tomorrow.... MAF cleaning  and thorough check for vacume leaks between maf and
intake