B2200 Stumbles under acceleration

[alexgohard]

My 93 mazda B2200 runs fine when idleing, and when you take it out of gear and hit the gas, but when it's in gear it accelerates till about 1400 rpm then falls flat on it's face. Any ideas?
P.S. I've changed spark plugs, wires, cap, rotor, fuel filter, air filter, and vacuum lines just to eliminate all the common problems. Thanks Alex

[Tyranitar]

If you have a MAF sensor, clean it with throttle body cleaner. Also you can get MAF sensor cleaner as well, have seen it at NAPA. Also, you should check your computer per the specs on AVPros website just in case your year is affected. Here is the link.
http://www.avproecm.com/mazda.htm