why does my 89 jeep Cherokee start and stall and shakes bad then dies? ?

i just bought this jeep not running put good gas in it and got it running. it starts idles up to 1500 then drops to about 200 and shakes like its gonna die (it will die) if i pump the gas i can get it rev up and steady out at like 3000 rpms with it sputtering and a back fire once in a while. When it does die it will start right back up and do the same thing. I am stumped thinking fuel pump? cap, rotor, and plugs are all new including fuel filter. any ideas would be great. Thanks
Cap, rotor,plugs, wires and fuel filter are all new.

make sure that all of your vacuum lines are connected and in good shape. You might want to adjust the throttle cable also.
Could be fuel pump, as you suggested.
good luck