NEED HELP

ok heres the deal , when i start my jeep it stumbles and some times it dies and when i put it in gear. when i start driving it some times backfires in the intake and when i give it gas it slowly revs up and shifts suddenly and and throws me in the seat ? i have no clue what can do all this? need help?
it a 91 XJ with a 97 motor with a the 91 intake and wiring
its ran perfect since January?

Check your vac lines, fuel pump, fuel pressure regulator and your catalytic converter.

Do you know that the plugs, wires, cap and rotor are all good? Basics first.