my ka24se

i was wondering if anybody knew what was wrong with my engine. see when i first crank it sometimes it just sits there and stmbles under 1000 rpms and when i hit the gas it does nothing but after about 2 minutes of cutting it on and off it finally cranks but runs real rough any help would be greatly appreciated

try tuning it up. spark plugs, plug wires, distributor rotor and cap, fuel filter, change oil