RG987

Hi everyone, i have a 97 civic cx 1.6 non vtec, the car started jerking while driving and would not go past 40mph, while it idles its fine until you press the gas pedal the engine seems to loose power, i have replaced the map, tps, iacv, pcv, fuel pump, fuel filter, at a point i had a cel wich pointed to the map sensor which i have replaced with a new one twice and still shows up, i tested the connector for power, ground, and vacuum, passed, my car still jerks really bad and the same code shows up; map sensor, i am thinking about replacing the crankshaft position sensor, the car also has a new ignition coil, rotor, distributor cap, spark plugs and alternator and battery any suggestions as to what it could be? Any input will be highly appreciate it and thanks in advance.