i have a 1987 325is bmw. lately the things lost like all its power. i have to flour the thing just to like get around bc it will stall out if i dont. i have changed the cap, rotor, spark plugs, fuel filter, mass air meter, main computer, coil and timeing belt. ive had the compresstion tested, the valves tested, the fuel injectors tested, and some sencers like cold start and another senser that counts the teeth on the flywheel and therers not air intake leaks. i have no clue what else there is to cheak. please someone help me.