Reocurring problem

I have a 96 honda accord lx nonvtec. Seems like the engine drops rpms then is stumbling trying to accelerate and then it will jump back up to the 3-4000 rpm were it should be. After testing and cleaning the fuel injectors the car seemed to run good for about 3 days then same prob again. But this doesnt happen all the time. It will do it out of a day about 1 or 2 times then runs fine. But the car just doesnt feel like it use to. So i got my emissions update from honda(new sparkplugs, wires, distributor cap and rotor and oilchange), Changed the fuel filter, put water remover in the gas, checked the fuel injectors, Also my throttle cable was loose but tightened now, and the trans fluid is good. NO engine light! Please tell me if im wrong but if the timing is off, my crankshaft position sensor should go off? Whats wrong?