Hesitation and Random RPM drops

Heres the deal. I have been struggleing with this problem for some time and i'm getting pissed off so please only comment if you know what you are talking about. That said here is the problem. When i'm going 50 or faster and i stop accelerating my RPM's drop to about 2000 and stay there. If i want to accelerate from 50 i have to let up off of the gas and the car jerks a little then i can accelerate. It does this at all speeds over 50. Also when i accelerate at any speed when i get to around 3000 RPM she hesitates and it feels almost as if the engine is cutting in and out. i've replaced the fuel filter, TPS, and the computer keeps sending a misfire code. In responce i have replaced the #3 spark plug(which was cracked) several times now. Any ideas?

In responce i have replaced the #3 spark plug(which was cracked) several times now. Any ideas?

Bad plug wire can cause that problem,outside hairline crack in the porcelain.Sounds like it maybe time for new plug wire's.

~Larry~