Your RPM jumping is your computer reacting to an inaccurate reading from one of your sensors. mostlikely your loosing air pressure on the back side of your MAF sensor. Each time your RPM's comes up the engine flexes backwards and exposes a loose connection on the air intake or crack in the intake and you loose vaccume pressure. then the computer cuts back on the injecters and your RPM's go down allowing the engine to flex forward again and it starts over. There is your RPM jumping.
I agree with SGT_CRUMP, I had the same problem, replaced the sensor and RPM prob was fixed completely. Injector cleaner fixed it temporarily then a few months later started acting up again so I replaced the sensor..
I NEED HELP BAD MY CAR HAS BEEN SITTIN UP FOR ABOUT 4OR 5 YEARS JUST GOT IT AND PUT PLUGS AND PLUG WIRES AND NEW DIS. CAP AND ROTOR BUTTON AND WHEN I I PUT IT TO THE FLOOR IT CUTS OUT I DONE CHECKED THE FUEL FILTER IT AINT THAT SO ANY SUGG. LET ME KNOW