1998 Zx2 Cruise Control Problems

I have a standard 1998 ZX2. When traveling on the highway at about 60mph...... after turning on the cruise control then pushing the set button to a certain speed (say 60 mph) my vehicle will go up to about 70 without me pushing on the accelerator. I try to turn off the cruise control but will not turn off. If you put the car in neutral it just rev's up high. Turning the engine off quickly and back on while driving didnt do anything. After stopping, turning the engine off moving the control cable to the engine back and forth (which seemed to be in proper locations). I start the vehicle back up and then the cruise is off. Does anyone know what this sounds like? This has happened the last 3 times I tryed to use the cruise.

Thanks,
ddppci

Welcome to AF! Do you have an automatic or manual? Does the cruise go off if you hit the brakes? If a manual does the cruise go off if you depress the clutch?
The deactivator switch could be bad about shutting the system down. A loose or binding speed control actuator cable between speed control actuator and throttle body could cause the symptoms you are talking about. A binding cable will cause all the problems you have. It is easy enough to replace or lubricate with WD 40. A new cable would be the right way to go.