Cruise control


I have a 1984 Camaro Z28. The problem is the cruise control.

I set the speed and the control engages but the speed continues to increase.

If I set it at 60 mph, in less that 5 seconds the speed may be at 65 mph.

It does not stop, I have set it at 60 and moments later it is at 85 mph.

I do not see a vacuum leak and the unit seems to be intact.

Any thoughts?