I just bought a 93 Accord and it has a cruise control that is physco and I'm lost on how to fix it.

The master switch seems to work and when I press "set" the instrument cluster "cruise control" light sometimes (pressing the set button 15 times) comes on but even it does usually nothing happens. Once it actually did work, and twice the car started accelerating faster and faster but 99% of the time the car nothing happens.

I have the Honda service manual for the car and tested all the inputs (power, set, resume, speed etc) to the cruise control computer and they were OK so I replaced the cruise computer yet it hasn't made any difference at all. I've tested the vacuum solenoid/actuator and it worked (pulled in the actuator rod and held it), however, the vent and safety solenoids did not seem to function.

I am wondering if faulty vent/safety solenoids would cause the scenario as described above?