ac compressor

hello, on my 89', the ac compressor clicks on and off approx every 8 seconds for the first 2-3 minutes i turn it on. this causes the car engine to rev up(increased load) everytime it clicks on. i have never heard a car rev up and down every 8 seconds like this, it sounds like the car is having problems, but it really isnt it just the compressor causing the rpms to increase a little, not to much. the engine is taking the load correctly, but why is my compressor constantly clicking on and off like that for only about 3 minutes?

The comp coming on will increase your RPM's to compensate for the increased engine load. Every 8 seconds sounds like it is low on freon. Is your AC blowing cold or just cool? Normal cycle time is in the 1 minute neighborhood.