Rep Power: 0

Well, all is not as well as I thought with my A/C. I recently repaired some wiring on my compressor and checked the field coil resistance and power continuity... everything checked out to spec, so I installed a new drier, installed the newly fixed compressor, put 4.2 oz. of oil into the system (4 oz in the compressor and .2 oz in the drier), bolted everything down, had a shop pull a vacuum on the system and recharged it with 21 oz. of R134a.

When idling, the A/C *will* blow somewhat cold and generally delivers a temperature of around 55F/13C when the ambient temperature outside is 90F/32C. However, if I open the throttle a little bit and rev it, then let off the throttle, the compressor will do something odd... it will cycle off/on VERY rapidly anywhere from 1-4 times within about 2 seconds, then resume spinning like nothing happened. While it does this, the delivery temperature shoots way up. The end result is that the A/C blows relatively cold when idling or during highway driving, but is almost non-existant in stop-and-go city traffic.

What is this super rapid cycling after throttling indicative of? I haven't gotten a set of manifold gauges to measure the high/low side pressure yet. I'm just looking for possible causes at this point.