AC only cools on decel

so, man, i've had an adventure with the ac on this thing

when i first got the car, i sucked down the freon, and measured it, it had a bit over a pound, which according to all info i found, was in line, so i knew it had no leak, just didn't work

after doing some searching, i came to the conclusion of buying a RCV for the compressor...i get under and look at it, order the one with the circlip...when i get around to actually installing it, turns out my damned car has the hex bolt one...so, i order it...then install...

i bought the car in october, i get around to finally installing the correct rcv in about january, maybe march...damned thing still didn't work

so i resign myself to the fact that it's either electrical, or a failure in the compressor

this past week, i was driving to school one morning, and i felt cold air out the vent...turned ac on, and by god, it worked, at speed, not at idle, which is fine, car has some crap looking aftermarket fans on it, anyway, all week, it was intermittently working, but over 50 percent of the time

get in it yesterday, and it doesn't work at all...except when not on the throttle

as in, i can be in 5th gear, let off the gas pedal, and let the engine coast down, and the air gets cold...but, if i set cruise, within seconds, it gets back warm

i'm gonna say this is prolly some type of weird mechanical failure inside the compressor, and i found a kit on the ebay that comes with the compressor, oil, a condensor, and a h valve for about 50 bucks cheaper than i can find a compressor only local

tl;dr

anyone ever have the ac on their jetta only work when not on the throttle? and if so, did a compressor fix it?

i'm assuming here that all the electrical side of things is fine...

AC only cools on decel