AC Takes forever to blow cold.

[FRod1981]

I can't find any actual help on this. So like the post says, when the car sits for a few hours, I start it and no cold air... for about 5-10 min. It seems like the car needs to be in the normal part of the temp gauge (not cold) and also I need to rev it above 3k or so just to get it to kick in. I had the R134 removed and replaced and was down .2 lbs but now its back to full, same problem.. When its cold it blows cold the entire time and even if I leave it for up to an hour it comes back on immediately. I can't figure out what I need to replace? the compressor? its compressing fine.. a switch? which one?.

Help.