Are you using a real R134 recover and recharge system or just the Wal-Mart special?<p>If its the AC in a can from Wally's you can't really go by that gauge. They aren't very accurate. I just put it enough to where my compressor is cycling properly and the AC is getting to the correct temp.
You're getting close to 100? That's with the compressor off, right? The compressor has to be running (A/C on) for you to get a correct reading....but like jrodT5 said, just recharge until it's not clicking on and off...a can of it opened up while sitting in a container of warm to hot water always helps the gas go into the system faster- that's what I do.
Actually, when it goes in real fast, there's a good chance the refrigerant is going in a liquid state. Depending where in the (low) line the charge port is, the liquid won't evaporate fast enough and enter the compressor, which isn't really good for it.<br>If not that, it'll raise the pressure in the system, causing the compressor to cycle off until it goes back down. So might as well not just dump it all in so fast.