The A/C in 2008 fit has been a little weak when I stop, but goes back to blowing cold when I start moving again. Last night, I added some 134 using an AC Pro kit. It seemed to bebworking ok when I went to bed. This morning, I get in, and notice the condenser cycles on for a second, then shuts off for about 8 to 10 seconds. The engine seems like it is really being affected when it cycles on, with a very noticeable drop in revs (never did this before). Is this from an overcharge, OR, could it be that after adding Freon, the little valve stuck a little bit and allowed a leak. Since the condenser only runs for a short time, the pressure gauge on the ac pro isn't really able to show me anything. When the condenser is off, the gauge shows overcharged (as it is supposed to), but then drops down once the condenser kicks on. About as soon as the needle starts to drop, the condenser turns off and the needle jumps back up.
Any thoughts?

 

Sounds like you overcharged the system.

 

ezone, you were correct;
DARN AC PRO guage!