So my AC cycles on and off a lot, and ive checked the usual stuff. Heres the history and what ive found out so far.

New compressor, refilled by mechanic. Low side reads about 35psi, low side pipe gets cool but not cold. Condensor fan works, relay checks out, AC is better in the morning when its cold out. AC cycles on and off when its really hot out.

Whats the problem??

 

The compressor cycles off for 3 reasons:

Evaporator has reached 40 F (clearly not the case here)
Engine rpm too low (it's about to stall)
Too much high side pressure (seems like that would be it)

You need to measure both pressures to diagnose. Or maybe the pressure is normal but the high pressure switch is triggerhappy.

 

i have the same problem, except my compressor's not new.
i tried doing the r134a conversion and it seemed to help a little but not enough.