350 is extremely high. indicative of a plugged or dirty condenser, or a fan problem on the condenser, or a heat source feeding the evaporator.
150 is quite low unless it's very cold in the car and outside.
you've got problems, and they are all over the map. start with tracing the leak, get it FIXED then evacuate the system and totally verify that there is no leak with pressure. put in 134 as a gas only up to approx 90 psi with the system not running, and let it sit overnight. recheck with the temps the same as they were when you put in the 90 psi, and see what your pressures are. anything less than 90, and you still have a leak. find it before you vacuum the system.

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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 560SL convertible
1987 190D 2.5-5SPEED!!!

1987 300TD
2005 Dodge Sprinter 2500 158"WB
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!