12oz cans through manifold like i said it's really weird compressor kicked on almost instantly when i started adding liquid charge
This statement really bother me!
Does this mean you were charging an empty system with LIQUID with the A/C On and the engine running?
Good way to ruin a compressor and put metal shavings throughout the system.
No oil circulation to lube the compressor when the system has no refrigerant charge.
Also You slug the compressor inlet with liquid and freeze damage the port valves. NEVER charge liquid into any running system.
DO you have the HIGHSIDE MANIFOLD VALVE open with the A/C unit running. If you port that much pressure back into the 12 oz can you'll find out the can can't hold that much pressure!
Make sure you are wearing eye protection when charging the A/C. It's hard to get your eyes replaced after a relief valve or hose fitting sprays refrigerant in your face!!!
Could be your condenser inlet (or some spot further down the high side line) is completely plugged and going nowhere. But the really high side pressure is bleeding back through the compressor high side to the low side.
P.S. Its NOT your gauges.