I think what I would do next is connect a set of hoses with the manifold gauges to the high and low pressure service ports and get some readings. When you take the readings see if you can have the engine rpm between 1500 and 2000 rpms. If the ambient temperature (temperature as measured about 2 inches in front of the condensor), with both fans running is
between 90 F and 100 F see if the low pressure is 30 psi and if the high pressure is between 165-270 psi.

Maybe you are just low on R 134a.