a)High draw rate from consumer can also result in low discharge pressure.
b)If the suction plate valves in the compression cylinder are leaking, then compression capacity will be reduced, leading to low discharge pressure. This will also lead to high discharge temp.
Larbi
Base on my experience in all kinds of reciprocating compressors the leakage in check valves is the most common issue. All of those check valves are flat with soft surfaces, so, the dirt oil or other debris in the oil causes a gap between the valve and their seats, then passing the high-speed air or other gases make the valve hot and deformation appear. For solving this problem you should change the valve or furbish it with a special paste.