Atlas copco xas 97, starts and runs well pressure builds when valves closed. I have adjusted the regulator, it appears to work but it still shuts down when valves fully closed. New unloader valve assembly has been installed already
In what way does it stop? Does the engine bog down, does it simply stop (like a normal stop).
If the engine bogs down, it’s probably that it can’t handle the load at higher pressure or the rpm drops too low.
Does is run well at full power? That is, with max air delivery (valves 3/4 open?), and at maximum pressure (so don’t open the valves completely, as the pressure will drop again).
Please check that and let me know what happens.
If this only happens with valves closed / engine running stationary – please check the idle RPM.