I have a komatsu pc160-7 that pulses/jerks while tracking and using boom functions. Together or independently. It doesn’t matter. When I flip on the pump emergency override it runs smoothly but slow. Throws an e02 code. I can disconnect the pc epc solenoid at the pump and it runs fast and smooth but boggs the engine down. I have swapped pc-epc solenoids with no change. The pump was replaced with a rebuilt one a few months before. We thought the pump was bad. It had around 5500 hours on it. But no difference. Rotary manifold was rebuilt. The controller was also replaced. The voltage fluctuates anywhere from 9 volts down to 4 volts from the controller to the pc-epc. Is that normal? It has me puzzled. Any advice is appreciated.
What about bucket and arm functions under load, do they surge or pulse? Or are they smooth? Have you checked return filter for brass and iron in the well? Carefully cut apart the filter mesh to see what it reveals.
Arm and bucket functions do the same. Pulses under a load or not. The return filter was split and changed. No metal. Thanks for the reply.
Have you checked the monitor panel for fault codes? You can get into the diagnostics on the monitor by pressure the up triangle button and then 1, 2 and 3 in succession and the menu will change. You can move down the menu to mechanical and electrical faults and then enter either. It will show the active and logged fault codes.
When you're in the monitoring section as John C has advised you can see all your values from your EPC valves and pump pressures. Another thing to consider is, perhaps your control pressure accumulator is weak or flat. If it is, combined with age and hours, you may not be maintaining control pressure. We need to split this up, servo/control and pump/work. Maybe we can narrow the point of view.