I have some problem in my excavator, it's hitachi zx350-3 , when I'm increasing rpm all functions will be very slow , but if rpm at the low idle functions will be good so I can't understand this problem.
Do you have any service codes ? @John C. posted a good video on accessing the Hitachi ZX-3 diagnostic menu. .
Thanks for your reply, but I don't have any service code , because this option for troubleshooting not available in my machine, but I noted one thing there , when I removed electric socket for pump flow solenoid then excavator worked normally
Was the Alarm lamp on at anytime before you unplugged the solenoid ? See screenshot below.