Have an Volvo L120H, engine is stalling when hydraulics used at low Idle, mainly at end of lift stroke when more load is put on because of tilt cylinder being extended. Hydraulic pressures in spec, no active faults, idle currently set at 900rpm. Doesn’t seem to stall when driven. As soon as let go of hydraulic levers pumps return to standby.
Do you have break out Ts to monitor LS pressure against working pressure. If your pump is not destroking, the horsepower drain vs available @ idle will be upside down and cause a stall. I would test this, Pump 1 by itself, and then Pump 2 by itself. When you test Pump 2, also check steering , deadheaded against the frame lock. Steering runs at a reduced pressure of 3200 psi iirc. Pump 2 supports steering until demand is satisfied, then shifts remaining flow to work. . Pump 1 performs work alone. When isolating pumps, only plug the hoses, one at a time. DO NOT cap the fitting @ the compensator. Be mindful of oil coming from compensators. Any compensator flowing oil, should be considered defective. The leakage may cause the pump to stroke itself up if the volume exceeds the drain capability of the hose. Good luck
I should have been more clear, plug the LS hoses to check pumps. Check pump standby with LS disconnected. Make sure each pump is at spec..they're different. That's important or they won't sequence or stroke up properly. Then check max pump pressures individually by removing LS effectively taking that pump out if the equation.