How can I improve the response of this system with a hydraulic motor?

I am trying to get the response of a system that converts the motion of a cylinder into rotational energy in a hydraulic motor. I think the design is fine, but the parameters don’t quite fit. The hydraulic motor is 250 cc.

I have a problem with the accumulator as can be seen in the figure Mid_Scope. I have tried varying the parameters many times, but I cannot smooth the signal.

The hydraulic motor also gives a very poor response: e-6 (Fig. w_Scope).

I would be grateful if someone could give me some advice to improve the results. Thank you very much in advance.

[Pat Gipper]

I don't have Simscape Hydraulic, but there is nothing in your schematic that keeps the cylinder displacement flow from going right back into the the tank. Maybe you need to add two more check valves that direct the flow through the existing check valves and prevents the backflow.

[Pat Gipper]

The check valves would be placed in the lines just above the SCOPE 1 and SCOPE 2 measurement points, with the check valves A port pointing down towards the tank.