My case 90xt lifts great at an idle when cold, when it gets warm it doesn't want to raise unless ½ or ¾ throttle even then very slow where do I start?
An educated guess says that your pump is on the way out. However a flow test is in order, A tech that knows his flow meter and test specs and testing procedures would be worth the money spent. If I were the one doing the test I would do a test right off the pump outlet. If your tech does a tee test on the pump outlet after verifying the pumps condition, he can check every function in one hookup.
I was trying to figure out there are so many things that could cause it. My auxiliary pressure at idle is 1700 psi but if I hold it it will peak at 1700 then start to drop.