Deere 690C excavator It will run fine wide open for about an hour and then will start starving for fuel. I can see air in the glass fuel filters. It will idle rough and then finally catch up with itself and then idle fine but will not stay running at higher rpm’s. If I let it sit for a day it will run fine for an hour again and then start acting up. Backstory: I had to replace fuel tank and lines shortly after buying it as the tank was rotted out. I replaced the fuel supply line with 3/8 hydraulic hose. Also replaced all the filters twice now and replaced the lift pump. Right before it begins to die out, when I operate the stick it really loads the engine hard. Do I have a fuel issue or a hydraulic issue?
Sounds like a fuel issue. Check the inlet / check valve fitting at the fuel filter housing for any debris partially blocking fuel flow.
Type one
type 2
Also check the fuel tank vent.