I am new to the site and need some help. I have a bobcat S175 skid steer. The unit has 450 hours. After using it for a few hours, it started developing a problem where it would die under load. It would not matter if the load was from operating it across terrain, or load from the bucket or other accessories. I changed the fuel filter and all hydraulic filters. I checked all the fuel lines to make sure they were clear and fuel would run through them without a problem. Also made sure the pick up tube was not clogged. My dealer advised aftermarket fuel caps sometimes cause a problem if they’re not vented however, I checked mine and I do not have a fuel ventilation problem. I disconnected the primer bulb and manually pump fuel through it and it ran freely when it loses power. It is not always immediately after starting. Sometimes it would take 10 minutes for it to develop the problem. Once the problem starts, the engine seems to run rough. While having the problem, I checked the primer bulb and it was not collapsed. However, when I pumped the primer bulb, the rough running engine cleared up. I’m thinking it may be a fuel pump issue. Any help would be an appreciated.
Fuel lift pump. Best way to check is test fuel pressure after lift pump. Oh, and a 450 hour S175 is a rare find. Nice machine!
What is the best way to check the fuel pressure after the lift pump? What type of readings should I look for?
The fact that the rough running engine cleared up a bit when you pumped the primer bulb is an indicator the lift pump isn't working properly. I'd replace the lift pump and see if the problem goes away, they're not that expensive.
those lift pumps dont put out much pressure at all, maybe 2-3 PSI