reduced RPM

[habitat7@msn.com]

My DF115 (2005) looses rpm when above 2200 rpms. The rpms come right back if you pump the bulb.
I have changed both filters and drained and cleaned water separator with nothing to report. I have cleaned the screen and changed the high pressure pump but have not change the low pressure pump.
I see no leaks. What else might cause this? I am ordering the low pressure pump.

[redlowrey]

My DF115 (2005) looses rpm when above 2200 rpms. The rpms come right back if you pump the bulb.
I have changed both filters and drained and cleaned water separator with nothing to report. I have cleaned the screen and changed the high pressure pump but have not change the low pressure pump.
I see no leaks. What else might cause this? I am ordering the low pressure pump.

For the high pressure pump to work it needs supply from the low pressure pump to fill the vst. Start looking at the low pressure pump to the vst.

[artdf175]

have you checked the air vent to the fuel tank?
if that gets plugged up or not open, depending on tank configuration, can cause a vacuum which in turn reduces fuel flow to the engine