Airdog trouble shooting:
Loss of Fuel PSI/Running Out of Fuel
Initial question: Do you have flow from the PureFlow

product?
If the answer is yes, where is the location of the gauge port being used?
The gauge port in the filter housing will not work when the fuel is routed around the stock fuel filter housing.
The gauge port utilized may not be in the pressure stream of fuel.
The pressure gauge is not reading pressure.
The vehicle is receiving fuel; however, the pressure relief for the pump (ex.: VP-44 / CP-3) is open and allowing fuel to return to the tank through this pump.
Pinch the line going to the pressure pump to stop the flow of fuel after the pressure gauge. Remove the relay from the unit's wiring harness. Place a jump wire between the red and yellow wires in the relay socket. Read the pressure in the dead head mode.
If the pressure goes up to the desired pre-set pressure, the problem is indicated to be with the pressure pump relief mechanism.
If the pressure does not show on the gauge, the problem is indicated at the unit or gauge. Check to another gauge.
Check the line connections. Engine to engine. Tank to tank.
Remove the Return to "Tank" fitting. Spring and ball in the pocket? Properly seated?
Remove the gerotor cap. Is the gerotor turning?
If the electric motor is running and the gerotor is stationary, pull the center gear off the motor shaft. Is the flat inside the gerotor center gear rounded or missing?
If the electric motor is running and the gerotor is turning slowly, check the voltage to the motor. Low voltage will reduce the motor RPM's; hence, reduce or stop pressurized flow.
If low voltage check the wiring connections and voltage regulator.
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