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Pump Sounds Intermittent or Noisy

With your engine off and your PureFlow® product in running form. The PureFlow® product will begin loud and get quiet very soon after purging the air out of the system.

It is normal for your PureFlow® product to repeat these noises. This is due to an uncontrolled amount of air coming from the tank. As fuel gets warmer, the foaming effect of diesel fuel worsens. This will cause an increase in noise as well. A good test to perform that will help determine how much air you are getting from the tank is the "Bucket Test."

If the noise has gone away or lessened. It will indicate the problem or restriction is in the connection at the tank or inside the tank. Inspecting your connection and tank module is necessary. This could range from a loose connection, crack in a suction tube or even a tank vent clogged.

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Pump Has Quit Working

  • Verify the power and ground leads are properly connected and connected well.

  • Verify the trigger wire(s) to the control relay are properly connected.

  • Verify the fuse is good in the wiring harness.

  • Verify the appropriate fuse is good in the vehicle fuse panel.

  • If all connections and fuses are good. Verify that you have power going into the lead to the PureFlow® product. (Test light suggested).

  • If all connections and fuse are good and a test light is not available, remove the relay from the wiring harness socket. Using an insulated jumper wire, jump the red and yellow wires in the relay base, female spade side. Do not start the engine.

  • If the unit starts running, the relay trigger connection is in question. Verify the relay trigger wire(s) are properly connected.

  • If the unit does not run with direct power, verify that there is nothing lodged in the Gerotor Assembly (Refer to the section in the manual regarding cleaning debris from Gerotor Assembly)

  • If the relay trigger wire(s) are properly connected, the relay is in question. For testing a standard 5 blade relay from under the hood can be used. Plug in the relay and turn on key to activate the relay and unit.

  • If you unit runs, replace the relay.

  • If the unit does not run, the trigger wire(s) / connection are in question. Verify the relay trigger wire connection again.

  • If the relay trigger wire connection is good, remove the relay from the wiring harness and check the continuity of the trigger wire(s) in the wiring harness.

  • No continuity: Replace wiring harness.

  • Continuity found: Verify power is available at the power source being utilized with a test light. Fuse and / or connection are suspected.

  • If the unit does not start with the jump wire in the relay socket, using a test light verify the power is to the yellow wire in the relay socket.

  • If the yellow wire in the relay socket shows power, go back to the fuse (between the relay socket and power connection), remove the fuse, and test for power to the red wire into to the fuse holder.

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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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Priming Issues

  • Pump Won't Prime: Loosen the fuel filter (not water separator) while the PureFlow® product only is running. This will allow the air to be released. The tone of the motor will change as fuel enters the gerotor.

  • Immediately after hearing the tone change. Tighten the filter back up.

  • Still Not Priming: Remove water separator. Turn the PureFlow® product on. Place your thumb under the water separator nipple. Ensure there is suction at the water separator nipple.

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Hard Starts with Dodge 1998.5-2002 w/VP44 Injection Pump

  • Did the truck start good before the PureFlow® product was installed?

  • Has your injection pump seen more than 100,000 miles? Have you injection pump tested at your Dodge dealership or authorized shop.

  • Before the PureFlow® product was installed, were you seeing symptoms of a dying lift pump? What were the pressures you were seeing? Below 10 psi will damage a VP44.

  • Do the hard starts occur more often when warm conditions are present? If you experienced any of the above problems. Start the vehicle immediately after entering the key into the ignition. Do not wait for the wait to start light to go out.

It is important that your ECM re-flashings are up to date. Contact your local dealer for the most recent re-flash.

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Bucket Testing - Isolating the Pump From the Tank

  • Add 3-4 gallons of diesel fuel to the bucket.

  • Remove the suction line from the top of the tank and drop into the bucket of fuel.

  • Place the return line from the PureFlow® product in to the bucket.

  • Ensure correct voltage is at the PureFlow® Product.

  • Turn the PureFlow® product on and view the output to engines fuel pressure and/or volume.

Only an obstruction in the suction line or a clogged water separator can affect the performance of this test.

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