General
The fuel pump is located in the fuel tank. It delivers fuel to the fuel metering assembly. The fuel metering assembly contains the fuel injectors and the pressure regulator, where the system pressure is controlled. Excess fuel pressure is returned to the fuel tank by a return line. The ECM controls the system relay that supplies 12 vdc to the fuel pump.
When the engine is stopped, the pump can be turned on by applying battery voltage to pin 1 and ground to pin 3 of the fuel pump connector [86A] or by using the Scanalyzer.
Improper fuel system pressure may contribute to one of the following conditions:
- Cranks, but won’t run.
- Cuts out (may feel like ignition problem).
- Hesitation, loss of power or poor fuel economy.
Note. Refer to the VRSCA Electrical Diagnostic Manual for further information on the function and testing of the fuel system.
Testing
The fuel pressure gauge (0-100 PSI) allows for fuel injector and fuel system pressure diagnosis.
PART NO. | SPECIALTY TOOL |
HD-41182 | Fuel pressure gauge |
26338-68 | 1/8 in. pipe thread 90° (right angle) elbow |
1. See Figure 9-18. Disconnect fuel pump connector [141] from top of fuel tank.
![](https://motoinstruction.ru/img/harley/2/111277.jpg)
Figure 9-18. Fuel pump connector [141]
2. Start the engine and allow the vehicle to run.
3. When engine stalls, operate the starter for 3 seconds to remove any remaining fuel from the fuel lines. Turn ignition key off.
4. See Figure 9-19. Insert a 1/8 in. pipe thread 90° degree (right angle) elbow (1) between the fuel valve (2) and the Schrader valve adapter (3).
![](https://motoinstruction.ru/img/harley/2/111278.jpg)
Figure 9-19. Fuel pressure gauge valves: 1. 1/8 in. pipe thread 90° elbow; 2. Fuel valve; 3. Schrader valve adapter
5. See Figure 9-20. Remove protective cap from Schrader valve in fuel metering assembly.
![](https://motoinstruction.ru/img/harley/2/111279.jpg)
Figure 9-20. Schrader valve location
6. Verify that the fuel valve and air bleed petcock on the FUEL PRESSURE GAUGE (Part No. HD-41182) are closed.
![](https://motoinstruction.ru/img/harley/2/111280.jpg)
Figure 9-21. Fuel pressure gauge installed
7. Connect fuel pressure gauge to Schrader valve. Reconnect connector [141].
8. Start and idle engine to pressurize the fuel system. Open the fuel valve to allow the flow of fuel down the hose of the pressure gauge.
9. Position the clear air bleed tube in a suitable container and open and close the air bleed petcock to purge the gauge and hose of air. Repeat this step several times until only solid fuel (without bubbles) flows from the air bleed tube. Close the petcock.
10. Open and close throttle to change engine speed. Note the reading of the pressure gauge. Fuel pressure should remain steady at 380-425 kPa (55-62 psi).
11. Turn the engine off. Open the air bleed petcock to relieve the fuel system pressure and purge the pressure gauge of gasoline.
Warning! A small amount of gasoline may drain from the quickconnect fitting when the fuel supply line is removed. Thoroughly wipe up any spilt fuel immediately. Dispose of rags in a suitable manner. Gasoline is extremely flammable and highly explosive. Inadequate safety precautions could result in death or serious injury.
12. Remove fuel pressure gauge from the Schrader valve in fuel metering assembly. Install protective cap over Schrader valve.