Fuel Delivery Check

*CHECKING FUEL DELIVERY











Diagnostic Test

1. FUEL PUMP OPERATION





WARNING: THE FUEL SYSTEM IS UNDER A CONSTANT PRESSURE EVEN WITH THE ENGINE OFF. BEFORE TESTING OR SERVICING ANY FUEL SYSTEM HOSE, FITTING OR LINE, THE FUEL SYSTEM PRESSURE MUST BE RELEASED.

Verify that the fuel tank is not empty before continuing.

Turn the ignition on.

With the DRB III(R), actuate the Fuel Pump.

Listen for fuel pump operation.

Stop All Actuations.

Did the Fuel Pump operate?

Yes

- Go To 2

No

- Go To 4

2. FUEL PRESSURE





WARNING: THE FUEL SYSTEM IS UNDER A CONSTANT PRESSURE EVEN WITH THE ENGINE OFF. BEFORE TESTING OR SERVICING ANY FUEL SYSTEM HOSE, FITTING OR LINE, THE FUEL SYSTEM PRESSURE MUST BE RELEASED.

Turn the ignition off.

Install a fuel pressure gauge at the engine.

Turn the ignition on.

With the DRB III(R), actuate the Fuel Pump and observe the fuel pressure gauge.

NOTE: Fuel pressure specification is 3.7 to 4.2 bar (54 to 61 psi).

Stop All Actuations.

Choose a conclusion that best matches your fuel pressure reading.

Below Specification

- Go To 3

Within Specification

- Test Complete.

Above Specification

- Replace the Fuel Filter/Fuel Pressure Regulator.
- Perform POWERTRAIN VERIFICATION TEST - VER 3. Powertrain Verification Test - Ver 3

3. CHECKING FUEL PUMP INLET STRAINER

WARNING: THE FUEL SYSTEM IS UNDER A CONSTANT PRESSURE EVEN WITH THE ENGINE OFF. BEFORE TESTING OR SERVICING ANY FUEL SYSTEM HOSE, FITTING OR LINE, THE FUEL SYSTEM PRESSURE MUST BE RELEASED.

Turn the ignition off.

Remove and inspect the Fuel Pump Inlet Strainer.

Is the Fuel Strainer plugged?

Yes

- Replace the Fuel Pump Inlet Strainer.
- Perform POWERTRAIN VERIFICATION TEST - VER 3. Powertrain Verification Test - Ver 3

No

- Check the fuel supply line for a restriction. Repair as necessary. If OK, replace the Fuel Pump.
- Perform POWERTRAIN VERIFICATION TEST - VER 3. Powertrain Verification Test - Ver 3

4. FUEL PUMP RELAY OUTPUT CIRCUIT OPEN





Turn the ignition off.

Disconnect the Fuel Pump harness connector.

NOTE: Check connectors - Clean/repair as necessary.

Turn the ignition on.

With the DRB III(R), actuate the Fuel Pump.

Using a 12-volt test light connected to ground, probe the Fuel Pump Relay Output circuit at the Fuel Pump harness connector.

Does the test light illuminate brightly?

Yes

- Go To 8

No

- Go To 5

5. CHECK FOR AN OPEN FUEL PUMP FUSE 5

Turn the ignition off.

Remove and inspect the Fuel Pump Fuse 5 from the Relay Control Module.

Is the Fuel Pump Fuse 5 good?

Yes

- Go To 6

No

- Go To 7

6. FUEL PUMP RELAY OUTPUT CIRCUIT OPEN





With the ignition off.

Disconnect the Relay Control Module B harness connector.

NOTE: Check connectors - Clean/repair as necessary.

Measure the resistance of the Fuel Pump Relay Output circuit from the Fuel Pump harness connector to the Relay Control Module B harness connector.

Is the resistance below 5.0 ohms?

Yes

- Check the Fuel Pump Fuse 5 input circuit for voltage. Repair as necessary. If OK, replace the Relay Control Module.
- Perform POWERTRAIN VERIFICATION TEST - VER 3. Powertrain Verification Test - Ver 3

No

- Repair the Fuel Pump Relay Output circuit for an open.
- Perform POWERTRAIN VERIFICATION TEST - VER 3. Powertrain Verification Test - Ver 3

7. FUEL PUMP RELAY OUTPUT CIRCUIT SHORT TO GROUND





With the ignition off.

Disconnect the Relay Control Module B harness connector.

NOTE: Check connectors - Clean/repair as necessary.

Measure the resistance between ground and the Fuel Pump Relay Output circuit.

Is the resistance above 100 kohms?

Yes

- Replace the Fuel Pump and the Fuel Pump fuse.
- Perform POWERTRAIN VERIFICATION TEST - VER 3. Powertrain Verification Test - Ver 3

No

- Repair the Fuel Pump Relay Output circuit for a short to ground and replace the Fuel Pump fuse.
- Perform POWERTRAIN VERIFICATION TEST - VER 3. Powertrain Verification Test - Ver 3

8. FUEL PUMP





NOTE: Check connectors - It is critical that the connector is free from any signs of corrosion or deformities. Clean/repair as necessary.

With the ignition on.

Using a 12-volt test light connected across the Fuel Pump harness connector.

With the DRB III(R), actuate the Fuel Pump.

Does the test light illuminate brightly?

Yes

- Replace the Fuel Pump.
- Perform POWERTRAIN VERIFICATION TEST - VER 3. Powertrain Verification Test - Ver 3

No

- Repair the Fuel Pump Ground circuit for an open.
- Perform POWERTRAIN VERIFICATION TEST - VER 3. Powertrain Verification Test - Ver 3