Test 4: Fuel Delivery System

FUEL DELIVERY SYSTEM INSPECTION/ACTION CHART

BEST 4		FUEL DELIVERY SYSTEM
STEP	INSPECTION		ACTION
1	CHECK SYSTEM INTEGRITY Visually inspect the complete fuel delivery system, including fuel lines, connections, relays, damage to fuel tank, fuel pump, fuel pressure regulator, fuel pulse damper and fuel injector areas for leaks, looseness, cracks, kinks, pinching, or abrasion caused by a collision or mishandling. Visually inspect electrical harnesses and connectors for loose pins, corrosion, abrasion, or other damage from collision or mishandling. Verify vehicle has followed maintenance schedule. Verify fuel pump shutoff switch is set. See INERTIA FUEL SHUTOFF (IFS) SWITCH . Verify battery is fully charged (12.5 volts or greater). Verify electrical/fuse integrity. Verify fuel level is sufficient. Has any concern been found?	Yes	REPAIR as necessary. RERUN quick test. See PCM QUICK TEST .
1		No	Go to next step.
2	CHECK FOR VOLTAGE AT FUEL PUMP HARNESS CONNECTOR Verify fuel pump shutoff switch state. Follow the fuel pump shutoff switch reset procedure. See INERTIA FUEL SHUTOFF (IFS) SWITCH . Disconnect fuel pump harness connector at the fuel pump. Key ON, Engine OFF (KOEO). Connect WDS or equivalent tester. Select diagnositc data link. Select PCM. Select active command modes. Select output test mode. Select fuel pump pid. Press MODE to change to the ALL ON mode. Press start to turn on fuel pump circuit. Connect a multimeter between fuel pump power circuit (P/B) and fuel pump ground (B) circuit at the fuel pump harness connector. Was the voltage greater than 12.5 volts?	Yes	Exit Output Test Mode. RECONNECT fuel pump harness connector. RESTORE vehicle. Go to next step.
2		No	CHECK for opens and shorts in the fuel pump power and ground circuits. RESTORE vehicle.
3	CHECK FUEL FILTER FOR PROPER MAINTENANCE Locate and inspect the vehicle maintenance schedule and fuel filter. Was the fuel filter serviced according to schedule?	Yes	Go to next step.
3		No	REPLACE fuel filter. See FUEL FILTER . Go to next step.
4	CHECK FUEL PRESSURE WARNING: Before servicing or replacing any components in the fuel system, reduce the possibility of injury or fire by following directions in Section 01-14 (Fuel System) for cautions, handling and warnings. Install fuel pressure tester. Release fuel pressure. Key ON, Engine OFF (KOEO). Connect WDS or equivalent tester. Select diagnositc data link. Select PCM. Select active command modes. Select output test mode. Select fuel pump pid. Press MODE to change to the ALL ON mode. Press start to run the fuel pump. NOTE: The fuel pump will only operate for approximately 8 seconds when Output Test Mode is selected and activated. Is fuel pressure between 380-482 kPa (55-70 psi)?	Yes	Go to next step.
4		No	For fuel system with more than 482 kPa (70 psi): REPLACE fuel pump. See FUEL PUMP MODULE . RESTORE vehicle. RECHECK fuel pressure. For fuel system with less than 380 kPa (55 psi): Go to next step.
5	CHECK FUEL INJECTOR FLOW AND LEAKAGE Check injectors for leakage and flow rate using an injector tester Flow rate specification: 7.84 kg/hr (17 lb/hr) for 2.3L, 10.1 kg/hr (22 lb/hr) for 3.0L. Is the flow rate and leakage rate for the injectors tested within specification?	Yes	VERIFY no other leak exists. Replace fuel pump. See FUEL PUMP MODULE .
5		No	REPLACE failed fuel injector(s). See FUEL INJECTORS . RESTORE vehicle. RECHECK fuel pressure.
6	CHECK PULSE DAMPER DIAPHRAGM Start engine and run engine for 10 seconds. Key OFF. Wait 10 seconds and then start engine and run engine for 10 seconds. Key OFF. Remove vacuum hose from fuel pressure regulator or pulse damper port. Inspect for fuel in the vacuum hose regulator port or pulse damper. Is the vacuum hose and regulator or pulse damper port free of fuel?	Yes	REPLACE fuel pulse damper.
6		No	Go to next step.
7	CHECK FUEL SUPPLY LINE FOR RESTRICTION Observe Warning, Caution and Handling from section 01-14 (Fuel System). Disconnect fuel supply line at the fuel rail. Disconnect fuel supply line at the fuel pump. Check the fuel supply line for restrictions due to blockage, kinking, or pinching. Apply 21-34 kPa (3-5 psi) regulated shop air pressure to the supply line. Does air flow freely through the supply line?	Yes	Air flows freely. REPLACE fuel pump. See FUEL PUMP MODULE .
7		No	REPAIR cause of restriction. RESTORE vehicle. RECHECK fuel pressure.