General Pinpoint Test 5: Fuel Delivery System

PINPOINT TEST 5 - FUEL DELIVERY SYSTEM

PINPOINT TEST 5		INTERMITTENT
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 SWITCH REMOVAL/INSTALLATION . 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 ON - BOARD DIAGNOSTIC TESTS .
1		No	Go to next step.
2	CHECK FOR VOLTAGE AT FUEL PUMP HARNESS CONNECTOR WDS or equivalent tester connected. Verify fuel pump shutoff switch state. Follow the fuel pump shutoff switch reset procedure. See INERTIA FUEL SHUTOFF SWITCH REMOVAL/INSTALLATION . Disconnect fuel pump harness connector 0114-02 at the fuel pump. Key ON, Engine OFF (KOEO). Connect a multimeter between fuel pump power circuit P/B and fuel pump ground B/Y circuit at the fuel pump harness connector 0114-02. Enter Output Test Mode and turn on fuel pump circuit and monitor the voltage reading. Was the voltage greater than 12.5 volts?	Yes	Exit Output Test Mode. Connect 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. Check for last service date. Was the fuel filter serviced in the last 1609 Km (1000 miles)?	Yes	Go to next step.
3		No	Replace fuel filter. See FUEL FILTER REMOVAL/INSTALLATION . 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 direction in fuel system caution, handling and warning at the beginning of this test. Install fuel pressure tester. Release fuel pressure. WDS or equivalent tester connected. Key ON, Engine OFF (KOEO). Access Output Test Mode and run the fuel pump to obtain maximum fuel pressure. NOTE: The fuel pump will only operate for approximately 8 seconds when Output Test Mode is selected and activated. Is fuel pressure between 207-448 kPa (30-65 psi)?	Yes	Go to next step.
4		No	For fuel system with more than 448 kPa (65 psi): Replace fuel pump. See FUEL PUMP REMOVAL/INSTALLATION . Restore vehicle. Check fuel pressure. For fuel system with less than 207 kPa (30 psi): Go to step 7.
5	CHECK PULSE DAMPER DIAPHRAGM Install fuel pressure tester. Start engine and run engine for 10 seconds. Key OFF, wait 10 seconds. Start engine and run engine for 10 seconds. Key OFF, remove vacuum hose from pulse damper port. Inspect for fuel in the vacuum hose pulse damper. Is the vacuum hose and pulse damper port free of fuel?	Yes	Go to next step.
5		No	Replace fuel pulse damper.
6	CHECK FUEL INJECTOR FLOW AND LEAKAGE Check injectors for leakage and flow rate using an injector tester Flow rate specification: 9.5 kg/hr (21 lb/hr) for 2.3L engine/5.5 kg/hr (12 lb/hr) for 3.0L engine/8.7 kg/hr (19 lb/hr) for 4.0L engine. 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 REMOVAL/INSTALLATION .
6		No	Replace failed fuel injector(s). See FUEL INJECTION SUPPLY MANIFOLD AND FUEL INJECTOR - 2.3L REMOVAL/INSTALLATION , FUEL INJECTION SUPPLY MANIFOLD AND FUEL INJECTOR - 3.0L REMOVAL/INSTALLATION or FUEL INJECTION SUPPLY MANIFOLD AND FUEL INJECTOR - 4.0L REMOVAL/INSTALLATION . Restore vehicle. Check fuel pressure.
7	CHECK FUEL SUPPLY LINE FOR RESTRICTION Observe Warning, Caution and Handling at the beginning of this test. 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 REMOVAL/INSTALLATION .
7		No	Repair cause of restriction. Restore vehicle. Check fuel pressure.
Courtesy of MAZDA MOTORS CORP.