Fuel Line Pressure Inspection (Protege & Protege5)
- Disconnect negative battery cable. Release fuel pressure. See FUEL PRESSURE RELEASE . Disconnect main fuel line quick release connector from fuel rail near pulsation damper. Refer to FUEL LINE CONNECTORS (MAZDA6, MIATA, MPV, PROTEGE & PROTEGE5
under FUEL SYSTEM in REMOVAL, OVERHAUL & INSTALLATION article. Install Fuel Pressure Gauge (49-N013-1A0C) between main fuel line and fuel rail. Turn lever on fuel pressure gauge as shown in Fig 1. Reconnect negative battery cable and go to next step.
Courtesy of MAZDA MOTORS CORP.
- Locate DLC-1 on left side of engine compartment. Connect a fused jumper wire between DLC-1 F/P terminal and body ground. See Fig 2. Turn ignition on and pressurize fuel system. Inspect fuel line pressure. For fuel pressure specifications, see FUEL SYSTEM
in SERVICE & ADJUSTMENT SPECIFICATIONS article. If fuel line pressure is high, go to next step. If fuel line pressure is low, go to step 4.
Courtesy of MAZDA MOTORS CORP.
- Check fuel pump maximum pressure. See FUEL PUMP PRESSURE INSPECTION (PROTEGE & PROTEGE5) . If fuel pump maximum pressure is as specified, check for plugged or restricted fuel return line or fuel pressure regulator. Repair as necessary. After repair, go to step 6.
- Check fuel line pressure for change while turning lever on fuel pressure gauge as shown in Fig 3. If fuel line pressure quickly increases, inspect fuel pressure regulator. If fuel line pressure gradually increases, inspect fuel pump maximum pressure. See FUEL PUMP PRESSURE INSPECTION (PROTEGE & PROTEGE5) . If fuel pump maximum pressure is normal, inspect for restriction between fuel pump and fuel pressure regulator. Repair as necessary. If no problem is found, go to next step.
Courtesy of MAZDA MOTORS CORP.
- Turn ignition on for 10 seconds to operate fuel pump. Turn ignition off and disconnect fused jumper wire. Wait 5 minutes and observe fuel pressure. See FUEL HOLD PRESSURE SPECIFICATIONS table. Check for changes in fuel pressure while turning fuel pressure gauge lever as shown in Fig 3. If fuel pressure holds, replace fuel pressure regulator. If fuel pressure does not hold as specified, inspect for fuel leaks from fuel line and fuel injectors. See FUEL CONTROL
under FUEL SYSTEM in SYSTEM & COMPONENT TESTING - MAZDA6, MIATA, MPV, PROTEGE & PROTEGE5 article. Repair as necessary. After repair, go to next step.
- Disconnect fuel pressure gauge and reconnect main fuel line to fuel rail. Pull on main fuel line to ensure quick release fitting is engaged to fuel rail. Attach lock clip to quick release connector in direction of fuel rail and lock it. See FUEL LINE CONNECTORS (MAZDA6, MIATA, MPV, PROTEGE & PROTEGE5
under FUEL SYSTEM in REMOVAL, OVERHAUL & INSTALLATION article. Complete AFTER REPAIR PROCEDURE .