B2300, B3000, B4000 & Tribute 3.0L Mazda Tribute I

Install Fuel Pressure Gauge (49-UN01-010) to fuel pressure relief valve (Schrader valve) located on fuel rail. (Scheme 28) Place fuel pressure gauge drain hose in suitable container and release fuel pressure slowly.

Scheme 28

Scheme 29

Scheme 30

1. Disconnect negative battery cable. Release fuel pressure. See «FUEL PRESSURE RELEASE»(ref-134958-S02405930982002022100000). Install fuel pressure gauge in fuel supply line. Reconnect negative battery cable. On all models except 626, Reconnect negative battery cable and go to next step. On 626, go to step 3.
2. Locate DLC-1 under hood. Connect a fused jumper wire between DLC-1 terminals F/P and GND. (Scheme 29) Turn ignition switch on for 10 seconds to operate fuel pump. Turn ignition switch off and disconnect fused jumper wire. Wait 5 minutes and observe fuel pressure. See «FUEL PRESSURE HOLD»(ref-134958-S27619952382002022100000) table. Go to step 4.
3. Locate and remove fuel pump relay. See «FUEL PUMP RELAY LOCATIONS»(ref-134958-S24753694332002022100000) table. Connect fused jumper wire between ground and fuel pump relay socket terminal No. 30. (Scheme 30) Reconnect negative battery cable for 10 seconds, to operate fuel pump. Disconnect negative battery cable and fused jumper wire. Wait 5 minutes and observe fuel pressure. See «FUEL PRESSURE HOLD»(ref-134958-S27619952382002022100000) table. Go to next step.
4. On MPV, if fuel pressure is not as specified, check for leaks and fuel pressure regulator. On all other models, if fuel pressure is not as specified, check fuel pump hold pressure. See «FUEL PUMP HOLD PRESSURE INSPECTION»(ref-134958-S35784222572002022100000). Also check for injector fuel leakage. See «INJECTOR FUEL LEAKAGE INSPECTION»(ref-134958-S27178037762002022100000).

FUEL PRESSURE HOLD