Fuel Pressure Hold Inspection

Disconnect negative battery cable. Release fuel pressure. See FUEL PRESSURE RELEASE . 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 .
Locate DLC-1 under hood. Connect a fused jumper wire between DLC-1 terminals F/P and GND. See Fig 1 . 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 table. Go to step 4 .
Locate and remove fuel pump relay. See FUEL PUMP RELAY LOCATIONS table. Connect fused jumper wire between ground and fuel pump relay socket terminal No. 30. See Fig 2 . 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 table. Go to next step.
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 . Also check for injector fuel leakage. See INJECTOR FUEL LEAKAGE INSPECTION .

Fig 1: Identifying DLC-1 Terminals
Courtesy of MAZDA MOTORS CORP.

Fig 2: Identifying Fuel Pump Relay Socket Terminal No. 30
Courtesy of MAZDA MOTORS CORP.

FUEL PRESSURE HOLD