Mazda MX-3 silhouetteMX-3

FUEL PUMP RELAY / PRESSURE REGULATOR

F2-113prose procedure

Replacement

  1. 1
    Remove the passenger side wall.
    Line drawing showing the fuel pump relay location behind the passenger side wall, with the relay connector and ECM bracket. An arrow points to a screw/fastener at the lower area.
  2. 2
    Disconnect the relay connector.
  3. 3
    Remove the relay from the ECM bracket.
  4. 4
    Install in the reverse order of removal.

Inspection

Operation check

Listen for operational sound of the fuel pump relay while the starter operating.

Continuity

  1. 1
    Check continuity between the terminals of the relay by using an ohmmeter.
    Left: drawing of the fuel pump relay with four terminals labeled (A), (B), C, D. Right: internal schematic of the relay showing the coil between terminals A and B and the switch contact between D and C.

Fuel pump relay continuity

Apply B+
Terminal C-DContinuity
Not apply B+
Terminal C-DNo continuity

PRESSURE REGULATOR

Inspection

Fuel line pressure

Fuel line pressure

  1. 1
    Disconnect the negative battery cable.
  2. 2
    Connect a fuel pressure gauge between the fuel filter and the fuel main hose. (Install clamps as shown.)
    Engine bay drawing showing a pressure gauge connected between the fuel filter and fuel main hose. Labels point to PRESSURE GAUGE and INSTALL CLAMPS.
  3. 3
    Connect the negative battery cable.
  4. 4
    Start the engine and run it at idle.
  5. 5
    Measure the fuel line pressure.
  6. 6
    Disconnect the vacuum hose from the pressure regulator and measure the fuel line pressure.
    Engine bay drawing showing the pressure regulator with its vacuum hose. A label points to PRESSURE REGULATOR; an arrow points to the vacuum hose connection.
Fuel line pressure (step 5)vacuum hose connected
210-260 kPa {2.1-2.7 kgf/cm2, 30-38 psi}
Fuel line pressure (step 6)vacuum hose disconnected
260-310 kPa {2.6-3.2 kgf/cm2, 37-45 psi}

See also

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