Genuine Mitsubishi Montero Fuel Pump

Mitsubishi Montero Fuel Pump Parts Questions & Experts Answers

• Fuel Pump
  MB831691
  Q: How should the fuel pump be tested for correct pressure on Mitsubishi Montero?

  A:

  In models which use the carbureted type, the fuel pump must be tested to ensure that it is in proper pressure even when still in the car. Check the fuel pump pressure, assemble a T fitting, a hose length the same length as the inside of the fuel hoses, a fuel pressure gauge and a tachometer. Unscrew the hose clamp, and disconnect the hose on the fuel pump outlet fitting, and then insert one end of the T fitting into the hose that was removed and screw the clamp. Take a short piece of hose and one end and hook it on the T fitting and the other end on the fuel pump outlet fitting. Attach another piece of hose (approximately six inches) between the fuel pressure gauge and the remaining portion of the hose on the other end of the T fitting making sure that all connections are fastened with the hose clamps. Unscrew the fuel return hose of the carburetor and put a plugged short piece of hose in the hose. Install tachometer according to the instructions of the manufacturer. Turn the engine on and run it a little to get the air out of the pump to obtain an accurate pressure reading. Adjust the engine idle speed to the proper level then make a note of the pressure reading on the gauge. When switching off the engine watch the gauge; the pressure must not decrease, it should go back to normal gradually. In case the pressure goes beyond stipulated limits or decreases to zero immediately the engine is switched off, then the fuel pump is faulty and requires a replacement. In the case of fuel-injected models (2.4L), switch off ignition switch, open fuel tank filler cap, and place battery voltages in the fuel pump check connector, by hearing the whirring sound of the electric pump. To test the pressure of the fuel, squeeze the fuel high-pressure hose and see whether there is any sound; no sound indicates a faulty fuel pump or circuit. Check fuel pressure: To relieve the system pressure, disconnect the negative battery terminal, and reconnect the fuel pump electrical connector. Unscrew the high pressure fuel hose at the delivery pipe and wrap up the point with shop rags to prevent any leakage of fuel. Attach a fuel pressure gauge to the special adapter and connect it to the fuel delivery pipe. Reconnect battery terminal and place battery voltage on the fuel pump check connector, operating the pump and taking care not to leak on the gauge system. Turn on the engine to curb idle speed, use the vacuum hose and connect to the pressure regulator and compare the values. Disconnect the vacuum hose, plug it, test the fuel pressure once more and compare. Turn the engine on and off a couple of times and re-test the fuel pressure to make sure it is steady at idle. When revving the engine, squeeze the fuel return hose to check the fuel pressure; low flow will mean that there is a problem. Readings out of the given values should be checked in the table of troubleshooting to find what has caused it and do repairs. When the engine is switched off, ensure that the fuel pressure gauge reading is not decreasing; otherwise record the rate and consult the troubleshooting table. Lastly, discharge the system fuel pressure, pad the high-pressure hose connection with a towel to absorb any leaks, disassemble the hose, remove the gauge/adapter assembly, attach a new O-ring, reconnect the hose, and screw the screws. Connect battery voltage to the fuel pump post, pump it and verify the high pressure hose against leakages.