When diagnosing engine problems, particularly a "no start'' condition, the fuel pump function should be checked. Because of the difficulty in reaching the fuel pump connections, Mitsubishi automobiles have a conveniently located test connector under the hood. V6 Monteros have the connector taped to a wiring harness inside the right front kick panel, near the ECM and relays.
This connector bypasses all of the controls in the system (ignition switch, pump relay, etc.) and sends voltage directly to the pump. When power is applied to the pump you should be able to hear it running, although the in-tank pumps require you remove the fuel filler cap and listen at the filler.
To use the test connector, make certain the ignition is OFF. Great damage may be caused if the system is tested with the key on. Locate the test connector in the engine compartment (on later Monteros it is located under the right-hand side of the dashboard) — it is generally on a short lead out of a wiring harness and looks like a plug that isn't connected to anything. Once found, use a jumper wire to connect the test terminal to the positive battery terminal. Listen for the fuel pump; if it runs, you know the pump motor is good. While the pump is running, gently squeeze one of the fuel lines and confirm that the pump is delivering fuel pressure. If it does not run, the pump itself is most likely defective OR the connector to the pump is faulty.
When the pump is removed from the tank, it may be checked by applying battery voltage (+) to the connector and grounding the housing. Only run the pump for one or two seconds during this test; the pump can be damaged by running without liquid.
CAUTION
Make certain the pump has been drained of residual fuel and is free of fuel
vapors. Connecting and removing the test leads will cause sparks which can ignite
any vapor in the area.
Additionally, the pump motor may be checked with an ohmmeter. Some resistance should be seen on the meter scale. If the meter shows no motion (infinite), the motor has an internal fault and the pump must be replaced.