LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Infiniti >> 1997 >> QX4 >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System & Component Testing 3.3 >> Fuel System >> Fuel Pump System Test
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Fuel Pump System Test

  1. Turn ignition on. With fingers, pinch fuel feed hose at fuel filter. Fuel pressure pulsation should be felt for 5 seconds after ignition is turned on. If pulsation is not felt, go to next step. If pulsation is felt, system is functioning properly.
  2. Turn ignition off. Disconnect fuel pump relay. Fuel pump relay is located in relay box, on right front inner fender panel. Turn ignition on. Measure voltage between ground and fuel pump relay harness connector terminals No. 2 (Black/Yellow wire) and No. 3 (Black/Yellow wire). Battery voltage should be present. If battery voltage is present, go to next step. If battery voltage is not present, check 15-amp fuse No. 17 in fuse box. Check harness continuity between fuses and fuel pump relay. Repair or replace as necessary.
  3. Turn ignition off. Disconnect fuel pump harness connector. Check continuity as follows:
    • Between fuel pump relay harness connector terminal No. 5 (White/Blue wire) and fuel pump harness connector terminal No. 1 (White/Blue wire).
    • Between fuel pump harness connector terminal No. 1 and body ground.

    Continuity should exist in both checks. If continuity exists in both checks, go to next step. If continuity does not exist in either check, repair appropriate harness or connectors.

  4. Check fuel pump relay. See RELAYS  under RELAYS & SOLENOIDS. Also check fuel pump. See FUEL PUMP. If necessary, replace fuel pump relay or fuel pump. If fuel pump relay and fuel pump are okay, disconnect and inspect harness and connectors for pushed-out, bent, damaged or corroded terminals. Repair harness or connectors as necessary.
scientia non olet · About LEMON Manuals