1998 Infiniti Q45 BaseFACTORY OEM SERVICE PROCEDURE

Fuel Injector

  1. With engine idling, individually disconnect injector harness connectors. Each injector should produce an equal RPM drop.
  2. With engine cranking or while manually rotating crankshaft position sensor (harness connected with ignition on), listen for clicking or feel for vibration, indicating injectors are triggering. If injectors are not triggering, check power and ground circuits and crankshaft position sensor signal to PCM.
  3. Disconnect fuel injector harness connector. Measure resistance between fuel injector terminals. If resistance is 10-14 ohms, go to next step. If resistance is not 10-14 ohms, replace fuel injector.
  4. Check for injector leaks by removing injector fuel rail. Keep fuel hose and all injectors connected to rail. Turn ignition switch to RUN position. DO NOT  start engine. Observe injector tips for leakage. If injectors drip, replace faulty injectors.
Factory Service Tools

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.

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