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2017 Lexus IS 300 Long Cranks and Stalling - Fuel System?

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Chris P. · rep 0 · May 22, 4:40 AM · 1 replies · solved · Question

Vehicle: 2017 Lexus IS 300 AWD

Hi everyone, I'm reaching out because my 2017 Lexus IS 300 AWD has been acting up lately. For the past few weeks, I've noticed that it takes much longer to start, especially after the car has been sitting for a while. It cranks for several seconds before finally catching.

Even more concerning, the engine has stalled on me twice while driving at low speeds, once pulling into a parking spot and another time at a stop sign. There's no check engine light on right now, but I'm getting worried. I also thought I heard a faint whining noise from the rear of the car a few times, which might be related.

Could this be a fuel pump issue or something else with the fuel system? What should I be looking at for a 2017 IS 300?

✓ Accepted solution

ClearTheCode Admin

ClearTheCode Team · rep 0 · May 22, 4:40 AM

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ClearTheCode admin answer:

Long crank times and stalling in your 2017 Lexus IS 300, especially when accompanied by a whining noise from the rear, are strong indicators of a potential issue within the fuel delivery system. The absence of a check engine light doesn't mean there isn't a problem, as some fuel pressure issues might not immediately trigger a DTC.

Common Causes:

  1. Failing Fuel Pump: This is the most likely culprit. A fuel pump that is weakening will struggle to build and maintain adequate fuel pressure, leading to long cranks and potential stalling. The whining noise you described is a classic symptom of a failing fuel pump working harder than it should.
  2. Clogged Fuel Filter: While many modern Lexus vehicles have the fuel filter integrated into the fuel pump assembly, a severely clogged filter can restrict fuel flow, mimicking a failing pump.
  3. Fuel Pressure Regulator Issues: The fuel pressure regulator maintains consistent fuel pressure. If it's faulty, it can cause either too high or too low pressure, leading to starting and running problems.
  4. Leaking Fuel Injectors: If one or more fuel injectors are leaking, fuel pressure can bleed off when the car is off, leading to long cranks as the system needs to re-pressurize. This can also cause a rich condition and rough running.
  5. Fuel Pump Relay: A faulty fuel pump relay can intermittently cut power to the fuel pump, causing stalling or preventing it from priming correctly.

What to Do:

  1. Listen for the Fuel Pump Prime: When you first turn the ignition to the 'ON' position (before starting), listen carefully for a brief hum or whirring sound from the rear of the car. This is the fuel pump priming. If you don't hear it, or it sounds weak/intermittent, it's a red flag.
  2. Check for Pending Codes: Even without a CEL, a professional scan tool might reveal pending codes related to fuel pressure, such as P0087 (Fuel Rail/System Pressure - Too Low), P0088 (Fuel Rail/System Pressure - Too High), or P0191 (Fuel Rail Pressure Sensor Range/Performance).
  3. Professional Fuel System Diagnosis: A technician will perform a fuel pressure test at the rail to confirm if the pump is delivering adequate pressure. They can also check the fuel pump's current draw and inspect the relay.

When to See a Shop:

Immediately. Stalling while driving is a significant safety concern. A failing fuel pump can leave you stranded. Have your Lexus IS 300 inspected by a qualified mechanic or Lexus dealership as soon as possible to prevent further issues and ensure your safety.

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