Mitsubishi Endeavor Bad Fuel Pump: Symptoms, Causes, + Diagnosis

Bad Fuel Pump Symptoms

A bad fuel pump can cause a myriad of problems for your Mitsubishi Endeavor, making it essential to be aware of the warning signs that indicate trouble.

Your fuel pump is responsible for pushing fuel from your vehicle’s fuel tank to the engine, but when it starts to fail, your engine may suffer run rough, have trouble starting, or not start at all.

Mitsubishi Endeavor Bad Fuel Pump

Key Takeaways

  • Be aware of the warning signs of a bad fuel pump, such as a whining noise, stalling, and trouble starting your car.
  • Catching issues early can prevent further damage to your Endeavor and help avoid being stranded.
  • Running low or out of gas can damage a fuel pump and shorten its life.
  • If your Endeavor’s check engine light is on, and it has code P0087, there’s a lack of fuel pressure, and you’re on the right track.


Identifying Bad Fuel Pump Symptoms

Typical Fuel Pump

When determining if your Mitsubishi Endeavor’s fuel pump is going bad, there are a few common symptoms to look out for. Here, we’ll discuss three key indicators that your fuel pump might be failing.

1. Whining Noise

The sound clip above is a fuel pump priming. After it has primed, you may hear a high-pitched whining noise, which can indicate a fuel pump that is failing.

2. Stalling

Another telltale sign that the Toyoat Endeavor’s fuel pump is going out is stalling, often followed by the engine restarting after several minutes. This is due to low fuel pressure.

If you find your car struggling to start or losing power, this could also indicate a fuel pump problem. Long cranking times and the Endeavor running irregularly are other possible indicators of a failing fuel pump.

By being attentive and catching these issues early on, you can address them appropriately and keep your vehicle running smoothly.

3. Engine Sputtering

If your fuel pump is not functioning correctly, you may notice your engine sputtering at high speeds. This happens because the fuel pump is unable to provide a consistent flow of fuel to the engine.

If your Mitsubishi Endeavor is experiencing engine sputtering or cutting out for brief periods, this could be a sign of a bad fuel pump.

4. Power Loss While Accelerating

Another common symptom of a failing fuel pump is a sudden loss of power when you try to accelerate. A properly functioning fuel pump should be able to deliver the required amount of fuel to the Mitsubishi Endeavor’s engine when you step on the gas pedal.

If the fuel pump is failing, it might not be able to keep up with the engine’s demands, causing a noticeable drop in power as you try to accelerate. This power loss is usually temporary but can become more severe as the fuel pump deteriorates.

5. Carortruck Not Starting

A bad fuel pump can also cause your vehicle to have difficulty starting or not start at all. If your Mitsubishi Endeavor struggles to start or dies immediately after starting, ensure you can hear the fuel pump turning on when you first turn the key to the “ON” position.

As mentioned above, a functioning fuel pump will typically make an audible buzzing sound as it primes the fuel lines. If you don’t hear this sound, it could be an indication of a bad fuel pump.

By keeping an eye out for these symptoms, you can quickly identify a potentially failing fuel pump and get it checked or replaced before it causes further issues with your vehicle.

The engine will still crank fine if the starter isn’t engaging; that has nothing to do with the fuel pump.


Causes of Bad Fuel Pump Symptoms: Mitsubishi Endeavor

Worn Fuel Pump (Highly Likely)

A worn fuel pump is likely the reason your Endeavor is experiencing the symptoms associated with low fuel pressure.

Over time, the internal components of your fuel pump wear out, causing it to become less efficient at delivering fuel to your engine. The resultant low fuel pressure can cause those symptoms, such as:

  • Whining noise coming from the fuel tank area
  • Stalling and restarting issues
  • Difficulty starting your vehicle

Fuel Pump Relay Issues

Another potential cause for bad fuel pump symptoms is a faulty fuel pump relay. This relay controls the power supply to your Endeavor’s fuel pump, and a faulty relay may lead to:

  • Intermittent power loss to the fuel pump
  • Inability to start your vehicle
  • Unpredictable pump operation, leading to stalling or rough running

The fuel pump relay will usually not fail when driving. If your Endeavor isn’t starting, and the fuel pump relay isn’t activating, there won’t be any voltage where the fuel pump harness connects to the fuel pump.

You can test the voltage anywhere after the relay to see if power is getting through.

Clogged Fuel Filter

Lastly, a clogged fuel filter can contribute to the bad fuel pump symptoms you may experience. A fuel filter’s primary function is to remove dirt, debris, and contaminants from the fuel before it reaches your engine. A clogged filter can:

  • Restrict fuel flow to your engine, causing a loss of power
  • Contribute to engine misfires and rough idling
  • Put additional strain on your fuel pump, leading to premature wear

Regularly checking and replacing your fuel filter as specified in your vehicle’s maintenance guidelines is essential to maintaining optimal engine performance and avoiding bad fuel pump symptoms.


Seeking Professional Help

Diagnostic Testing

Bad fuel pump Diagnosis

If you suspect that your vehicle has a bad fuel pump, it’s essential to get it checked by a professional mechanic, or take a look at it at home if you’re so inclined. They can perform diagnostic testing to confirm your suspicions and identify the root cause of the problem. Diagnostic testing typically involves:

  • Using an OBD II scanner to check for any relevant code
  • Using a fuel pressure gauge to check your Endeavor’s fuel pressure.
  • Inspecting the fuel filter for any blockages or debris.
  • Examining the fuel lines and connections for any leaks or damage.

By conducting these tests, you or a mechanic can determine if your fuel pump is indeed the issue or if another factor is contributing to your vehicle’s performance problems.

Fuel Pump Replacement

Should the diagnostic tests confirm that your Endeavor’s fuel pump is faulty, you’ll need to have it replaced as soon as possible. Here’s what’s involved in replacing a fuel pump.

  1. Disconnecting the vehicle’s battery and relieving the fuel system pressure.
  2. Accessing your Endeavor’s fuel pump.
  3. Disconnecting the fuel lines and electrical connections from the old fuel pump.
  4. Installing the new fuel pump, reconnecting the fuel lines, and plugging in the electrical connections.
  5. Reinstalling the fuel tank (if removed) or access panel and reconnecting the battery.

Dropping a fuel tank is always easier if you siphon most of the gas out of it first.


Conclusion

In summary, a bad fuel pump can adversely affect your Mitsubishi Endeavor’s performance and potentially lead to expensive repairs or even dangerous driving conditions.

By being aware of the common symptoms, you can take proactive steps to address the issue before it escalates. Among the key indicators to watch for are:

  • whining noise coming from the fuel tank area when the engine is running.
  • Stalling that will restart after several minutes.
  • Trouble starting your Endeavor
  • Lack of power while driving.
  • Long cranking time before the engine starts.