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Why Is the Fuel Pump Not Turning On?

Nidhi Nangia
By Nidhi Nangia. Updated: January 16, 2017
Why Is the Fuel Pump Not Turning On?

A vehicle engine system requires continuous fuel supply that is produced through the car’s fuel tank. A fuel pump is required to draw fuel from the fuel tank and propel it into the car’s internal combustion engine. Sometimes, when you turn the key of your car’s ignition system, you notice that the fuel pump does not turn on which means you might have a problem. In this article, we will find out why the fuel pump is not turning on and have a look at what you can do about it.

You may also be interested in: How To Check Fuel Pump Injection Timing
  1. Reason #1: Problematic fuel pump relay
  2. Reason #2: Plugged fuel filter
  3. Reason #3: Bad fuel pressure regulator

Reason #1: Problematic fuel pump relay

The fuel pumps of most vehicles receive their energy via a relay by the powertrain control module (PCM). When you turn on the ignition, the PCM gives energy to the fuel pump relay for a few seconds, so that the pump can run to build pressure. Then, the PCM shuts off the relay, and ultimately the pump, if no rpm signals are received from the engine to indicate starting of the engine after ignition. The circuit for the pump may also be wired through an inertia safety or oil pressure switch, which stops the pump from working in event of an accident. If there is some problem with your car’s fuel pump relay, then it will prevent your fuel pump from turning on. Look into your engine’s compartment in the power center to locate your car’s fuel pump. Remove its relay and give it a good shake. If you feel something rattling inside, then chances are that the relay has broken and you will need to replace it.

Why Is the Fuel Pump Not Turning On? - Reason #1: Problematic fuel pump relay

Reason #2: Plugged fuel filter

The role of a fuel filter is to clean the fuel entering the engine and protect the fuel injectors as well. Over time, it gets clogged and dirty with debris, especially if you leave it for too long without replacement or cleaning. The pressure of fuel entering the engine from the fuel tank gets impeded in case of a plugged fuel filter. In such circumstances, the engine does not receive the fuel required to start and you get an impression that the fuel pump is not turning on. Under severe obstruction, the engine refuses to turn on at all and keeps losing power or cutting out even if it manages to start. So, if that’s the case, get your fuel filter checked and clean it or replace it as required. Click here to know How to Clean Your Fuel Filter.

Why Is the Fuel Pump Not Turning On? - Reason #2: Plugged fuel filter

Reason #3: Bad fuel pressure regulator

A fuel pressure regulator is a device on your vehicle, the main function of which is to build up enough pressure to supply sufficient amount of fuel to the engine. Too much fuel into the fuel injectors can cause them to break down and fail, while too little of it can lead to the fuel pump not turning on. In order to maintain a proper mixture of air and fuel, a proper pressure of fuel is required, which is balanced with the help of a fuel pressure regulator. If your regulator is not working properly, it may lead to too little or too much fuel getting into the engine, due to which the fuel pump may refuse to turn on. If that’s the case, get your regulator checked by a professional and have it fixed or replaced as soon as possible. Fuel entering the engine in inappropriate amounts can be disastrous to your vehicle and potentially to your life if it fails during transit.

Why Is the Fuel Pump Not Turning On? - Reason #3: Bad fuel pressure regulator

If there is anything you are unsure about, it is always best to go see a professional mechanic so that they can best assess the situation. If you are having other car problems, maybe you'll want to take a look at these articles for why is my car jerking? and what does white smoke from my exhaust mean?

If you want to read similar articles to Why Is the Fuel Pump Not Turning On?, we recommend you visit our Car Maintenance and Repair category.

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Why Is the Fuel Pump Not Turning On?