How to Test High Pressure Fuel Pump? Definitive Guide

High-pressure fuel pumps have evolved into an essential component of the fuel processing system. Since the emergence of rapid fuel injection, high-pressure pumps have also been employed in petrol engines.

A defective high-pressure fuel pump can cause mechanical damage. That’s why you should know how to test the high-pressure fuel pump.

This article will help you to find useful information and valuable tips on all aspects of high-pressure fuel pumps work, and you will learn the testing method of high-pressure fuel pumps also.

High Pressure Fuel Pump- Everything you need to know

A fuel pump is a part of a motor vehicle that circulates liquid from the fuel tank to the engine’s carburetor, internal combustion, or fuel injector.

For the engine to run properly, the fuel pressure must be within certain limits. If the fuel limit is exceeded, the engine will run harsh and rich, failing to consume all of the fuel being pushed, keeping the engine inefficient and polluting. On the other hand, the engine may run lean, misfire, or stall if the pressure is too low.

The high-pressure fuel pump, in combination with the low-pressure fuel pump, is responsible for delivering gas from the tank to the vehicle’s engine. A high-pressure fuel pump failure can have a massive impact on your vehicle’s performance.

Know- How To Test High Pressure Fuel Pumps

There are some steps to follow in testing high-pressure fuel pumps. They are as follows…

Step 1: Safety First

Consider fuel pressure and flow testing on a return fuel delivery system. Before you start doing any diagnostic testing, keep in mind that releasing petrol under pressure might result in a fire and injuries. So prioritize safety. Wear safety glasses and gloves, operate in a well-ventilated place, and avoid smoking or having anything that might spark.

Step 2: Check the fuel pressure

First, make sure the fuel pressure is right. Start the car and allow it to idle for a few moments. Install a fuel pressure gauge, turn on the pump, and take a reading. Then, compare it to the specifications provided by the manufacturer. If the pressure is too low, you should take care of it. If the fuel pump is producing enough pressure, run a fuel volume test to see if the correct quantity of fuel is reaching the fuel injectors.

Step 3: Measure using a flowmeter or a glass measuring container.

A flowmeter is the most accurate technique to test fuel delivery. However, although some repair shops may have it, you may not. So there you have it: a rather dependable method for doing a timed fuel delivery test. Be cautious and use an adequate measurement container. Because gasoline may corrode or fog up plastic, glass is a suitable alternative.

Step 4: Put it to the test

Starting the car will indicate the pump to start, so start it and let it idle. You must obtain a fuel sample for five seconds while the pump is operating. The pump should supply a specified amount of gasoline within that time frame—check your manufacturer’s specifications to determine if your pump is providing the correct amount and if your system is functioning properly. You might have to convert milliliters per second to gallons per hour to find it out.

Reasons why high-pressure fuel pumps aren’t working

Symptoms of a high-pressure fuel pump failure:

• Engine start-up is delayed.
• Acceleration stalling or sputtering between 2000 and 4000 RPM
• Engine temperatures are high.
• Vehicle stalls as a result of exercise or temperature
• Low readings on the fuel pressure gauge
• Gas mileage is poor.

When the engine does not get enough fuel from the fuel pump system, or when the fuel is delivered at an improper pressure, it is unable to maintain engine combustion. This eventually leads to engine failure, with the engine stalling or failing to start at all. This might be a symptom of fuel pump breakage, aging, or even blockage of the system. If you are not first alerted to the problem by the mentioned symptoms, your check engine light will blink and may be indicative of the circumstances described.

Tips to keep last longer the high-pressure fuel pump

The high-pressure fuel pump is designed to last around ten years or 120,000 miles. Unfortunately, the high pressure fuel pump can fall at any time. Still, there are a few things you can do to help the high-pressure fuel pump last longer.

Change your oil regularly

Many people put off oil changes for as long as they can since symptoms are not always obvious. However, a lack of appropriate oil changes will eventually result in fuel pump damage. Inadequate lubrication from suitable oil levels creates friction in crucial systems, harming the fuel pump and needing maintenance. A decrease in lubrication from the oil can also result in growing heat levels, a sign that might lead to resistance of the fuel pump motor and, eventually, system failure.

Pay close attention to the quality of the fuel

The type of fuel you use has an impact on the life of your vehicle and critical systems. According to research, “top-tier” gas with detergent additives is ideal for your engine, allowing it to not only operate smoothly but also keep the engine clean.

Keep your fuel tank from becoming too low

Running the fuel tank low is another typical practice that might cause irreparable harm to the fuel pump. Although it may appear to be a small maintenance issue, not having enough fuel in the tank may expose your fuel pump to extreme heat, causing it to fail. Furthermore, the weight of the fuel is a significant component in the fuel system’s capacity to carry the fuel from the gas tank to the engine. Therefore, not enough fuel will hinder its functioning.

Final words

As the car ages, the mechanical components of the fuel pump can fail, resulting in a loss of pressure to the fuel injection rail and injectors, resulting in difficulty starting, hesitation, and poor engine power, and when the pump’s internals fail altogether, the engine will not start.

To avoid safety issues and engine power loss, high-pressure fuel pumps must be tested. I hope the above steps will help you to test high-pressure fuel pumps.

Related Post:

1. You may also like some of the high-pressure and high-volume pumps.

2. Check out our guide to reattaching the gas pump hose.

3. Our guide to how to check the power steering pump.