Fuel Pump Regulator

Projections show that the global fuel pump delivery system market will reach a value of $27.2 billion by 2026.- Fuel Pump Regulator

One important component of a car’s fuel delivery system is the fuel pump regulator. When a regulator fails it can lead to a number of larger problems. It is important to know how to tell when a fuel pump regulator has failed so that you can replace it with a new one.

For a rundown of signs that you need to replace a fuel pump regulator, keep reading.

What Is a Fuel Pump Regulator?

A fuel pump regulator is a component that regulates both the fuel pressure and the amount of fuel that goes to the injectors in a direct injection system.

A combustion chamber requires the correct mix of fuel and air to work at maximum efficiency. If a fuel pump regulator is not functioning properly it can make the mixture too rich (too much fuel) or too lean (too much air). 

Symptoms of a Bad Fuel Pump Regulator

Various signs may indicate a faulty fuel pump regulator. If you notice any of the following you should have a professional look at your car to clarify the problem.

Engine Misfiring

One of the most common fuel pump regulator problems that occur is engine misfiring either while idling or accelerating. This can create a fairly distinctive sputtering noise, or sometimes just an unusual noise during acceleration.

As this can be caused by several other things, you shouldn’t replace your fuel pump regulator immediately, but instead, have a mechanic take a look at your car first.

Weak Acceleration

If your fuel pressure is off, it can affect your acceleration. To maintain stable performance the fuel mixture needs to be correctly balanced.

If the fuel mixture is too rich or too lean it can have the same result: a drop in acceleration.

Check Engine Light

Modern cars have many sensors which help keep things running and detect any issues. These are usually observed with a monitoring system, so when a sensor fails repeatedly, it will indicate this to you.

If the fuel pressure sensor detects that the fuel pump regulator has failed it will show the check engine light on your dashboard. This light could come on due to various issues, so again should be checked by a professional to confirm the problem.

Black Smoke From Exhaust

Black or grey smoke from your exhaust can be the result of several issues. One reason could be a bad one creating a mixture that is too rich.

If you notice this along with any of the other symptoms listed in this article then your it is more than likely the issue.

Fuel Leak

One of the most urgent issues with a fuel pump regulator that could occur is a fuel leak. This can cause performance issues and lets off a bad smell, but more importantly, presents a safety risk.

A fuel leak can lead to a fire, so if you notice one you should have it taken care of as soon as possible.

Black Spark Plug

Another thing that can come as a result of a rich mixture is excess soot in the combustion chamber. This may be noticeable on spark plugs, as they can end up coated in soot.

In this case, you will need to replace it as well as the spark plug.

Gasoline in Vacuum Hose

Sometimes the vacuum system can be affected by a faulty one, and gasoline may fill the hose. The vacuum hose has a connection to it, so disconnect it here and check inside the hose to see if any fuel has got inside.

Gasoline Smell on Dipstick

This is something that can take some time, so may occur if you drive for a long duration with a bad one. After a long drive, remove the oil dipstick and check to see if it smells of fuel. If so, the cause may be the regulator.

A Drop In Milage

When a bad one creates a lean mixture it can affect the overall performance of your car. On top of a drop in acceleration, it can also cause a drop in mileage.

Over time this can cause increased damage to your car, so it’s not something you should ignore.

Engine Backfiring

A bad fuel pressure pump might cause excess fuel to flow through the lines. The engine won’t be able to combust this excess fuel, making the exhaust system overfill.

Heat in the exhaust system can ignite this fuel, which will make the loud banging noise of a misfire. In some situations, this can make the exhaust pipe explode, and start a fire, so you want to have this dealt with as soon as you notice it.

Diagnosing a Bad Fuel Pressure Regulator

A fuel pressure gauge is one of the best ways to diagnose a problem with it. It can detect whether or not the regulator is regulating the line pressure correctly.

Newer vehicles can usually be checked more easily by using an OBD2 scanner. These don’t always give completely accurate results, so if you suspect your this is faulty you should double-check it manually.

If you aren’t too knowledgeable about cars and aren’t fully confident checking the fuel pump regulator yourself, you should get a professional to do it. This may be better if you notice any of the symptoms above, as the problem might be caused by something else, which a professional mechanic should be able to determine.

If you find the fault and need to replace a fuel pump regulator, this is something that you may also want to get a mechanic to do if you are not confident carrying it out yourself.

Fuel Pump Regulator Repairs

A fuel pump regulator is generally not an expensive part, but when faulty it can cause various issues. If you notice any of the symptoms above you should check it out as soon as you can to avoid further problems.

If you’re interested in more tech and lifestyle articles, check out some of our other blog posts.