Testing for a Faulty Fuel Pressure Regulator

A faulty fuel pressure regulator is going to cause a lot of hesitation in your vehicle. The engine can give out excessive oil or smoke as a sign of a faulty regulator. It affects fuel mileage because it tampers with the fuel-injection system, which is used to adjust the amounts of air and fuel received by the engine. Low pressure is the most common way for a regulator to fail so that’s always a good indication that something is wrong with it. The fuel pressure regulator has a hose that provides a vacuum that is set right next to it. When the vehicle is in idle the hose provides less pressure to the fuel coming inside. When the engine is revved the pressure increases. A faulty regulator tampers with this pressure and fuel is not properly served to the engine.

Fuel regulators are part of the fuel-injection systems of modern engines, along with other components, such as the fuel pump, control module and various sensors. Having any of these components fail can affect the entire injection system. This is one of the main reasons the regulators fail, as they are otherwise very reliable. Fixing them is usually done by replacing the entire part, as they do not have a high cost.

Known Locations of a Regulator

When you’re trying to locate your fuel pressure regulator you have to know where to start looking. This will be different for different cars. The easiest way to find it is to follow the fuel rails. The regulator will have a vacuum line attached to it that looks a lot like a vacuum cleaner’s hose. The actual regulator is small in size, usually made of metal and looks like something you would use to uncork a bottle of wine. It is held in place by a built-in thread and is usually screwed in.

Symptoms of a Faulty Regulator

The symptoms of a faulty fuel pressure regulator are varied and can be shared by other problems with your car. The most common is having a rough engine, even while in idle. This can cause the engine to run erratically or come to a complete stop. It is also referred to as stalling. Smelling the oil dipstick is a good way to detect it, as well. If you smell fuel on it then it is a sign that you have fuel infiltration in the oil bath. This typically points to a faulty regulator. Black smoke coming from the tail pipe is another symptom, although this can be a symptom for other problems as well, such as low oil or bad air/fuel mixture.

Safety Information

Whenever you are working on car components that come in contact with fuel or electricity it is a very good idea to remove the battery terminals. Rogue sparks can ignite fuel vapors without even coming in contact with the actual fuel. When working with the regulator it is also good practice to disconnect the fuel pump relay. Check the owner’s manual whenever you are unsure of what you are doing and wear protective gear such as glasses and gloves when working with the fuel pressure regulator.