A bad fuel pressure regulator is a fairly common problem that can pop up over the life of a vehicle. It can leave your car or truck inoperable and can be difficult to diagnose without the right tools.
Most modern vehicles have the fuel pressure regulator mounted on the fuel rail. Some may be in the fuel pump assembly, but this is rarely the case (although it is happening more and more).
Fuel Pressure Regulator Cost
If you think that you may need a fuel pressure regulator for your vehicle, they are relatively affordable.
Fuel pressure regulators in general are easy to get to, although the difficulty reaching them will vary by the vehicle, model year, and the engine equipped.
Before purchasing a new fuel pressure regulator, it’s a good idea to check and make sure that it’s the part that you need to fix your vehicle. The symptoms of a bad fuel pressure regulator are similar to a bad fuel pump or bad fuel filter.
What a Fuel Pressure Regulator Does
Your vehicle’s fuel pressure regulator controls the pressure of the fuel before it hits the fuel rail. Keeping consistent pressure to the fuel injection system is vital to the efficient operation of any engine. It properly controls the amount of fuel entering the fuel injectors, intake, and combustion chamber.
Think of it like a damn with a river of fuel behind it. It also saves wear and tear on the injectors themselves. Too much fuel pressure can ruin them.
Bad Fuel Pressure Regulator Symptoms: vehicle
A bad fuel pressure regulator can put your vehicle out of commission. Here are a few of the most common symptoms of a bad fuel pressure regulator:
- Misfire– When the fuel pressure regulator fails, it can allow too much or too little fuel into the engine. Either way, this wreaks havoc on the air fuel mixture. Without a proper air/fuel mixture, the engine may run rough, misfire, hesitate, or fail to start at all.
- Leaking Fuel– If any of the seals in the fuel pressure regulator fail, or if the diaphragm fails, raw fuel will begin to leak. Beside the loss of power and fuel economy that this can cause, it’s a big safety hazard. Most of the time, when there is a fuel leak, it’ll be accompanied by the sharp smell of gasoline.
- Black Exhaust Smoke– One of the most common symptoms of a vehicle that has a bad fuel pressure regulator is that it’ll run rich. The tell tale sign of a vehicle that is running too rich is that it’ll have black exhaust smoke.
- Decreased Fuel Economy– With the engine not running at optimal efficiency (and potentially dumping raw fuel) fuel economy will definitely suffer.
Conclusion
If you have most of the symptoms listed above, you may have a bad fuel pressure regulator. The next step is going to be testing it to see if it holds pressure, and if so, the right amount of pressure.
Here’s a really great writeup from AxleAddict on exactly how to go about testing your vehicle’s fuel pressure regulator.
If there is anything that you would like to add, please feel free to leave a comment below.