Black Smoke Coming From Your Tailpipe? One Reason Why & How To Fix It

Driving should be a carefree endeavor, but it can be alarming when you see unexplained signs of trouble, like black smoke coming out of your tailpipe. Black smoke is usually related to excess gasoline in your engine that was not burned correctly, which might be caused by a bad fuel pressure regulator. The following guide will help you diagnose your issue and help you fix it, as long as you have the right piece of equipment and tools.

What Does The Fuel Pressure Regulator Do

The regulator is a small device resembling a hexagon that usually sits on the driver's side (under the hood on the back wall). The fuel pressure regulator senses how much power your vehicle needs and allows the exact amount of gasoline needed for your engine. The regulator also determines the correct air-to-gas mixture that is needed for proper combustion. The fuel pressure regulator helps to keep excess fuel out of your system as well.

Signs Of Trouble

One of the most obvious signs of a bad fuel pressure regulator is black smoke coming out of your tailpipe. This happens because your exhaust gets contaminated with excess fuel. You may even notice this smoke when your vehicle is just sitting idle. The following are other signs related to a bad fuel pressure regulator:

  • You might see bad fuel economy due to the excess fuel being used
  • Fuel may drip from the fuel hose connected to the regulator
  • Your plugs may look grimy
  • There may be some gasoline dripping from your tailpipe
  • Engine might stall
  • The oil dipstick might smell like fuel

Talk to your auto care specialist about these symptoms, so that he or she can tell you if your suspicions are correct.

Fixing Your Issue

You can attempt to replace the regulator on your own, but you will need the following:

  • Your owner's manual or repair guide
  • Socket and wrench set
  • Petroleum jelly
  • New fuel pressure regulator that matches your car, which can be purchased from a local company such as Parts Chain
  • Rag
  • Safety goggles and gloves

Follow the steps below to replace the regulator:

  1. Park your vehicle in a safe location and on level ground.
  2. Let the vehicle cool down enough so that you can work on it easily.
  3. Put on your safety goggles and gloves.
  4. Locate the fuse box, and disconnect the fuel pump relay.
  5. Disconnect your red or negative cable from the car battery for your safety.
  6. Locate the regulator, which is a hexagon-like device that sits on the back wall under your hood. Disconnect the hose and cable from the regulator.
  7. Use your socket and wrench set to remove the bolts holding it in place, then remove it.
  8. Clean the area, and lube the new regulator's o-ring with your jelly.
  9. Install your new regulator, and reconnect the hose and cable.
  10. Reconnect the fuel pump relay, then connect your battery cable back. Try your vehicle out, and hopefully this resolved your issues.

Remember that you can have your auto care specialist deal with the replacement of this piece should you feel uncomfortable doing it on your own.