Canister purge valve:

The EVAP System known as the evaporation emission control system has a very vital part known as the canister purge valve. To prevent the harmful vapors from entering the environment the EVAP system seals the fuel system of your vehicle. The canister purge valve acts as an emission control component that makes it possible to take the exact amount of fuel vapors into the engine intake manifold from the EVA canister.

How does it function?

In modern days the purge valves are controlled by the engine computer and it’s an electrically operated solenoid. The valve will be closed until the engine is off. As soon as it starts running the computer will turn on and will be continuously running, which will moderately open the purge valve. Opening of purge valve allows the vapors to flow from the canister to the engine where the burns. From the EVAP, all parts are connected by a hose.

Location of the Canister Purge Valve:

Typically inside the engine bay, the canister purge value is located. At this location, it is either attached to the intake manifold or the engine. The hose that runs from the intake to the canister often exists on it. In certain types of vehicles, the purge valve can be found near the fuel tank.

Accessing the Canister Purge Valve:

The first thing one should check is on the top of the engine near the throttle body or carburetor. By simply unscrewing it from the engine we can remove the purge valve once it’s located. On the

other hand, one must follow the hoses from the intake manifold if you are finding it difficult to locate.

Before accessing the canister purge valve there are some parts that we might need to move. For example in the case of certain models of vehicles, the canister purge valve is located under the air intake manifold, so before reaching the valve we must disconnect the manifold. On the other hand, instead of beneath the manifold, it exists next to the air intake below and is much easier to access.

Symptoms of a Bad Purge Valve

The issues a vehicle can face while its purge solenoid valve gets stuck open or closed are discussed in detail below.

  • One of the most evident signs is an active check of the engine The engine light gets activated and registers the related DTC trouble codes when the ECU detects the excess or less fuel vapor being released by the valve. However, we still need a mechanic to figure out the actual cause of engine light activation, because it’s the most ambiguous warning light on your dash.
  • EVAP leak also known as a vacuum leak occurs, when a bad purge valve is stuck open. While during the combustion the air-fuel ratio is affected by it and causes a rough idle. Damage in the purge valve solenoid or the vacuum hose attached to it can also occur due to an EVAP leak. Engine oil will stall completely if we ignore a vacuum leak.
  • Staring for a car be difficult when our canister purge valve is This is due to when a stuck open purge solenoid valve creates a vacuum leak. The more air flows inside the

combustion due to the leak, which compromises the combustion process.

  • We experience poor engine performance even if we start our vehicle with a faulty purge valve. While you accelerate the engine will fail to generate enough power.
  • A faulty purge valve will also affect gas mileage and fuel efficiency because of its adverse effect on air-fuel ration combustion.
  • As we discussed above, the canister purge valve is the key component of the EVAP control system, and by preventing harmful hydrocarbons in the gas vapor from leaking out it makes sure that your vehicle meets the emission So we are more likely to fail an emission test once our faulty valve fails to do its job. It increases emission and we can observe it by the excessive black smoke from the exhaust.
  • The fuel tank collapses or deforms when we have a faulty purge valve in our But is a rare phenomenon that occurs in vehicles.
  • If the EVAP purge valve isn’t closing correctly and causing fuel vapor to leak out, we can smell gasoline vapor from your engine.

What Causes the Purge Valve to Go Bad?

Here we will discuss possible causes of a failing canister purge valve

  • Before going into further discussion first, we need to clarify an important concept about the EVAP purge valve and the purge valve solenoid because both are two different For opening and closing the purge valve, the electromagnet solenoid is responsible. So the vapor canister purge valve’s functioning is affected by a faulty solenoid.
  • Malfunctions in the valve can occur due to loose or damaged wiring to the canister purge solenoid. Any loose or damaged wiring to the canister purge solenoid could cause it to malfunction. The canister purge valve can also malfunction due to dirty or corroded
  • Blocking of the purge valve and its functioning can be affected due to fuel deposits, dirt, or normal wear from frequent use of it. How to clean a canister purge valve?
  • A fuel tank won’t be able to maintain the fuel tank pressure due to fuel vapor leak from the valve, also detected by the fuel tank pressure sensor.

How to Test the Purge Valve?

The first step involved in testing the purge valve is to locate it. The steps involved in the testing are given below,

  • Disconnect the electrical battery and let the engine cool
  • For visible signs of damage, inspect the car’s purge valve and its
  • Measure resistance across the valve’s terminal by using a multi-meter to compare it with the specified valve.
  • Turn the ignition on after reconnecting the valve, and try to listen to a humming or clicking sound, if you hear no sound it indicates a faulty valve.
  • A vacuum tester can also be used at one end of the valve to apply the It will build enough pressure to open the valve and allow air to flow through.