backfire through intake

What Causes Backfire Through Intake?

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Every part of your engine, like the intake system, is very vital in how your car functions. So, when you have your intake backfiring, it is an issue that you must fix immediately or risk more engine damage. The thing is, many car owners don’t know the engine system to diagnose and fix the problem. 

Having far too much air and not enough fuel will cause a backfire in the intake manifold. Common causes you may notice are Incorrect Timing, Faulty Plug Wires, Leaking Vacuum Hose and Malfunctioning Fuel System. Technicians are usually called upon for such an issue because they understand the intake system well enough to confirm the cause of backfiring and address the issue. Well, if you’d like to know more about backfiring and your intake system, this article is for you.

What Is the Engine Intake Manifold? 

The engine intake manifold can be found on top of V6 and V8 engines. Depending on the number of cylinders, the intake manifold can be installed on the side of the engine. One major component of the intake manifold is the intake valve.

What the intake manifold does is to create a mix of air and fuel in the engine’s cylinders. For this to happen, the intake valve opens to allow gas and air into the engine and closes after to keep the combination trapped in the cylinders. 

Don’t forget, your car engine might experience some damage if you leave the intake system issue unfixed, but it doesn’t cause serious damage. In that case, if there is no damage to your engine, you may not need to replace your intake system. However, parts like the intake valve might require a change if the issue lies with this component of the engine.

Backfiring vs Spitting Differences

One important point to note before we get to the causes of an engine backfiring is to differentiate between ‘spitting’ and ‘backfiring’. Many car owners and even mechanics often assume that both terms are the same. 

Although both terms are car mechanic terminology, they come with their differences, how small they are. Spitting and backfiring are terms used to differentiate between the backfiring within the intake manifold and the carburetor (spitting), and backfiring through the exhaust (backfiring).

Causes of Backfiring Through Intake System

There could be several reasons why the intake system backfires. Whatever the cause, backfiring happens as a small explosion. The intake valve is intended to provide the right balance of fuel and air, and when there’s less fuel than air in the combination, it causes a small explosion. 

This often occurs before the engine gets warm and the accelerator pump doesn’t supply enough fuel. Backfiring in the intake system is usually caused by problems with the ignition timing. However other issues with engine components can cause a backfire.

There are various causes of backfiring through intake:

  • Incorrect Timing 

Your car engine functions efficiently when the spark plugs produce a spark at the right time to ignite the fuel and air mixture. When there’s an issue with the ignition timing, the spark isn’t ignited at the right time, and the fuel gets ignited while the intake valve is still open. This causes an explosion in the intake manifold as the fuel and air mixture to force their exit from the fuel injection intake or the carburetor.

  • Faulty Plug Wires

Ideally, a good plug should endure for a long time in your car. Given that they are the bones of the normal functioning of the engine, spark plugs must be properly installed. However, as a rule of thumb, you should replace your spark plug when your car has run for about 60,000 miles. 

Similar to the ignition timing problem, crossed or wrongly installed spark plug wires can cause the plugs to fire at the wrong time. It causes ignition of the fuel and air mixture while the intake valve is still open, leading to an explosive exit through the carburetor or fuel injection intake. Carb Cleaners can help you with this.

  • Leaking Vacuum Hose

What happens when you have a vacuum hose leak is that it allows excess air to enter the intake manifold. And too much air being mixed with fuel results in a lean running condition. The volatile mix causes premature ignition and causes a backfire.

  • Faulty Computer System

Many modern cars rely on computers to assist in different functions. One of those functions is calculating the fuel and air mixture required in the engine. When there’s a malfunction of one of the sensors used by your onboard computer, the system can misread the requirements and add little fuel to the incoming air, causing a backfire.

  • Contaminated Hotwire 

The function of the mass flow sensor is to read the amount of air that gets into the engine’s intake system. There is a chance that this sensor fails to function optimally when there is a contamination or particle buildup in the hot wire section.

  • Malfunctioning Fuel System 

A bad fuel system can cause your engine to backfire or spit through the intake system. In the event there is an issue with the preset ratio (14:1 air-fuel ratio) of fuel to air in the internal combustion engine, optimum fuel burning is lacking as a result of the inability of the fuel pump to supply the needed volume of fuel to the fuel injectors.

You will also have to check the fuel filter to know if it’s in order. Once the filter is clogged, the amount of fuel passing through it will reduce, leading to an under-supply of fuel.  

backfire through intake

Final Thoughts

Backfiring can be a serious inconvenience and an embarrassing nuisance. The good thing is that most of the causes can easily be taken care of by your mechanic. However, while it may not seem like a serious issue initially, you shouldn’t delay getting your engine looked at. 

That way you may only need to spend a small amount of money fixing the faulty parts, rather than letting the problem get serious that it damages your engine, costing more money to repair. 

Lastly, if you don’t know about working with engine components, do not try to experiment. It can cause you to incur a severe cost. Instead, call a professional to help you look into issues relating to engine backfire through intake.

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