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What Causes A Car To Backfire On Acceleration?

Have you ever faced backfiring in the engine? Do you know what causes a car to backfire on acceleration? The backfire is generally a malfunctioning in the internal environment of the combustion engine. It deals with multiple issues and problems which need to correct within a time limit to prevent severe damage to the car. Here, in this article, we will deal with specific essential points related to the backfiring in the engine. So, we hope the answer you are searching for or the desired result regarding the topic reaches you as per your requirement.

Thus, let’s begin with the matter and have a detailed description of the crucial points.

What Does Backfire Mean?

The backfire can cause ignition with the open exhaust valve or unburnt fuel making its way into the hot exhaust system. A visible flame may momentarily shoot out of the exhaust pipe, resulting in the backfire signifying the engine is improperly tuned.

What Causes A Car To Backfire On Acceleration?

An engine faces backfire whenever the air-fuel mixture in your car combusts somewhere outside the engine’s cylinder. However, there are various reasons responsible for the generation of backfire in the vehicle during acceleration.

Some of the most common causes regarding the topic are listed below:

1. Bent Valve Or Valves

The car engine consists of an engine cylinder, which has two valves, one is an intake valve while the other is an exhaust valve. These valves are designed to allow the entry of both air and fuel into the cylinder, which later shut down when combustion occurs. As soon as the combustion of the air and fuel is completed, the exhaust valve opens and allows fumes via the tailpipe.

Thus, whenever these valves are damaged, face any malfunctioning or become bent, the purpose or function of the valves is not fulfilled, causing the modern car to backfire. It is one of the reasons for causing reverse in the engine while accelerating.

2. Rich Air-Fuel Mixture

It is often observed in vehicles and considered one of the careless methods for generating issues. After all, it is caused due to too much fuel added to the cylinder. It is a case similar to the leaking fuel injector or clogged engine air filters.

The combustion occurring in any place or vehicle must carry out a proper air-fuel mixture to avoid any issues. Whenever a wide air-fuel variety ignited in the cylinder, the whole mix won’t burn out completely, and the exhaust valve opens, causing a backfire in the engine.

These situations generally deal with the replacement or fixation of a bad fuel injector, bad mass airflow sensor, or maybe just an air filter.

3. Bad Ignition Timing

There is a generation of spark inside the cylinder, which favours specific movement in the vehicle. However, this spark initiates only after the closing of both the valves in the engine’s cylinder. Hence, you could relate that the fault in valves results in another issue, i.e., improper or inadequate ignition timings in the vehicle.

The condition would result when the spark occurs either too early or occurring late than the purposed time. It may cause the air-fuel mixture in the exhaust or intake to combust during a rough time. Hence the vehicle face backfires whenever accelerated.

Nowadays, the control system responsible for maintaining the spark is all computer-based. Thus, it is necessary to visit the technician for the issue to avoid other problems.

4. Lean Air-Fuel Mixture

Along with the rich air-fuel mixture, the lean air-fuel mixture causes such issues in the vehicle. The poor mix is generally a ratio or combination with low fuel and excess air in the engine’s cylinder. Thus, the mixture doesn’t have enough gasoline, causing a backfire in your car.

The low level of fuel in the vehicle generally caused due to a failing fuel pump, a dirty fuel filter, or a clogged fuel injector. It is better to consult a professional regarding the matter as it involves certain crucial parts of the system.

5. Cracked Distributor Cap

Cars with distributor caps in spark plugs are responsible for the generation or initiation of the problem. In such cases, if the cap faces any malfunctioning or cracks, then it would allow moisture to creep in, resulting in an electrical spark to jump to the wrong cylinder. Thus, causing a backfire.

Can Backfire Damage An Engine In Car?

The backfiring and after engine can cause engine damage, power loss, and decrease fuel efficiency. There are a variety of factors, as mentioned above, which are responsible for backfire in the machine. However, the most common elements of the issue include poor air to-fuel ratio, a misfiring spark plug, or good old-fashioned wrong timings.

How To Fix The Backfiring In Engine?

The fixation of backfiring in the engine must perform as soon as possible. Hence, the issues related to the system won’t extend much and cause damage to the vehicle. It includes specific steps which must follow sequentially to fix the damage.First of all, check the engine light and then check the fuel system pressure. Depending on and analyzing the pressure, replace the mass airflow sensor. Soon after it, prevent the air intake boot and vacuum leaks. At last, check the worn spark plugs as well as the camshaft.

Thus, this will help you fix the engine backfiring and solve your problems to the maximum extent.

Frequently Asked Questions:

So,here are some of the frequently asked questions about Can A Bad Fuel Pump Cause a Backfire? Can Bad Spark Plugs Cause Backfire etc?-

Can A Bad Fuel Pump Cause Backfire?

A bad fuel pump, vacuum leak, or clogged fuel injectors could cause an air-fuel ratio that’s too lean; that is, it has too much air and this is the opposite problem, it can also cause a backfire as vapor escapes into the exhaust.

Can Bad Spark Plugs Cause Backfire?

A cause of your backfire is a spark plug refusing to “spark” when the exhaust valve opens. If the fuel mixture has become too rich, unburned fuel is left in the exhaust system. The misfired spark plug ignites  and in loud in the tail pipe.

How Do I Stop My Engine From Backfiring?

There are things you can do to prevent your car from backfiring-
  1. Change oxygen sensors and renew that spark.
  2. Check engine belts.
  3. Keep a healthy exhaust.

What Causes is Backfire While Driving?

The spark inside the chamber may not burn up all the fuel, leads to extra gasoline vapour entering the exhaust, and lead to a backfire. This can be caused by a mass airflow sensor or a clogged engine which is a faulty air filter in the engine and not allowing enough oxygen.

Why Does A Car Backfiring Sound Like Gunshots?

If the air mixture has become too rich, unburned fuel, The misfired spark plug ignites the rich air mixture, causing a loud in the tail pipe.


We hope the information mentioned earlier guides and helps you deal with the unstable situations of backfiring in the car. Hence, we also expect that you are well aware of fixing and knowing what causes a car to backfire on acceleration.

If your doubts or queries regarding the topic persist, we request you to please comment below in the comment section. Thus, we’ll try our best to answer all your questions as quickly as possible.