Backfiring during acceleration has become a common issue these days. Generally, the ignition happens in the combustion chamber of the car. Yet, when the same takes place in the exhaust or intake, then it leads to backfiring. If you wonder what causes a car to backfire on acceleration, then a defective ignition or poor wiring could be the probable reason. Besides, an improper fuel-to-air ratio can also make the car backfire.
Further, backfiring occurs quite often in malfunctioning engines. Specific issues such as faulty diverter valve, defective catalytic converters, and leaks in the exhaust are the symptoms of the same. In addition to this, lower compression and lean engine problems contribute to the engine backfiring. If the internal carburetor causes the backfiring, it signifies that the accelerator pump is not functioning correctly.
What happens when the car backfires?
An engine backfiring refers to an explosion generated by the internal combustion of the engine. Thus it causes short-term loss of power along with a frontward motion. In addition to this, the car also produces a loud bursting sound. However, in some conditions, the backfire might instigate the burst or a flame to shoot from the exhaust of the car.
Reasons Due to Which a Car Backfires on Acceleration
Engine backfiring occurs when the mixture of the air-fuel in the vehicle combusts outside the cylinders of the engine. Eventually, it can damage the intake or exhaust of the car if left unresolved or unchecked in long-term use. In the case of backfiring, the car engine would not produce sufficient power, leading to fuel wastage. To know in-depth about what causes a car to backfire on acceleration, go through the following reasons.
Improper Fuel-To-Air Ratios
At times, the engine runs either with lesser fuel and excessive air or too much fuel and insufficient air. Both the conditions can give rise to backfiring due to the incorrect ratios of fuel-to-air.
There can be reasons behind this, such as malfunctioning of the fuel filter, weaker fuel pump, or lower fuel pressure. Moreover, backfiring resulting from the disoriented or damaged wiring unsettles the timing of the ignition. Consequently, it leads to a build-up of fuel and air in the engine of the car.
Poor Ignition Timing
When both sets of valves are properly closed, spark firing will take place in the cylinder. If the timing of the spark is not correct, it could fire it too early, even before the closing of the intake valves. On the contrary, bad or ignition timing can also fire the spark too late, after the opening of the exhaust valves. Because of this, the car will backfire upon acceleration.
Lean Mixture of Air/Fuel
A mixture that lacks a sufficient amount of gasoline can also lead to a backfire. A lean mixture comprises an excessive quantity of air and inadequate fuel. When the fuel pump fails, or there are clogs in the fuel filters or injectors, it lowers the fuel pressure, thereby causing the lean mixture.
Usually, the lean mixture burns very slowly upon the combustion. So there will be some unused fuel and air at the time of opening of the exhaust valves, therefore instigating the backfire.
Inside the cylinders of the engine, there is an intake as well as an exhaust valve. These allow an easy and smooth pass-through of the fuel and air into the cylinders. When the combustion takes place, the valves tend to shut.
After the combustion of the fuel and air, the exhaust valve opens to allow the fumes of the exhaust to pass out through the tailpipe. If any of the valves become bent or twisted, they would not make up for a correct seal. As a result of this, the fuel and air would flow back inside the exhaust or the intake for combustion.
Rich Mixture of Air/Fuel
Sometimes, the fuel injectors leak or the air filter of the engine gets clogged. In both scenarios, there will be more fuel and lesser air in the cylinder. Further, it is necessary to maintain a proper air-to-fuel ratio for good combustion. A mixture of fuel and air containing excessive amounts of gas is known as a rich mixture.
A rich mixture of fuel and air ignites inside the cylinder; the complete mixture would not burn upon the opening of exhaust valves. Afterward, the combustion process would move to the exhaust, thereby resulting in the backfire.
How to Fix the Engine Backfire
After figuring out what causes a car to backfire on acceleration, it is vital to resolve the issue at the earliest. Otherwise, it can damage the engine severely in prolonged use. Below mentioned are the feasible measures to fix the backfire.
Check the Carburetor
A carburetor is a device that aids in regulating the airflow into the engine. Further, it looks after the well-organized gas explosions that keep the car moving along. Firstly you have to tune and stable the carburetor to balance the mixture of the gas and air.
Examine the Distributor Cap
Carefully assess the condition of the distributor cap. If there are any cracks or it is broken, then a backfire can easily take place. Make sure that the distributor cap is in good order, as even a minor crack in the hairline can cause malfunctioning.
Look for the Spark Plugs
Spark plugs are responsible for providing the spark for igniting the mixture of gas and air. If the spark plugs have become dirty or are in bad condition, then backfiring can happen due to the lack of power. To resolve this issue, take out the plugs using a wrench. Ensure that the pins are at the proper distance from the plug’s base.
Besides, keep the gaskets in excellent condition as they help keep the required gases in and the non-required ones out. A backfire can happen if the gaskets are not able to function smoothly.
At times, it becomes difficult to find out what causes a car to backfire on acceleration. However, the aspects mentioned above are the most common causes for an engine backfire. Regularly check the engine light, pressure of the fuel system, airflow sensor, intake tube, vacuum leaks, and camshaft. Ultimately, it would aid you in maintaining the health and functioning of the car’s engine. Not to mention, timely repairs are a must in case if the car backfires. Likewise, it is recommendable to seek professional assistance for the best results.