Backfiring during acceleration occurs when ignition takes place in the intake or exhaust instead of the combustion chamber. The most common causes for backfiring during acceleration include an incorrect fuel-to-air ratio, a faulty ignition and bad wiring.
Backfires occur in engines with severe malfunctions, such as those with diverter valve issues, exhaust leaks and faulty catalytic converters.
Backfiring caused by incorrect fuel-to-air ratios result from the engine running with either not enough fuel and too much air or too much fuel and not enough air. These issues result from a damaged fuel filter, low fuel pressure or a weak fuel pump. Backfiring that results from damaged wiring disrupts the ignition’s timing, which causes a build-up of air and fuel in the engine.
Backfiring during acceleration can also be caused by internal carburetor problems, low compression, leaks in the fuel tank, lean engine conditions, and weak or broken valve springs. Backfiring caused by internal carburetor problems is a result of a defective accelerator pump.
An engine backfire is an explosion produced by an internal combustion engine. A backfire results in a temporary loss of power and forward motion along with a loud popping noise. In some cases, a backfire may cause a burst or flame to shoot from the vehicle’s exhaust.