What causes a car to back fire when accelerating?

Answer by  Joe77 (24)

The simple answer to the question is unburnt fuel igniting in the exhaust system. When the vehicle is running "rich", exhaust gas leaves the combustion chambers loaded with unburnt fuel. As a result, there is a tendency for this mixture to ignite in the exhaust and create a "pop" or backfire. Bad sensors or ignition components are usually the culprits.

Answer by  sc773 (79)

What actually is happening is that an explosion is occurring in the exhaust system (or the intake) and not where it's supposed to be: in the engine. An incomplete or premature burn of the fuel is happening. This can happen with bad fuel or a timing issue delivering the fuel to the engine. (Spark plugs, intake valve)

Answer by  noey1958 (1405)

This happens alot when your plugs are misfiring in an older vehicle. You may need new spark plugs or you may need new wires. This could also be caused by a wire being loose or the contact with the wire is not tight. Bad gas(with water in it) may cause this also.

Answer by  tylerj72993 (21)

A car will backfire when accelerating if there is a bad spark plug usually. When accelerating and a spark plug misses it causes extra gas in the engine which causes it to backfire. A easy fix to this problem is to replace your spark plugs. This should fix your problem

Answer by  djones (4)

no loss of power but truck misses and backfires when accelerating have replaced plugs and wires, and fuel filter and o2 sensor

Answer by  Anonymous

i have a 99 taurus and just changed the plugs and its still when u put it in gear bogging down n backfires then kicks in till i give it alot of acceleration can somebody plz give advice

Answer by  vuick (3)

new plugs and wires truck hesitates while accelerating and backfires. 99 tacoma 2. 7 could it be the coil pack? code pulled misfire # 1 cylinder