The main difference between misfire and backfire is that a misfire occurs when an engine’s cylinder fails to fire (incomplete combustion), whereas a backfire occurs when complete combustion takes place outside the cylinders.
Both misfires and backfires are caused by problems in the engine. Although most of us use these two words as synonyms, there is a difference between misfire and backfire.
Key Areas Covered
1. What is a Misfire
– Definition, Causes, Signs
2. What is a Backfire
– Definition, Causes, Signs
3. Difference Between Misfire and Backfire
– Comparison of Key Differences
Key Terms
Backfire, Misfire, Car, Engine
What is a Misfire
A misfire is the result of incomplete combustion in an engine’s cylinder or cylinders. In a misfire, a cylinder doesn’t produce power. When a vehicle misfires, the driver will feel shaking or hesitation. As the engine misfires, it may vibrate aggressively. Shaking during acceleration, slower acceleration, and brief loss of power are also signs of a misfire. A misfire can happen when the engine is warm or cold; they can also occur intermittently. Sometimes, you may be able to keep on driving (with some difficulty) after a misfire. But some misfires can cause the engine to stop completely.
There can be several reasons for a misfire. To find the exact cause of the misfire, you will have to check the trouble codes in the diagnostics system of the vehicle. In most modern vehicles, the engine light will indicate when there’s a misfire. In the past, spark plugs were the components that mainly caused misfires. This is why most of us still associate misfires with spark plug issues. However, any part of the ignition system (including control module, coil packs, crankshaft position sensor, wiring, and spark plug) can cause a misfire. In addition, problems in air and delivery, emissions equipment, sensor and module, control circuit, and engine mechanical issues can cause misfires.
What is a Backfire
A backfire is a combustion or an explosion that occurs when unburnt fuel in the exhaust system is ignited. Backfires mostly involve a loud popping noise and a flame, followed by a loss of power and forward motion. In the engine’s cylinders’, air and fuel are mixed in a specific ratio at an exact time. The entire mixture is ignited by a spark, and it’s this resulting combustion that powers the vehicle. An engine backfires when the combustion takes place outside the engine’s cylinders.
There are many reasons for engine backfiring. Rich air to fuel ratio, incorrect engine timing, carbon tracking on spark plug wires, and cracked distributor caps are some common causes for backfires.
Difference Between Misfire and Backfire
Definition
A misfire is the result of incomplete combustion in an engine’s cylinder or cylinder while a backfire is a combustion or an explosion that occurs when unburnt fuel in the exhaust system is ignited.
Signs
As the engine misfires, it may vibrate aggressively. Shaking during acceleration, slower acceleration, and brief loss of power are also signs of a misfire. However, backfires mostly involve a loud popping noise and a flame, followed by a loss of power and forward motion.
Cause
A misfire occurs when an engine’s cylinder fails to fire (incomplete combustion), whereas a backfire occurs when complete combustion takes place outside the cylinders.
Conclusion
The main difference between a misfire and a backfire is that a misfire occurs when an engine’s cylinder fails to fire (incomplete combustion) whereas a backfire occurs when complete combustion takes place outside the cylinders. Both of these can be caused by common causes like poor ignition timing, incorrect firing order, faulty equipment, etc.
Reference:
1. “Is Your Engine Misfiring? Here Are 6 Possible Causes.” RepairSmith.
2. “What Causes a Backfire in Your Exhaust.” Midas Service Centre.
Image Courtesy:
1. “Car mechanic fixing an engine cylinder head” By Ivan Radic (CC BY 2.0) via Commons Wikimedia
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