What You Need to Know About Engine Misfires


What You Need to Know About Engine Misfires

Engine misfires can be very frustrating, the symptoms from each vehicle varies but it’s generally described as a stumble or momentary reluctance in power delivery. An engine misfire can be continuous or temporary and most times, it will generate a check-engine code.

What is an engine misfire?

Let’s talk about what causes a misfire. We all know that an engine requires three mechanisms to fire a cylinder: Fuel for ignition, oxygen to burn the fuel, and a spark to ignite them both. Once you take out one of the mechanisms, the cylinder will not function properly. That sounds easy, right, however, incorrect ignition timing, valve spring wear and vacuum leaks are other causes of cylinder misfire.

If you have a misfiring engine, locate the problem and fix it ASAP. Misfires can increase emissions and decrease mileage which in turn can make you fail an emission test. Bear in mind that cylinder misfires can damage other engine parts such as catalytic converter and the oxygen sensors. Here are the things you need to do while diagnosing this problem.

When it’s the spark

The ignition parts that are responsible for the sparks to an engine are wear parts that have been designed to offer maximum performance for their service life, and be changed as needed. Once these parts wear out, there will be little or no electricity to ignite the spark plug. Since this occurs over time, you’re going to have little misfires that you may not notice and gradually, with time it will get worse. That’s a sign that the ignition system is the cause of your misfire.

Spark plugs are inexpensive and can be changed within a few minutes. Old Ignition wires that have worn out can easily be replaced too. Old vehicles that have a traditional distributor may require a new cap rotor. The modern vehicle coil packs are reasonably priced and can be serviced by our expert team.

When it’s the fuel

Once the ignition system has been checked, move to the fuel system, it’s possible that the fuel injectors are dirty or that the filter is clogged. If they are ok, take a look at the mass airflow sensor or the fuel pump because they may have worn out.

The EGR valve may fail with age, thus allowing exhaust to get to the intake manifold. The emissions Systems are specifically designed and you’re going to have issues if you have spent exhaust in the wrong area of the ignition cycle. Or perhaps, you’re lucky to have loaded up a tank of bad gas.

Your fuel system misfire signals will abruptly appear and can be very evident when the engine is idle compared to when it’s running and on a highway. If for any reason, your engine is gulping at a stoplight but great at speed, check the fuel system.

When the engine misfire is a mechanical problem

Engine misfires can be complex, go over the vacuum lines linked to the intake manifold. Check for cracks and replace lines should you discover any issues. Also take a look at the state of the intake manifold gaskets, particularly around the throttle body. Take a timing light beneath the hood to ensure that the timing belt or chain has not jumped or slipped. Lastly open a valve cover and check the valve train for any damage.

Nothing like the fuel misfire indications, mechanical misfire signs will not vanish while speeding, it often gets worse. The misfire issue can cause obvious vibrations in the cabin, or even backfires. At this point, your engine’s PCM ought to reveal a code.

Check engine light explained

The “Check Engine” light indicator is your vehicle’s way of notifying you of a fault with the vehicle, One amazing thing is that, diagnostic codes are straight to the point, sometimes it can tell you which cylinder is faulty. Try to always use a code reader because it speeds up the fault finding process.

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