7 Reasons Why Your Car May Be Misfiring

Do you have a suspicion that your car has begun to misfire? Perhaps you’ve felt a jerk or a stumble while driving as if the car momentarily lost power. This is usually how a misfire is felt.

You may find this sensation more noticeable during high speeds or acceleration, or it may only occur when the engine is idling. It may happen frequently or only occasionally. You may also have noticed increased vibration, increased fuel consumption, or a worrying check engine code may have appeared.

If this sounds like your car, then read on to find out to follow advice from a luxury car repair specialist. They explain what may be causing the misfire and what you should do next.

What can cause engine misfire?

Engine misfires are a common problem because there are several possible underlying causes.

Whatever the cause, a malfunction has affected the engine cylinders’ ability to operate normally. Each cylinder always needs a combination of fuel and oxygen, and a spark to ignite this mix. Take away either the supply of fuel or oxygen or the spark, even very briefly, and one or more cylinders will not fire correctly. The combustion process that powers the car cannot work smoothly.

The most common misfire problems are related to issues with the spark or fuel supply. Here are some of the possibilities:

●      Worn spark plugs

Problems with a part of the ignition system are frequently the cause of misfiring. Spark plugs are a good place to start checking.

Your car will have several spark plugs, one for each cylinder (a regular V6 engine has six, for example). Their job is to deliver the electric current from the ignition system to the cylinder.  Here they ignite the fuel and air mix with a spark.  As they begin to wear, less and less electrical current will reach the cylinder, fail to spark, and misfiring will occur.

These simple parts wear out over time on all vehicles but they are simple and inexpensive to replace. If you consult your owner’s manual, it will probably contain instructions on how often spark plugs need replacing routinely. If you stick to these guidelines, you are far less likely to experience ignition-related misfiring.

Ignition coil problems

The job of the ignition coil is to transform low voltage from the battery into high voltage for the spark plugs.

Ignition systems have changed a lot over the decades, so there are a number of possibilities of how the system might work, depending on the age of the car. You may find your car has a coil for each spark plug or one coil with cables to each spark plug.

Just like spark plugs, ignition coils wear out over time. This makes them a common cause of misfiring problems.

A damaged distributor

The distributor controls the timing of the spark. A broken or cracked distributor cap will stop the signal from going to the spark plugs. If this causes one or more of the spark plugs to fail, then misfiring will likely occur.

Clogged fuel injectors

When fuel injectors get clogged, insufficient fuel will reach the cylinder. This part atomizes fuel and injects it into the cylinder. Interruptions to the fuel supply caused by clogged fuel injectors will cause misfiring.

Clogs can be caused by dirt or debris in the fuel. Your car will have a fuel filter fitted but these can stop performing efficiently over time. Alternatively, there may be rust in the fuel supply system that is contaminating the fuel. Cleaning up or replacing these auto parts is a simple process, so get the needed work done.

A faulty fuel pump

Just like a clogged fuel injector, a defective fuel pump will cause fuel supply issues. The fuel pump sends a high-pressure jet of fuel down the fuel line towards the fuel injectors.

If this part is beginning to fail, the problem may first show itself as a misfiring of the engine.

A defective fuel pressure regulator

This part ensures that fuel is being sent through the engine at the correct pressure. If this is no longer able to give correct readings, then fuel supply issues will occur. This, in turn, may cause misfiring.

Could it be something else?

There are a few other issues that present as misfiring.

Compression in the cylinders can be lost when fuel or air is able to escape before it is ignited. This might be caused by a broken head gasket between two cylinders or a leaky exhaust valve. These problems will cause uneven firing.

More serious mechanical issues will cause misfiring at all speeds. You may also notice strong cabin vibration and even backfiring when the car makes a noise like a gunshot.

Erratic, juddering performance can also be caused by a transmission issue, a problem with the clutch, or the overdrive gear, amongst other things. Car problems may even be caused by a fault in the computer system.

In essence, there are multiple causes of misfiring, some common, others especially rare. It is best to approach a repair specialist for an accurate diagnosis.

Can you drive with a misfire problem?

It’s never advisable to continue to drive a car when you believe it is misfiring. This is because you seriously risk causing further damage to the engine as a side effect of the misfire. At the very least, you may notice a fuel consumption increase.

The best thing to do is to take your car to a repair specialist as soon as possible. They can diagnose the cause of the misfiring and resolve the problem while it’s still simple and straightforward before any serious or costly damage occurs.

Preventing misfiring problems

It’s important to stick carefully to your car’s recommended service and maintenance schedule to prevent worn parts causing misfiring problems.

In addition, as part of your regular maintenance service, it is recommended that you ask your repair specialist to perform two additional engine carbon cleaning services. The first is to add a high-quality injector cleaning additive into the fuel tank. The second is to pour a carbon-removing additive into the intake manifold while the engine runs.

These procedures will help prevent nasty build-ups that are the cause of many misfiring issues.