Changed Spark Plug Wires Now Car Won’t Start (Why & How To Fix)

Spark plug wires are likely to last for a long time. In most cases, they can easily last over 60,000 miles before you can think of replacing them. 

Most people do not experience problems with their spark plug wires, but when this happens, it could require replacing the wires. 

Assuming that you have replaced the spark plug wires, all that is left is to start the car and drive. But wait, the car does not start. At this point, you need to troubleshoot to understand why this is the case and fix it. 

Why the Car Won’t Start After Changing Spark Plug Wires (7 Reasons)

1. Lose spark plug wires

Sometimes you would get people fitting the spark plug wires loosely. This is not something you would want to do especially for something sending power to the spark plugs. 

Depending on the type of car, some might have connectors. Ensure that you hear the connectors clicking into place. This assures you that the spark plug wires are not tightly fitted. 

There are others where the coil and spark plug wire is the same. For this case, ensure that the coil is pushed tight into the spark plug well to hold onto the spark plug correctly. This helps the spark plug fire correctly each time

Do the same thing for the distributor side. This will leave you with a strong connection that ensures the car can start correctly. 

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2. You have connected them in the wrong order

It might not seem like something a person might do, but it happens. 

Let us assume you have removed several plug wires from their position and when it comes to replacing them, you forget where to reconnect them correctly. 

If the spark plug wires are connected in the wrong firing order, then you might end up with a problem starting the car. It is best to mark the firing order and have the spark plug wires replaced correctly. 

Some people take pictures and videos so that they have an easier time identifying where the spark plug wire came from. 

3. Using the wrong spark plug wires 

Each car model would have specific performance capabilities thus the reason to use the correct spark plug wires. 

It would be nice to consult your owner’s manual for more details or talk to a pro. This helps to always buy the right spark plug wires from an auto shop. 

Here is a video to help in changing the spark plugs and wires

YouTube video

4. The spark plugs are worn or faulty 

This is another thing you have to check while changing the spark plug wires. Sometimes might find it is actually the spark plugs that have issues and not the plug wires. 

Remove the spark plugs individually to see where there could be an issue. If there are signs of carbonation, broken firing pins, or any other fault, change the spark plugs to get the car running

We recommend that you use spark plugs meant for your car to avoid any more troubles with starting the car. 

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5. The ignition coil has no spark 

The work of the ignition coil is to deliver the electrical pulses to the spark plugs which in turn fire and run the car. If there is power flowing through the ignition coil, then you will have a hard time starting the car. 

Make sure that you can test each coil to see if it gets power. In case you have faulty coils, replace them and continue using the coil with no issues. 

6. The fuel filter is clogged

If the fuel filter is clogged or the fuel pump is not working, then the engine would not get the fuel it needs to start. This is a common problem if you keep running the car on an empty tank. 

The car ends up with a clogged filter or a burned fuel pump. 

Turn on the car and listen for the fuel pump to jump into action. In case there is no fuel coming to the engine, the solution is to replace the fuel pump. 

Here is a video on identifying symptoms of a failed fuel filter

YouTube video

7. Dead car battery 

This should also be among the first things you keep in mind especially if it is an old battery. It is estimated that a car battery may last five to six years. 

The good thing about a faulty battery is that it will show symptoms for several weeks before it fails completely. So, you can easily replace it or eliminate it as the reason why your car is not starting. 


Can a faulty MAF sensor make the car not start?

Yes. This sensor is important for ensuring there is the right amount of air-fuel mixture in the engine. If it is not working correctly, then you can have too much fuel with no air or vice versa. 

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What is the correct firing order for a car?

Connecting the spark plug wires in the right firing order is quite important. Consider referring to the car manual to understand the correct firing order as it can vary from model to model.

Can you replace only one spark plug wire?

It is possible to replace just one spark plug wire if it is the one that has a fault. Sometimes you can replace them all if they are older. 

Is it expensive to replace spark plug wires?

It depends on the car and labor costs. The whole process can cost an average of $200. If you know how to do it, you can save a lot of money. 

Can you drive with a faulty spark plug wire?

It can be possible to do so sometimes. However, the engine might not run smoothly. You would notice that the engine keeps misfiring.

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