Why Car Won’t Start After Changing Spark Plugs

A car won’t start after changing spark plugs only when you have not correctly installed new ones. Either you’ve damaged a part while removing the old plug, or the mounting process was wrong.

So, how to fix this blunder? Should you go back in time using a time machine to do it over? Well, you can if you have a time machine! But if you don’t have a time machine, I would recommend to read this article thoroughly.

What Went Wrong While Removing Old Spark plugs?

To quickly remove dead plugs from the cylinders, you might’ve damaged a thing or two like fuel circulators. Or, you could’ve also thrown away a few mandatory wires with the old plug. Several things can happen here, but let’s focus on the common ones.

• Old plugs can stay jammed inside the cylinder. Reverse torquing them forcefully can damage the torque spirals of inputs. That’s why the new ones inserted might’ve been a bit loose.
• Bad ignition could cause carbon and oil on spark plugs. So, despite removing worn-out spark plugs, the carbon fouls can still remain and block the new ignition system. Putting the new plugs inside without cleaning the inputs is another big mistake.
• Disconnecting ignition coils and wires is the first step of the replacement process. If somehow any wires or pins get impaired, they won’t work properly. Using them with a new sparking plug is of no use.

Possible Mistakes in Putting a New Spark Plug

Inserting a new plug isn’t like twisting it inside and done. You have to be careful about the placements, connections, compatibility, etc. Novice DIY guys mostly forget these facts.

• Sparkers kept loose can’t ignite the fuel well. Reasons behind loose plug may be either you’ve used anything except torque or socket wrenches to tighten, or you don’t know how much to torque.
• Multi-coiled engines likely have separate coils for every one or two ignitor plugs. Attaching a coil’s wire with the wrong sparker doesn’t complete the ignition system route.
• Forceful installation can also break firing pins or ceramic coatings, resulting in a broken sparker that prevents the engine to start.
• Recently, the most common reason spotted is trying to fit incompatible plug models in an engine cylinder. Car engines can’t run with misfits. This issue occurs when you don’t check the engine and purchase anything popular.

What If None of the Things Above Happened?

In every case, flawless spark plug changing would stop a car from starting. Surely, there are some other problems inside your car that have appeared now. Don’t let your thoughts run around sparking plugs all the time.