Misfires Archives - UnderhoodService
GM Diagnostic Tip on Misfires, Noises and DTCs

Determine which description best matches the vehicle you are working on, and perform the suggestions as necessary.

Misfire Codes After A Spark Plug Replacement (Video)

After replacing spark plugs, you may get a handful of misfire codes. This video is sponsored by Autolite.

Seasonal Fuel Blends And Misfires (VIDEO)

Here’s what happens when your fuel does not match the weather. This video is sponsored by Standard Motor Products.

Ignition Diagnostics

This part of the cycle is when the mixture of air and fuel ignites and how the flame front spreads in the cylinder.

Seasonal Fuel Blends

The cause of the misfires is the temperature fuel evaporates, otherwise known as the volatility.

Ignition Coil Service: Start To Finish (VIDEO)

Diagnostics depends on the coil’s design and what wires are in the connector. Sponsored by Standard Motor Products.

VIDEO: Curing Common Misfire Codes With Information, Not Parts

Enhanced wiring diagrams let you trace the inputs and outputs for a better diagnosis. This video is sponsored by Mitchell 1.

Freeze Frame Diagnostics

Freeze frame data is a “snap shot” of when the code occurs of the specific sensor PIDs.

Most Common Causes of Intermittent Misfire Codes

Misfires that turn on the check engine light and log a cylinder-specific fault code are the easiest to diagnose.

How Belts, Tensioners And Misfires Are Connected

Modern crankshaft position sensors measure more than the position of the crankshaft.

VIDEO: Misfires In The Ignition System

It is so important to correctly diagnose misfires before repairs. This video is sponsored by Autolite.

Understanding Misfire Events And Causes

Pre-ignition is very damaging because of two dynamics inside the cylinder.