Misfires Archives - Page 2 of 2 - UnderhoodService
VIDEO: Diagnosing Ignition Related Misfires

By performing these easy checks, you can determine if the spark plug wires are the problem or it is another component in the ignition system or on the engine. Sponsored by Blue Streak.

VIDEO: How Misfire Codes Get Set

Andrew Markel discusses misfire codes, and how the camshaft and crankshaft position sensors detect rotational anomalies to set them. Sponsored by Auto Value and Bumper to Bumper.

GM Tech Tip: Cold Start Misfires

An owner may complain of misfire or roughness during a cold start. Also, a P0300 code might be present, or there may be misfire codes limited to one or two cylinders. Looking at the misfire counter on a scan tool, you will see a high rate on typically one cylinder. The cause of the misfires might be a coolant leak that allows coolant to enter the cylinder at the point where the liner meets the deck face cast.

Misfires In The Crankshaft And Camshaft

Any time you’re dealing with a combustion engine, there’s a chance it will develop a misfire. A better understanding of how computer systems analyze a misfire can make your job that much easier as the service tech.

Hyundai Fuel System And Emissions Diagnostics

Bob Dowie recently had a 2002 Elantra GLS in the shop. This vehicle is a good example of some common fuel trim and emissions problems you’ll see.

Most Common Causes of Misfire Codes

A flashing check engine light and a P0301 to P0312 diagnostic trouble code (DTC) is a surefire indication that one or more cylinders are misfiring. Occasional misfires may pass unnoticed, but a steady misfire is hard to miss. The engine usually feels rough, lacks power and uses more gas than usual. Sometimes a misfire may

Spark Plug Worn Rings