Calculation of Basic Injection Duration

The first step in determining how much fuel to deliver to the engine is calculation of basic injection duration. Basic injection duration is a function of:

• Long fuel trim (LFT) correction factor

This basic injection duration value is the ECM's best guess at the actual injection time necessary to achieve an ideal air/fuel ratio. Generally, this basic injection calculation is very accurate, typically within ± 20% of what actual injection needs to be. Once within this range, the ECM can trim the air/fuel ratio to stoichiometry based on oxygen sensor information.

Do It Yourself Car Diagnosis

Do It Yourself Car Diagnosis

Don't pay hundreds of dollars to find out what is wrong with your car. This book is dedicated to helping the do it yourself home and independent technician understand and use OBD-II technology to diagnose and repair their own vehicles.

Get My Free Ebook

Post a comment