Fuel Injector Balance Test With Tech 2: Description

WARNING: This page is about a different car, the 2003 GMC Sierra, 2003 GMC Cab & Chassis Sierra, 2003 Chevrolet Silverado, and 2003 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

The Fuel Injector Balance Test is performed when a misfire, knock, excessive smoke, or rough running condition exists with no electrical Diagnostic Trouble Codes (DTCs). During the test the ECM turns off individual injectors while engine is running and scan tool displays engine RPM. If a fuel injector is turned off and there is a different engine speed change observed on the scan tool when compared to the other cylinders, that cylinder has a fuel injector or engine compression condition. If there is a balance rate of more than 4 mm³ or less than -4 mm³ on any of the cylinders, that cylinder has a fuel injector or engine compression condition. If a fuel injector is turned off and engine noise or smoke disappears, that cylinder has a fuel injector or engine compression condition.