Circuit/System Testing
WARNING: This page is about a different car, the 2007 GMC Sierra, 2007 GMC Cab & Chassis Sierra, 2007 Chevrolet Silverado, and 2007 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
IMPORTANT:
- You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.
- A fuel injector leak into the combustion chamber may result in mechanical damage to the cylinder. If any fuel spray comes out of a glow plug hole during the compression test, replace the fuel injector of the affected cylinder.
Perform the engine compression test. Refer to Engine Compression Test .
- If the compression indicated any of the cylinders had low compression, refer to Symptoms - Engine Mechanical .
- Failure to correctly identify the cylinder positions may result in the replacement of the wrong injector.
- During replacement of the injectors, inspect the inlet and outlet fittings for corrosion or contamination. Refer to Contaminants-in-Fuel Diagnosis .
- If the engine did not have low compression on any of the cylinders, replace the fuel injectors on the cylinders that had low cylinder power contribution, high balance rates, or a noise/smoke change during cancellation.
IMPORTANT: