Cuts Out, Misses. GMC Truck GMC C Sierra

For 1990-2009 cars only

Makes 🢒 GMC_Truck 🢒 2005 🢒 GMC C Sierra - 2WD 🢒 Engine 🢒 Engine Controls - 6.6L (LLY) 🢒 Cuts Out, Misses

Inspection

Action

DEFINITION: A constant jerking that follows the engine speed, usually more pronounced as the engine load increases which is not normally felt above 1500 RPM or 48 km/h (30 mph). The exhaust has a steady spitting sound at idle, low speed, or hard acceleration for the fuel starvation that can cause the engine to cut-out.

Preliminary Inspection

•	Refer to Symptoms - Engine Controls .

•	Compare the scan tool data at idle with the scan tool data list. Refer to Scan Tool Data List .

Sensor Inspection

•	Observe the fuel rail pressure (FRP) sensor and the fuel pressure regulator commanded percent at idle. The FRP should be near 40 MPa, and commanded percent should be near 40 percent. If the command is high, a fuel pressure or sensor issue exists.

•	Inspect for an intermittent crankshaft position (CKP) sensor signal. Refer to Intermittent Conditions .

•	Inspect the CKP sensor reluctor wheel. Remove the CKP sensor and attempt to move the reluctor wheel front to back or side to side with a probe. If there is any movement the reluctor wheel retaining bolts are loose.

Engine Mechanical Inspection

•	Perform the Engine Compression Test. Refer to Engine Compression Test in Engine Mechanical.

•	Inspect the engine for the following conditions:

-	Improper valve timing

-	Bent pushrods

-	Worn rocker arms

-	Worn camshaft lobes

-	Broken or weak valve springs, refer to Symptoms - Engine Mechanical in Engine Mechanical.

•	Inspect the intake and exhaust manifold passages for casting flash.

Fuel System Inspection

•	Inspect the fuel system for a plugged fuel filter, high vacuum, air in the fuel system, etc. Refer to Fuel System Diagnosis .

•	Inspect for water contamination in the fuel. Refer to Contaminants-in-Fuel Diagnosis .

•	Inspect the fuel injectors for proper operation. Refer to Fuel Injector Balance Test with Tech 2 .