Backfire. Chevrolet Blazer

For 1990-2009 cars only

Makes 🢒 Chevrolet 🢒 1996 🢒 Blazer - 4WD 🢒 Engine 🢒 Engine Controls - 2.2L 🢒 Backfire

Checks

Action

Definition: The fuel ignites in the intake manifold, or in the exhaust system, making a loud popping noise.

Preliminary Check

Refer to Important Preliminary Checks .

Ignition System Checks

•	Check for the proper ignition coil output voltage with the spark tester J 26792 or the equivalent.

•	Check the spark plugs.

•	Remove the spark plugs.

•	Check for the following items:

Wet plugs

Cracks

Wear

-	Improper gap

-	Burned electrodes

-	Heavy deposits

•	Check the ignition system. Refer to Enhanced Ignition System Diagnosis (Overview) for the 4.3L or Electronic Ignition (EI) System Diagnosis for the 2.2L.

•	Check for crossfire between spark plugs (distributor cap, spark plug wires, and proper routing of the plug wires). Refer to Engine Electrical.

Engine Mechanical Checks

•	Check the engine for the following the items:

-	Engine compression

-	Improper valve timing

-	Intake manifold gaskets, refer to Engine Mechanical.

-	Sticking or leaking valves, refer to Engine Mechanical.

•	Check the EGR operation for being open all the time. Refer to Exhaust Gas Recirculation (EGR) System Diagnosis .

•	Check the intake and exhaust system for casting flash or other restrictions. Refer to Engine Mechanical.

Fuel System Checks

•	Perform a fuel system diagnosis. Refer to Fuel System Pressure Test for the 4.3L or Fuel System Pressure Test for the 2.2L.

•	Perform a fuel injector coil test. Refer to Fuel Injector Solenoid Coil Test for the 4.3L or Fuel Injector Solenoid Coil Test for the 2.2L.

•	Perform a fuel injector balance test. Refer to Fuel Injector Balance Test for the 4.3L Fuel Injector Balance Test .

Additional Checks

•	Check the EGR gasket for a faulty or loose fit.

•	Check the EGR Valve operation for being open all the time. Refer to Exhaust Gas Recirculation (EGR) System Diagnosis .