Section 10 (Engine Controls - 2.6L & 3.2L - Troubleshooting & Diagnosis): Troubleshooting: Surges/Chuggles

WARNING: This page is about a different variant/trim than selected.

Surges/Chuggles

Inspections	Action
DEFINITION: Engine power variation under steady throttle or cruise. Feels like the vehicle speeds up and slows down without a change in the accelerator pedal position.
Preliminary	Refer to Important Preliminary Inspections Before Starting in Symptoms - Engine Controls . Search for bulletins. Inspect the engine control module (ECM) grounds for being clean, tight, and in the proper locations. Refer to Power and Grounding Component Views in Wiring Systems and Engine Controls Schematics . Ensure that the driver understands the operation of the transmission torque converter clutch (TCC) and A/C compressor operation as explained in the owner's manual. Inform the customer how the TCC and the A/C clutch operates.
Sensor/System	NOTE: Refer to Heated Oxygen and Oxygen Sensor Notice in Cautions and Notices. Inspect the heated oxygen sensor (HO2S) wiring for damage and/or poor connections. NOTE: Refer to Silicon Contamination of Heated Oxygen Sensors Notice in Cautions and Notices. Inspect the HO2S for silicon or other contaminants. Inspect the crankshaft position (CKP) sensor and wiring for an intermittent condition. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. Inspect the intake air ducts for proper installation and for leaks. Inspect the mass air flow (MAF) sensor connections. Repair or replace the terminals. Refer to Connector Repairs in Wiring Systems.
Fuel System	Test the Fuel System. Refer to Fuel System Diagnosis . Test for a contaminated fuel condition. Refer to Alcohol/Contaminants-in-Fuel Diagnosis (w/o Special Tool) or Alcohol/Contaminants-in-Fuel Diagnosis (w/ Special Tool) . Verify that each injector harness is connected to the correct injector/cylinder. Relocate injector harnesses as necessary. Test the fuel injectors. Refer to Fuel Injector Coil Test . Test the items which can cause an engine to run rich (long term fuel trim near -13 percent). For a rich condition, refer to DTC P0172 or P0175 . Test the items that can cause an engine to run lean (long term fuel trim near 23 percent). For a lean condition, refer to DTC P0171 or P0174 .
Ignition System	Inspect for proper installation of the ignition coil seal. Improper installation may allow water to enter spark plug area. Inspect for moisture and corrosion. Test for proper ignition system operation. Refer to Electronic Ignition (EI) System Diagnosis . Remove the spark plugs and inspect for the following conditions: Correct heat range Wet plugs Cracks Wear Improper gap Burned electrodes Heavy deposits Determine the cause of the fouling before replacing the spark plugs if the spark plugs are gas, coolant or oil fouled. Refer to Spark Plug Inspection . Once you determine the cause of the fouling, refer to one of the following procedures: For diagnosis of a rich condition, refer to DTC P0172 or P0175 . For diagnosis of coolant contaminated spark plugs, refer to Loss of Coolant (M 35) or Loss of Coolant (M 82) in Engine Cooling. For diagnosis of oil fouled spark plugs, refer to Oil Consumption Diagnosis in Engine Mechanical.
Additional	Visually/physically inspect vacuum hoses for splits, kinks, and proper connections and routing as shown on the vehicle emission control information label. Refer to Emission Hose Routing Diagram . Inspect the exhaust system for the following conditions: Damaged or collapsed pipes Heat distress such as cracking or for an internal failure of the muffler Restricted exhaust-Refer to Restricted Exhaust in Engine Exhaust. Test the transmission TCC operation. A TCC applying too soon can cause the engine to spark knock. Refer to Symptoms - Automatic Transmission in Automatic Transmission. Test the A/C clutch for proper operation. Refer to Symptoms - HVAC Systems - Automatic in HVAC Systems-Automatic.