Lack of Power, Sluggishness, or Sponginess

WARNING: This page is about a different car, the 2007 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.

Lack Of Power, Sluggishness, Or Sponginess

Checks	Action
DEFINITION: The engine delivers less than expected power. There is little or no increase in speed when partially applying the accelerator pedal.
Preliminary Checks	Refer to Diagnostic System Check - Vehicle . Refer to Symptoms - Engine Controls . Compare the customers vehicle with a similar unit in order to determine if the customer has an actual condition. Remove the air filter element and check for dirt or restrictions. Check the air inlet duct for any blockage or restrictions. Check the transmission shift pattern and down-shift operation.
Sensor/System	Inspect the throttle actuator control (TAC) system for correct operation. Refer to Throttle Actuator Control (TAC) System Description .
Fuel System Checks	Test for a restricted fuel filter or incorrect fuel pressure. Test the fuel injectors. Perform the following procedures: The Fuel Injector Coil Test-Refer to Fuel Injector Solenoid Coil Test . The Fuel Injector Balance Test-Refer to Fuel Injector Balance Test with Tech 2 . Test for contaminated fuel. Refer to Alcohol/Contaminants-in-Fuel Diagnosis .
Ignition System Checks	Test for the proper ignition voltage output with a J 26792 Spark Tester. Inspect the spark plugs for correct operation and good ignition system performance. Refer to Spark Plug Inspection . Inspect the knock sensor (KS) and the sensor circuit shielding. A faulty knock sensor or signal interference could cause excessive retard of the ignition timing advance. Observe the spark parameter on a scan tool and compare with a known good vehicle.
Exhaust System Checks	Test the exhaust system for a possible restriction. Refer to Restricted Exhaust . Inspect the exhaust system for damaged or collapsed pipes. Inspect the muffler for heat distress or a possible internal failure.
Engine Mechanical Check	Check for any of the following engine mechanical problems: A low compression An incorrect valve timing An incorrect or worn camshaft Refer to Symptoms - Engine Mechanical .
Additional Checks	If the loss of power is above 4,200 RPM, inspect for the correct operation of the rocker arm oil control system. Refer to DTC P2646 . Check the powertrain control module (PCM) grounds for being clean, tight, and in the correct locations. Refer to Engine Controls Schematics . Check the generator output voltage.