Lack of Power, Sluggishness, or Sponginess. Pontiac Vibe

For 1990-2009 cars only

Makes 🢒 Pontiac 🢒 2004 🢒 Vibe - AWD 🢒 Engine 🢒 Engine Controls - 1.8L (LNK) 🢒 Lack of Power, Sluggishness, or Sponginess

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 - Engine Controls .

•	Refer to Symptoms - Engine Controls .

•	Compare the customers vehicle with a similar unit in order to determine if the customer has an actual problem.

•	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 mass air flow (MAF) sensor operation. Run the engine to normal operating temperature. Turn OFF all accessories and observe the MAF sensor at idle with a scan tool. If the MAF sensor reading is more than 3.5 g/s refer to DTC P0101 .

Fuel System Checks

•	Check for a restricted fuel filter or incorrect fuel pressure.

•	Check the fuel injectors. Perform the following procedures:

-	The Fuel Injector Coil Test--Refer to Fuel Injector Solenoid Coil Test - Engine Coolant Temperature Between 10-35 Degrees C (50-95 Degrees F) or to Fuel Injector Solenoid Coil Test - Engine Coolant Temperature Outside 10-35 Degrees C (50-95 Degrees F) .

-	The Fuel Injector Balance Test--Refer to Fuel Injector Balance Test with Special Tool .

•	Check for contaminated fuel. Refer to Alcohol/Contaminants-in-Fuel Diagnosis .

Ignition System Checks

•	Check 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 .

•

Check 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. A typical value at 98 km/h (60 mph) with all engine accessories off is 26-32 degrees.

Exhaust System Checks

•	Check the exhaust system for a possible restriction. Refer to Restricted Exhaust in Engine 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 Diagnostic Starting Point - Engine Mechanical in Engine Mechanical-1.8L (LNK).

Additional Checks

•	If the loss of power is great above 6,000 RPM, inspect for the correct operation of the Rocker Arm Oil Control system. Refer to DTC P1012 .

•	If there is a slight loss of power at WOT, inspect for the correct operation of the Auxiliary Intake Air Control system. Refer to Auxiliary Intake Air System Diagnosis .

•	Check the powertrain control module (PCM) grounds for being clean, tight, and in the proper locations. Refer to Engine Controls Schematics .

•	Check the generator output voltage.