Lack of Power, Sluggishness, or Sponginess. GMC Truck Savana 2000

For 1990-2009 cars only

Makes 🢒 GMC_Truck 🢒 2000 🢒 Savana 🢒 Engine 🢒 Engine Controls - 4.3L 🢒 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 Symptoms .

•	Compare the customer's vehicle with a similar unit. Verify the customer concern.

•	Remove the air filter and check for dirt or a restriction.

•	Check the transmission shift pattern and the downshift operation. Refer to Diagnostic Starting Point - Automatic Transmission in Automatic Transmission-4L60-E.

Fuel System Checks

•	Check for a restricted fuel filter, a contaminated fuel, or an improper fuel pressure. Refer to Fuel System Diagnosis .

•	Perform the fuel injector balance test. Refer to Fuel Injector Balance Test with Tech 2 .

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.

Additional Checks

•	Verify that the control module grounds are clean, tight, and in the proper locations.

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

•	Check the torque converter clutch (TCC) operation. Refer to Diagnostic Starting Point - Automatic Transmission in Automatic Transmission-4L60-E.

•	Check the A/C operation. Refer to Air Conditioning (A/C) Compressor Control Circuit Diagnosis .

•	Check the generator output voltage. Refer to Diagnostic Starting Point - Engine Electrical in Engine Electrical.

•	Check the knock sensor (KS) system.

Engine Mechanical Check

Check the engine for the proper operation of the following items:

•	The engine compression

•	The valve timing

•	An improper or worn camshaft.