GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2002 🢒 Astro - 2WD 🢒 Engine 🢒 Engine Controls - 4.3L 🢒 Lack of Power, Sluggishness, or Sponginess

Inspections

Action

DEFINITION: The engine delivers less than expected power. There is little or no increase in speed when partially applying the accelerator pedal.

Preliminary
    • Refer to Symptoms - Engine Controls .
    • Compare the customer vehicle with a similar unit. Verify the customer concern.
    • Remove the air filter and inspect for dirt or for a restriction. Refer to Air Intake System Description .
    • Verify the transmission shift pattern and the downshift operation. Refer to Diagnostic Starting Point - Automatic Transmission in Automatic Transmission.

Fuel System
    • Inspect for a restricted fuel filter, contaminated fuel, or improper fuel pressure. Refer to Fuel System Diagnosis , Alcohol/Contaminants-in-Fuel Diagnosis , or Fuel Pressure Gage Installation and Removal .
    • Perform the fuel injector balance test. Refer to Fuel Injector Balance Test with Tech 2 .

Exhaust System

    • Inspect 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
    • Inspect the control module grounds for being clean, tight, and in their proper location.
    • Inspect the torque converter clutch (TCC) operation. Refer to Diagnostic Starting Point - Automatic Transmission in Automatic Transmission.
    • Inspect the A/C operation. Refer to Air Conditioning (A/C) System Performance Test in HVAC.
    • Inspect the generator output voltage. Refer to Diagnostic System Check - Engine Electrical in Engine Electrical.

Engine Mechanical

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

    • Engine compression--Refer to Engine Compression Test in Engine Mechanical.
    • Valve timing
    • Improper or worn camshaft--Refer to Camshaft and Bearings Cleaning and Inspection in Unit Repair.