Poor Fuel Economy. Chevrolet Astro

For 1990-2009 cars only

Makes 🢒 Chevrolet 🢒 2000 🢒 Astro - 4WD 🢒 Engine 🢒 Engine Controls - 4.3L 🢒 Poor Fuel Economy

Checks

Action

DEFINITION: Fuel economy, as measured by an actual road test, is noticeably lower than expected.

Preliminary Checks

•	Refer to Symptoms .

•	Inspect the air cleaner element (filter) for dirt or being plugged.

•	Visually and physically inspect the vacuum hoses for splits, kinks, and proper connections as shown on the Vehicle Emission Control Information label.

•	Verify the owners driving habits for the following items:

-	The A/C ON full time (defroster mode ON).

-	The tires for being at the correct air pressure.

-	Excessively heavy loads being carried.

-	Aggressive driving habits.

•	Suggest to the owner to fill the fuel tank and to recheck the fuel economy.

•	Suggest to the driver to refer to Important Facts on Fuel Economy in the owners manual.

Fuel System Checks

•	Inspect the fuel type, quality and alcohol content. Refer to Alcohol/Contaminants-in-Fuel Diagnosis .

•	Inspect the fuel pressure. Refer to Fuel System Diagnosis .

Ignition System Checks

•	Inspect the spark plugs. Remove the spark plugs and check for the following:

Wet plugs

Cracks

Wear

-	Improper gap

-	Burned electrodes

-	Heavy deposits

•	Inspect for an open ignition control (IC) circuit.

•	Inspect the ignition wires for the following items:

Cracking

Hardness

-	Proper connections

•	Inspect the knock sensor (KS) system operation.

Cooling System Checks

•	Inspect the engine coolant level.

•	Inspect the engine thermostat for always being open or for the wrong heat range.

Additional Checks

•	Inspect the transmission shift pattern. Refer to Torque Converter Diagnosis in Automatic Transmission.

•	Inspect for torque converter clutch (TCC) operation. Refer to Torque Converter Diagnosis in Automatic Transmission.

•	Inspect for proper calibration of the speedometer.

•	Inspect for dragging brakes.