Poor Fuel Economy

Definition: Fuel economy as measured by an actual road test is noticeably lower than expected. Also, economy is noticeably lower than it was on this car at one time, as previously shown by an actual road test.
POSSIBLE CAUSE ACTION
Tires under inflated, brakes dragging or faulty ignition Check and repair as needed.

Restricted air cleaner or exhaust system Check filter and test for restricted exhaust.

Abnormal choke valve operation Check operation and repair or adjust as needed. Choke Adjustments

Vacuum leaks around carburetor base,
intake manifold or vacuum hoses Check and repair or retorque as needed.

Float level or needle valve problem Check adjustment and operation.

Malfunctioning oxygen sensor Check operation and repair as necessary.

Malfunctioning engine coolant temperature sensor Check operation and repair as necessary.

Enrichment valve stuck open Check operation and repair as necessary.

High engine idle speed Check operation and repair as necessary. Curb Idle Speed Adjustment

Malfunctioning slow cut solenoid valve Check operation and repair as necessary.

Malfunctioning throttle position sensor Check operation and repair as necessary.

Malfunctioning engine speed sensor Check operation and repair as necessary.

Broken, short circuited or incorrectly
connected harness connector Check operation and repair as necessary.

Malfunctioning feedback solenoid valve Check operation and repair as necessary.