No.14 Poor Fuel Economy: Notes

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POOR FUEL ECONOMY - DESCRIPTION AND POSSIBLE CAUSE

14	Poor fuel economy
DESCRIPTION	Fuel economy is unsatisfactory.
POSSIBLE CAUSE	Contaminated air cleaner element IMCC malfunction Engine cooling system malfunction Improper ATF level Weak spark Poor fuel quality Erratic or no signal from CMP sensor Improper coolant level Inadequate fuel pressure Spark plug malfunction PCV valve malfunction Brake dragging Improper valve timing due to jumping out of timing belt Contaminated MAF sensor Improper engine compression Exhaust system clogging WARNING: The following troubleshooting flow chart contains the fuel system diagnosis and repair procedures. Read the following warnings before performing the fuel system services: Fuel vapor is hazardous. It can easily ignite, causing serious injury and damage. Always keep sparks and flames away from fuel. Fuel line spills and leakage are dangerous. Fuel can ignite and cause serious injuries or death and damage. Fuel can also irritate skin and eyes. To prevent this, always complete "BEFORE REPAIR PROCEDURE" and "AFTER REPAIR PROCEDURE" described in this manual. (See BEFORE REPAIR PROCEDURE .) (See AFTER REPAIR PROCEDURE .)

Poor fuel economy

DESCRIPTION

Fuel economy is unsatisfactory.

POSSIBLE CAUSE

Contaminated air cleaner element
IMCC malfunction
Engine cooling system malfunction
Improper ATF level
Weak spark
Poor fuel quality
Erratic or no signal from CMP sensor
Improper coolant level
Inadequate fuel pressure
Spark plug malfunction
PCV valve malfunction
Brake dragging
Improper valve timing due to jumping out of timing belt
Contaminated MAF sensor
Improper engine compression
Exhaust system clogging
WARNING:
- The following troubleshooting flow chart contains the fuel system diagnosis and repair procedures. Read the following warnings before performing the fuel system services:
  - Fuel vapor is hazardous. It can easily ignite, causing serious injury and damage. Always keep sparks and flames away from fuel.
  - Fuel line spills and leakage are dangerous. Fuel can ignite and cause serious injuries or death and damage. Fuel can also irritate skin and eyes. To prevent this, always complete "BEFORE REPAIR PROCEDURE" and "AFTER REPAIR PROCEDURE" described in this manual.
    (See BEFORE REPAIR PROCEDURE .)
    
    (See AFTER REPAIR PROCEDURE .)