Checks
| Action
|
DEFINITION: Fuel
economy, as measure by an actual road test is noticeably lower than expected.
Also, economy is noticeably lower than it was on this vehicle at one time,
as previously shown by an actual road test.
|
Preliminary
|
| • | Refer to Important Preliminary Checks Before Starting in
Symptoms
. |
| • | Check the owners driving habits. |
| - | Excessive vehicle weight loads |
|
Sensor/System
|
| • | Check the VSS system for proper operation. Refer to
Symptom Diagnosis
in Automatic Transaxle. |
| • | Check the throttle body, TP sensor, and accelerator cables for
proper operation. |
| • | Check the knock system (KS) for excessive spark retard. |
|
Fuel
System
|
| • | Check the fuel injectors. Refer to the following: |
| • | Check for fuel in the pressure regulator. |
| • | Check the minimum idle speed. |
| • | Check for items that cause the engine to run rich. |
|
Ignition
System
|
| • | Check for proper IC circuit connections at each ignition module
assembly. |
| • | Check for proper ignition voltage output using the spark tester
J 26792. |
| • | Check the ignition coils for cracks, or damage. |
| • | Check for a missing or damaged ignition module assembly grounding
spring. |
| | Important: If the spark plugs are gas or oil fouled, the cause of the fouling must
be determined before replacing the spark plugs.
|
| • | Check the spark plugs for the following conditions: |
| - | Incorrect heat range or reach |
| - | Burned or damaged electrodes |
|
Engine
Cooling
|
| • | Check for low engine coolant level. Refer to
Loss of Coolant
in Engine Cooling. |
| • | Check for an incorrect or malfunctioning engine coolant thermostat.
Refer to
Thermostat Diagnosis
in Engine
Cooling. |
|
Engine
Mechanical
|
| - | Sticking or leaking valves |
| - | Broken or weak valve springs |
| - | Excessive oil in the combustion chamber-leaking valve seals |
| • | Check for incorrect basic engine parts. Inspect the following: |
|
Additional
Checks
|
| • | Check the exhaust system for possible restrictions. |
|
