Checks
| Action
|
DEFINITION: Engine
delivers less than expected power. Little or no increase in speed when
the accelerator pedal is pushed down part way.
|
Preliminary Checks
|
| • | Search for service bulletins. |
| • | Compare the customer's vehicle to a similar vehicle. Make sure
the customer's vehicle has an actual problem. |
| • | Inspect the air cleaner filter for dirt or being plugged. |
|
Fuel System Checks
|
| • | Inspect for a restricted fuel filter. |
| • | Inspect items which can cause an engine to run rich (Long Term
FT is significantly in the negative range). Refer to Diagnostic Aids for
DTC P0172 Fuel Trim System Rich
. |
| • | Inspect items that can cause an engine to run lean (Long Term
FT is significantly in the positive range). Refer to Diagnostic Aids for
DTC P0171 Fuel Trim System Lean
. |
|
Sensor/System
|
| • | Test for proper operation of the MAP sensor. |
| • | Test for proper operation of the TP sensor. |
| • | Inspect for a restricted air intake system. |
|
Ignition
System
|
| • | Test for proper ignition voltage output with the J 26792
Spark Tester or equivalent. |
| • | Inspect the spark plugs for the following conditions: |
| - | Burnt electrodes or heavy deposits |
| • | If the spark plugs are fuel or oil fouled, the cause of the fouling
must be determined before replacing the spark plugs. |
| • | Inspect the ignition control module (ICM) for proper ground connection. |
| • | Inspect the ignition coils for cracks or carbon tracking. |
| • | Inspect the spark plug wires for proper resistance and condition. |
|
Engine Mechanical
| Inspect the engine for the following engine mechanical problems:
|
Additional Checks
|
| • | Test the exhaust system for a possible restriction: |
| - | Inspect the exhaust system for damaged or for possible collapsed
pipes. |
| - | Inspect the muffler for heat distress or for possible internal
failure. |
| • | Inspect the vacuum lines for kinks or leaks. |
| • | Test the generator output voltage. Repair the generator if the
output voltage is less than 11 volts or more than 16 volts. |
| • | Test the A/C system operation. The A/C clutch should cut out
at the wide open throttle (WOT) position. |
| • | If all procedures have been completed and no malfunctions have
not been found, review and inspect the following items: |
| - | Visually and physically inspect all electrical connections within
the suspected circuit and/or systems. |
|