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. |
• | Inspect and compare the customers vehicle to a similar vehicle.
Make sure the customers vehicle has an actual problem. |
• | Inspect the air cleaner filter for dirt or restrictions. |
|
Fuel System Checks
|
• | Inspect items which can cause an engine to run rich--Short
term FT is significantly in the negative range. Refer to Diagnostic Aids
for
DTC P0172
. |
• | Inspect items that can cause an engine to run lean--Short
term FT is significantly in the positive range. Refer to Diagnostic Aids
for
DTC P0171
. |
|
Sensor/System
|
• | Use a scan tool in order to monitor knock sensor (KS) system for
excessive spark retard activity. Refer to
DTC P0325
. |
• | Inspect for proper operation of the manifold absolute pressure
(MAP) sensor. |
• | Inspect for proper operation of the throttle position (TP) sensor. |
• | Inspect for a restricted air intake system. |
|
Ignition
System
|
• | Inspect for proper ignition voltage output with a J 26792
Spark Tester or equivalent. |
• | Inspect the spark plugs for the following conditions: |
- | Improper spark plug gap |
- | Burned 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: |
- | Leaking cylinder head gasket |
- | Worn or a incorrect camshaft |
|
Additional Checks
|
• | Inspect the exhaust system for a possible restriction: |
- | The exhaust system for damaged or for possible collapsed pipes |
- | The muffler for heat distress or for possible internal failure |
• | Inspect the generator output voltage. Repair the generator if
the output voltage is less than 11 volts or more than 16 volts. |
• | Inspect 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
been found, review and inspect the following items: |
- | All electrical connections within the suspected circuit and/or
systems |
|