Checks
| Action
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Definition: Engine
delivers less than expected power. Little or no increase in speed when the
accelerator pedal is pushed down part way.
|
Preliminary Checks
|
• | Refer to Visual/Physical Checks
. |
|
Fuel System Checks
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Sensor/System
|
• | Using a scan tool, monitor KS system for excessive spark retard
activity. |
|
Ignition System
|
• | Check for proper ignition voltage output using the following steps: |
- | Clip the spark tester J 26792 to engine ground. |
- | Connect one end of a spark plug wire to the spark tester; leave
the other end of the spark plug wire to the coil being tested. |
- | Connect one end of another spark plug wire to the other coil tower;
connect the other end of the spark plug wire to ground. |
- | Crank the engine while observing the spark tester; a crisp blue
spark should be observed. |
- | Repeat the above steps for each coil. |
• | If adequate spark is not present at the coil(s), check for the
following conditions: |
- | Coil(s) - Cracks, carbon tracking/arcing, or a resistance value
outside the specified range. |
Coil Resistance 5000 - 8000 ohms (5K - 8K ohms) - | Spark Plug wires - Signs of arcing/cross firing, cracks, carbon
tracking, plug boot damage, pinched, improper routing, or a resistance value
outside the specified range. |
Spark Plug Resistance Less than 10000 ohms (10K ohms)
| Important: Spraying the secondary ignition wires with a light mist of water may
help locate an intermittent problem. Ignition components will arc to ground
when a secondary component is faulty.
|
- | Ignition System Wiring - Loose ignition module feed or ground
connection, or damaged system wiring. |
• | Remove spark plugs and check for the following conditions: |
- | Burned or damaged electrodes |
- | Improper heat range or reach |
• | If spark plugs are gas or oil fouled, the cause of the fouling
must be determined before replacing the spark plugs. |
|
Engine
Mechanical
|
• | Excessive oil in combustion chamber-Leaking valve seals.
Refer to Engine Mechanical.
|
• | Low cylinder compression. Refer to Engine Mechanical.
|
• | For incorrect basic engine parts. Inspect the following: |
• | Refer to Engine Mechanical.
|
|
Additional Checks
| Check the exhaust system for a possible restriction.
• | Inspect exhaust system for damaged or collapsed pipes. |
• | Inspect mufflers for heat distress or possible internal failure. |
• | Check for proper TCC operation. Refer to Automatic
Transmission Diagnosis
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