Surges and/or Chuggles
Checks
| Action
|
DEFINITION: The engine has a power variation under a steady throttle
or cruise. The vehicle feels as if it speeds up and slows down with no change
in the accelerator pedal.
|
Preliminary Checks
|
| • | Be sure the driver understands the A/C compressor operation. |
| • | Use a scan tool to make sure the reading of VSS matches vehicle
speedometer. This excludes vehicles with electronic transmissions where some
variation between VSS and the speedometer is normal. |
|
Sensor Check
| Check the Heated Oxygen Sensor (HO2S) Sensor 1 and Sensor
2 performance. Refer to DTC P0131 through DTC P0141 Diagnostic Aids.
|
Fuel System Checks
|
| • | Check if a Rich or Lean system can cause the condition. Drive
the vehicle at the speed of the complaint. Monitoring the Fuel Trim may help
identify the problem. |
|
Ignition System Checks
|
| • | Check for the proper secondary voltage output with a spark tester
(J 26792 or equivalent). |
| • | Check the spark plugs for any of the following conditions: |
| - | Wet (fuel fouled) plugs. |
| - | A terminal screw that is bent or loose (rotate and pull). |
| - | A ceramic insulator that has cracks, carbon tracking or deposits
(red or black dust) |
| - | A tip insulator that has cracks, carbon tracking, deposits (oil,
carbon, glazing, fuel additive), or is loose (rattles). |
| - | A center electrode that is loose (wiggles side to side) |
| - | An incorrect spark plug gap that is too large or too small. |
| - | Platinum pads that are missing. |
|
Additional Checks
|
| • | Check the PCM grounds for being clean, tight, and in their proper
locations. Refer to PCM Wiring Diagrams. |
| • | Check the generator output voltage. |
| • | Check the vacuum lines and hoses for kinks or leaks. Refer to
the Vehicle Emission Control Information label. |
|
