For 1990-2009 cars

## Surges/Chuggles Petrol

Checks | Action
--- | ---
DEFINITION: The engine has a power variation under a steady throttle or cruise. The vehicle feels as if speeds up and slows down with no movement of the accelerator pedal.
Preliminary Checks |

• | Refer to Important Preliminary Checks in Symptoms - Engine Controls .

• | Ensure the vehicle operator understands the transmissions torque converter clutch (TCC) operation, if equipped.

• | Ensure the vehicle operator understands the A/C compressor clutch operation, if equipped.

Sensor Checks |

• | Test for correct operation of the vehicle speed sensor (VSS).

• | Test for correct operation and performance of the oxygen sensor.

Fuel System Checks |

• | Inspect for a lean or rich engine condition.

| Using a scan tool observe the oxygen sensor output while operating the vehicle under the symptom condition.

• | Test for correct fuel system pressures. Refer to Fuel System Diagnosis .

• | Inspect for correct operation of the LPG fuel injectors. Refer to:

| Fuel Injector Balance Test with Special Tool

• | Make sure that the manual shut-off valve is fully open.

• | Inspect for restricted LPG lock-offs or filter. Refer to and Fuel Filter Replacement .