Surges/Chuggles

PRELIMINARY CHECKS
^ Perform the careful visual checks as described at start of "Symptoms".
^ Be sure driver understands transmission torque converter clutch and A/C compressor operation as explained in the owner's manual.

ADDITIONAL CHECKS
^ CHECK: PCM grounds for being clean, tight and in their proper location.
^ CHECK: Vacuum lines for kinks or leaks.
^ CHECK: Generator output voltage. Repair if less than 9 volts or more than 16 volts.
^ CHECK: Speedometer display with the reading on a Tech 1 scan tool are equal.
^ CHECK: Service Bulletins for updates.

SENSORS
^ CHECK: Heated Oxygen Sensor (HO2S). The Heated Oxygen Sensor (HO2S) should respond quickly to different throttle position. If it does not, check the Heated Oxygen Sensor (HO2S) for silicon or other contaminations from fuel or improper use of RTV sealant. The sensor may have a white, powdery coating and result in a high but false signal voltage (rich exhaust indication). The PCM will then reduce the amount of fuel delivered to the engine, causing a severe driveability problem. Also, watch for green (glycol) contamination or cracking.

IGNITION SYSTEM
^ CHECK: For proper ignition voltage output using spark tester (ST-125) J 26792 or equivalent.
^ CHECK: Spark plugs. Remove spark plugs, check for wet plugs, cracks, wear, improper gap, burned electrodes, or heavy deposits. Repair or replace as necessary. Also, check spark plug wires.

FUEL SYSTEM

NOTICE: To determine if the condition is caused by a rich or lean system, the vehicle should be driven at the speed of the complaint. Monitoring long term and short term fuel trim will help identify a problem.

Lean - Long term fuel trim above 150. Refer to "Diagnostic Aids"Powertrain Controls - ECM/PCM of Diagnostic Trouble Code (DTC) 44.

Rich - Long term fuel trim below 110. Refer to "Diagnostic Aids"Powertrain Controls - ECM/PCM of Diagnostic Trouble Code (DTC) 45.

^ CHECK: Fuel pressure while condition exists. Use CHART A-7Related Tests, Information and Procedures.
^ CHECK: In-line fuel filter. Replace if dirty or plugged.