Surges and/or Chuggles

Definition: Engine power variation under steady throttle or cruise. Feels like the vehicle speeds up and slows down with no change in the accelerator pedal.

1. Was the "On-Board Diagnostic (OBD) System Check" performed?

[YES] Go to Step 2.
[NO] Go to OBD System Check. Initial Inspection

2. a. Perform a bulletin search.
b. If a bulletin that addresses the symptom is found, correct the condition as instructed in the bulletin.
c. Was a bulletin found that addresses the symptom?

[YES] Verify repair.
[NO] Go to Step 3.

3. Was a visual/physical check performed?

[YES] Go to Step 4.
[NO] Go to Visual/Physical Check. Visual/Physical Check

4. a. Be sure that the driver understands A/C compressor operation as explained in the owner's manual. Inform the customer how the A/C clutch operates.
b. Is the customer experiencing a normal condition?

[YES] System OK.
[NO] Go to Step 5.

5. a. Check the fuel control Heated Oxygen Sensor (HO2S) (B1S1 and B2S1). The fuel control heated oxygen sensors (HO2S) should respond quickly to different throttle positions. If they don't, check them for silicon or other contaminants from fuel or use of improper RTV sealant. The sensors may have a white powdery coating. Silicon contamination causes a high but false HO2S signal voltage (rich exhaust indication). The Powertrain Control Module ([1][2]PCM) will then reduce the amount of fuel delivered to the engine, causing a severe driveability problem.
b. If a problem is found, repair as necessary.
c. Was a repair required?

[YES] Verify repair.
[NO] Go to Step 6.

6. a. Check the fuel pressure. Refer to Fuel System Pressure Test.
b. If a problem is found, repair as necessary.
c. Was a problem found?

[YES] Verify repair.
[NO] Go to Step 7.

7. Monitor "Long Term Fuel Trim" on the scan tool. Is "Long Term Fuel Trim" in the negative range (rich condition)?

[YES] Go to Step 8.
[NO] Go to Step 9.

8. a. Check items that can cause the engine to run rich. Refer to Diagnostic Aids in DTC P0172.
b. If a problem is found, repair as necessary.
c. Was a problem found?

[YES] Verify repair.
[NO] Go to Step 10.

9. a. Check items that can cause the engine to run lean. Refer to Diagnostic Aids in DTC PO171.
b. If a problem is found, repair as necessary.
c. Was a problem found?

[YES] Verify repair.
[NO] Go to Step 10.

10. a. Check for proper ignition voltage output with the spark tester J 26792.
b. If a problem is found, repair as necessary.
c. Was a problem found?

[YES] Verify repair.
[NO] Go to Step 11.

11. a. Check for a loose ignition control module ground.
b. If a problem is found, repair as necessary.
c. Was a problem found?

[YES] Verify repair.
[NO] Go to Step 12.

12. a. Check the ignition coils for cracks or carbon tracking.
b. If a problem is found, repair as necessary.
c. Was a problem found?

[YES] Verify repair.
[NO] Go to Step 14.

13. a. Remove the spark plugs and check for wet plugs, cracks, wear, improper gap, burned electrodes, or heavy deposits.

NOTE: If spark plugs are gas or oil fouled, the cause of the fouling must be determined before replacing the spark plugs.

b. If a problem is found, repair as necessary.
c. Was a problem found?

[YES] Verify repair.
[NO] Go to Step 14.

14. a. Check the injector connections.
b. If any of the injector connectors are connected to an incorrect cylinder, correct as necessary
c. Was a problem found?

[YES] Verify repair.
[NO] Go to Step 15.

15. a. Check [1][2]PCM grounds for the cleanliness, tightness and proper locations. Refer to the PCM wiring diagrams.
b. If a problem is found, repair as necessary.
c. Was a problem found?

[YES] Verify repair.
[NO] Go to Step 16.

16. a. Check Mass Air Flow (MAF) sensor connections.
b. If a problem is found, replace the faulty terminals as necessary.
c. Was a problem found?

[YES] Verify repair.
[NO] Go to Step 17.

17. a. Visually/physically check vacuum hoses for splits, kinks, and proper connections and routing as shown on the "Vehicle Emission Control Information" label.
b. If a problem is found, repair as necessary.
c. Was a problem found?

[YES] Verify repair.
[NO] Go to Step 18.

18. a. Check the exhaust system for a possible restriction:
- Inspect the exhaust system for damaged or collapsed pipes.
- Inspect the muffler for heat distress or possible internal muffler failure.
b. Check for a possible plugged three~way catalytic converter by checking the exhaust system back pressure.
c. If a problem is found, repair as necessary.
d. Was a problem found?

[YES] Verify repair.
[NO] Go to Step 19.

19. a. Review all diagnostic procedures within this table.
b. If all procedures have been completed and no malfunctions have been found, review/inspect the following:
- Visual/physical inspection.
- Scan tool data.
- Freeze Frame data/Failure Records buffer.
- All electrical connections within a suspected circuit and/or system.
c. If a problem is found, repair as necessary.
d. Was a problem found?

[YES] Verify repair.
[NO] Contact Technical Assistance.