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Home >> Isuzu >> 2004 >> Axiom Base, 4WD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - Diagnostic Information & Procedures >> Symptom Diagnosis >> Surges and/or Chuggles Symptom

Surges and/or Chuggles Symptom

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.

SURGES AND/OR CHUGGLES SYMPTOM

Step Action Values Yes No
1 Was the "On-Board Diagnostic (OBDII) System Check" performed? - Go to Step 2 Go to On-Board Diagnostic (OBD-II) System Check
2 Was the "Electric Throttle Control (ETC) System Check" performed? - Go to Step 3 Go to On-Board Diagnostic (OBD-II) System Check
3
  1. Perform a bulletin search.
  2. If a bulletin that addresses the symptom is found, correct the condition as instructed in the bulletin.
Was a bulletin found that addresses the symptom?		 - Verify repair Go to Step 4
4 Was a visual/physical check performed? - Go to Step 5 Go to VISUAL/PHYSICAL CHECK 
5 Be sure that the driver understands transmission torque converter clutch (TCC) and A/C compressor operation as explained in the owner's manual.
Inform The customer how the TCC and the A/C clutch operate.
Is the customer experiencing a normal condition?		 - System OK Go to Step 6
6
  1. Check the fuel control heated oxygen sensors (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 silicone or other contaminants from fuel or use of improper RV sealant. The sensors may have a white powdery coating.

    2. Silicon contamination causes a high but false HO2S signal voltage (rich exhaust indication).

  2. The ECM will then reduce the amount of fuel delivered to the engine, causing a severe driveability problem. For more information, refer to Engine Control Module (ECM) Diagnosis .
  3. If a problem is found, repair as necessary.
Was a problem found?		 - Verify repair Go to Step 7
7
  1. Check the fuel pressure. Refer to Fuel System Check (High Pressure Line) or Fuel System Check (Low Pressure Line) .
  2. If a problem is found, repair as necessary.
Was a problem found?		 - Verify repair Go to Step 8
8 Monitor the long term fuel trim on the Tech 2.
Is the long term fuel trim significantly in the negative range (rich condition)?		 - Go to Step 9 Go to Step 10
9
  1. Check items that can cause the engine to run rich. Refer to Diagnostic Aids in DTC P0172 Diagnostic Support.
  2. If a problem is found, repair as necessary.
Was a problem found?		 - Verify repair Go to Step 11
10
  1. Check items that can cause the engine to run lean. Refer to Diagnostic Aids in DTC P0171.
  2. If a problem is found, repair as necessary.
Was a problem found?		 - Verify repair Go to Step 11
11
  1. Check for proper ignition voltage output with spark tester J 26792 (ST-125). Refer to IGNITION SYSTEM for procedure.
  2. If a problem is found, repair as necessary.
Was a problem found?		 - Verify repair Go to Step 12
12
  1. Check for a loose ignition coil ground and knock sensor circuit.
  2. If a problem is found, repair as necessary.
Was a problem found?		 - Verify repair Go to Step 13
13
  1. Check the ignition coils for cracks or carbon tracking.
  2. If a problem is found, repair as necessary.
Was a problem found?		 - Verify repair Go to Step 14
14
  1. Remove the spark plugs and check for wet plugs, cracks, wear, improper gap, burned electrodes, or heavy deposits. Refer to IGNITION SYSTEM .
    NOTE: If spark plugs are gas or oil fouled, the cause of the fouling must be determined before replacing the spark plugs.
  2. If a problem is found, repair as necessary.
Was a problem found?		 - Verify repair Go to Step 15
15
  1. Check ECM grounds for the cleanliness, tightness and proper locations. Refer to the ENGINE PERFORMANCE in Electrical Diagnosis.
  2. If a problem is found, repair as necessary.
Was a problem found?		 - Verify repair Go to Step 16
16
  1. Check MAF sensor connections.
  2. If a problem is found, replace the faulty terminals as necessary. Refer to ENGINE PERFORMANCE .
Was a problem found?		 - Verify repair Go to Step 17
17
  1. Visually/physically check vacuum hoses for splits, kinks, and proper connections and routing as shown on the "Vehicle Emission Control Information" label.
  2. If a problem is found, repair as necessary.
Was a problem found?		 - Verify repair Go to Step 18
18
  1. Check the exhaust system for possible restriction:
    1. Inspect the exhaust system for damaged or collapsed pipes.
    2. Inspect the muffler for heat distress or possible internal failure.
    3. Check for a possible plugged three-way catalytic converter by checking the exhaust system back pressure. .
  2. If a problem is found, repair as necessary.
Was a problem found?		 --- Verify repair Go to Step 19
19 Check the engine mechanical component.
Was a problem found?		 - Verify repair Go to Step 20
20
  1. Review all diagnostic procedures within this table.
  2. If all procedures have been completed and no malfunctions have been found, review/inspect the following:
    1. Visual/physical inspection
    2. Tech 2 data
    3. Freeze Frame data/Failure Records buffer
    4. All electrical connections within a suspected circuit and/or system.
  3. 3.If a problem is found, repair as necessary.
Was a problem found?		 - Verify repair -
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