Definition: Momentary lack of response as the accelerator is pushed down. Can occur at any vehicle speed. Usually most pronounced when first trying to make the vehicle move, as from a stop sign. May cause the engine to stall if severe enough.

Was the Powertrain On-Board Diagnostic(OBD) System Check performed?

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Go to Step 2

Go to the Powertrain On Board Diagnostic (OBD) System Check

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?

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Go to Step 21

Go to Step 3

Was visual/physical check performed?

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Go to Step 4

Go to Visual/Physical Checks

1. Check Heated Oxygen Sensors (HO2S). The Heated Oxygen Sensors (HO2S) should respond quickly to different throttle position. If they don't, check the HO2S for silicon or other contaminants from fuel or use of improper RTV sealant. The sensors may have a white powdery coating. Silicon contamination causes in a high but false HO2S signal voltage (rich exhaust indication). The PCM will then reduce the amount of fuel delivered to the engine , causing a severe driveability problem. For more information, refer to Information Sensors .
2. If a problem is found, repair as necessary.

Was a repair required?

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Go to Step 5

1. Check fuel pressure. Refer to Fuel System Pressure Test .
2. If a problem is found, repair as necessary.

Was a problem found?

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Go to Step 21

Go to Step 6

Observe TP angle display on the scan tool while slowly increasing throttle pedal.

Does the TP angle display steadily increase from 0% at closed throttle to 100% at WOT?

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Go to Step 20

Monitor Long Term Fuel Trim on the scan tool.

Is Long Term Fuel Trim significantly in the negative range (Rich condition)?

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Go to Step 9

1. Check items that can cause the engine to run rich. Refer to DTC P0172 Fuel Trim System Rich .
2. If a problem is found, repair as necessary.

Was a problem found?

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Go to Step 21

Go to Step 10

1. Check items that can cause the engine to run lean. Refer to DTC P0171 Fuel Trim System Lean .
2. If a problem is found, repair as necessary.

Was a problem found?

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Go to Step 21

Go to Step 10

1. Check for proper ignition coil output voltage with spark tester J 26792 :

-	Clip the spark tester to engine ground.

-	Connect one end of a spark plug wire to the spark tester; connect the other end of the spark plug wire to the coil being tested.

-	Connect one end of another spark plug wire to the other coil tower; connect the other end of the spark plug wire to ground.

-	Crank the engine while observing the spark tester; a crisp blue spark should be observed.

-	Repeat the above steps for each coil.

2. If adequate spark is not present at all coils, repair as necessary.

Was a problem found?

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Go to Step 21

Go to Step 11

1. Check for loose ignition control module ground.
2. If a problem is found, repair as necessary.

Was a problem found?

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Go to Step 21

Go to Step 12

1. Visually/Physically inspect secondary ignition wires. Check for the following conditions:

•	Check all Ignition wire resistances; should be less than the specified value.

•	Ignition wires for cross firing.

•	Ignition wires arcing to ground.

•	Ignition wires for improper routing.

Important: Spraying the secondary ignition wires with a light mist of water may help locate an intermittent problem. Ignition components will arc to ground when a secondary component is faulty.

1. If a problem is found, repair as necessary.

Was a problem found?

30,000 ohms (30K ohms)

Go to Step 21

Go to Step 13

1. Check ignition coils for cracks or carbon tracking.
2. If a problem is found, repair as necessary.

Was a problem found?

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Go to Step 21

Go to Step 14

1. Check ignition coil secondary resistance.
2. Replace any coil(s) which are not within the specified values. Refer to Ignition Control Module Replacement .

Did any coil(s) require replacement?

5000-8000 ohms (5K-8K ohms)

Go to Step 21

Go to Step 15

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

Notice: Determine the cause of the oil or gas fouled spark plugs in order to avoid damage to the new spark plugs.

1. If a problem is found, repair as necessary.

Was a problem found?

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Go to Step 21

Go to Step 16

1. Check PCM grounds for being clean, tight and in the proper locations. Refer to Engine Controls Schematics
2. If a problem is found, repair as necessary.

Was a problem found?

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Go to Step 21

Go to Step 17

1. Check MAF sensor connections.
2. If a problem is found, replace faulty terminals as necessary. Refer to Repair Procedures in Electrical Diagnosis.

Was a problem found?

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Go to Step 21

Go to Step 18

1. Visually/physically check vacuum hoses for splits, kinks, and proper connections and routing. Refer to Emission Hose Routing Diagram .
2. If a problem is found, repair as necessary.

Was a problem found?

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Go to Step 21

Go to Step 19

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:

•	Visual/physical inspection.

•	Scan Tool data.

•	Freeze Frame data/Failure Records Data.

•	All electrical connections within a suspected circuit and/or system.

3. If a problem is found, repair as necessary.

Was a problem found?

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Go to Step 21

Refer to Technical Service Bulletins

Replace the TP sensor.

Is Action complete?

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Go to Step 21

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Operate the vehicle to duplicate conditions present when the original symptom was noted.

Is symptom still present?

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Go to Step 3

System OK