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Home >> Buick >> 2004 >> Regal LS >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls Troubleshooting & Diagnosis 3.8L >> Troubleshooting >> Fuel Tank Leak Test >> Test Description

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. 1:  Perform this procedure in order to determine that no EVAP diagnostic DTC is present.
  2. 3:  This test locates fuel leakage in the fuel pipes.
  3. 4:  This tests for fuel leaks below the fuel tank fuel level.
  4. 5:  This test locates fuel vapors escaping above the fuel level in the fuel tank.
Fuel Tank Leak Test

Step Action Yes No
1  Did you perform the Diagnostic System Check - Engine Controls? Go to Step 2  Go to Diagnostic System Check - Engine Controls
2
CAUTION: Gasoline or gasoline vapors are highly flammable. A fire could occur if an ignition source is present. Never drain or store gasoline or diesel fuel in an open container, due to the possibility of fire or explosion. Have a dry chemical (Class B) fire extinguisher nearby.
  1. Raise the vehicle. Refer to Lifting and Jacking the Vehicle in General information.
  2. Inspect the fuel tank and the fuel pipes for damage or for external leaks.
Did you find fuel leaking from the fuel tank?		 Go to Step 6  Go to Step 3 
3 
  1. Turn ON the ignition, with the engine OFF.
  2. Command the fuel pump ON with a scan tool.
  3. Inspect for fuel leaking from the fuel pipes.
Did fuel leak from the fuel pipes?		 Go to Step 7  Go to Step 4 
4 
  1. Turn OFF the ignition.
  2. Install the J 41413-200  Evaporative Emissions System Tester (EEST) and the J 41415-40  Fuel Tank Cap Adapter.
  3. Test for a leak, referring to the J 41413-210 Operator Manual.
    4. IMPORTANT: If the floating indicator registers any flow after stabilizing, a leak is evident.
  4. Raise the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
  5. Inspect for a fuel leak while the system is under pressure.
Did fuel leak from the fuel tank?		 Go to Step 6  Go to Step 5 
5 
  1. Using the J 41413-200  and the J 41413-210 Operation Manual, introduce smoke into the evaporative emission (EVAP) system.
    2. IMPORTANT: The fuel tank may need to be partially lowered. Refer to Fuel Tank Replacement .
  2. Inspect for leaks in any of the following locations:
Did you find and correct the condition?		 Go to Step 8  Go to Diagnostic Aids
6 Replace the fuel tank. Refer to Fuel Tank Replacement .
Did you complete the replacement?		 System OK -
7 Replace the leaking fuel pipe. Refer to Fuel Hose/Pipes Replacement - Filter to Engine and Fuel Hoses/Pipes Replacement - Filter to Tank .
Did you complete the replacement?		 System OK -
8 Operate the system under the condition of the customer concern in order to verify the repair.
Did you correct the condition?		 System OK Go to Step 2 
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