EVAP System, Testing
-- Remove The Filter Hose From The Fuel Tank Leak Detection Control Module.
Clamp Only Soft Rubber Lines When Isolating A Leak. To Avoid Risk Of Damage, Never Clamp Hard Plastic Lines!
-- Plug or clamp the fuel tank leak detection control module filter port using Hose Clamps Up to 25 mm Dia.:VAS3094 or equivalent.
Vehicles Equipped With The Fuel Tank Leak Detection Control Module May Require One Of Two Different Test Adapters That May Vary Depending On The Model.
-- Attach Evaporative Emissions Tester - Adapter 57:KLI9210/57 or T adapter between the EVAP system and the EVAP Canister Purge Regulator Valve 1 -N80-.
No Special Tool T Adapter Is Available At This Time. The T Adapter May Have To Be Fabricated If It Is Required For Testing.
-- Attach the test hose from the Evaporative Emissions Tester:KLI9210 to the adapter.
-- Set control valve -2- from "Hold" to "Test".
Calibrate Evaporative Emissions Tester:KLI9210 To 10 in. Of Water Prior To Connecting The To The Vehicle.
-- Increase the current pressure until it reaches 10 in. H2O (25 mbar).
-- Monitor the pressure gauge -3- and the flow meter -4-. Allow the flow rate to decrease. If pressure builds to 10 in. H2O (25 mbar), the fuel system is full.
Depending On The Level Of Fuel In The Tank, It May Take Up To Three Minutes To Notice A Visible Decrease In Flow Rate.
- If any flow is shown on meter, a leak is present in the system. Locate the leak.
- If no flow is shown on the meter, proceed with the following steps.
-- After the pressure has stabilized, set control valve -2- to "Hold".
-- After five minutes, the pressure must not drop below 8 in. H2O (20 mbar).
If pressure drops below 8 in. of water in five minutes then find leak with the smoke tester, soapy water and/or isolating components by clamping them off individually.
If Fuel System Pressurization Does Not Stabilize:
-- Verify all fuel system outlets have been sealed before continuing.
Any Flow Shown On Flow Meter Indicates A Leak.
If flow meter on tester registers flow near or above preset pressure:
Clamp Only Soft Rubber Lines When Isolating A Leak. To Avoid Risk Of Damage, Never Clamp Hard Plastic Lines!
-- Clamp off hose -arrow- leading from EVAP Canister Purge Regulator Valve 1 -N80- to intake manifold.
If No Flow Is Present And The Pressure Drop Is Above 8 in. Of Water After Five Minutes:
-- Replace EVAP Canister Purge Regulator Valve 1 -N80- and repeat test before continuing.
If Meter Indicates No Flow After Test:
-- Perform a quality check and return vehicle to customer.
If Flow Continues, Proceed As Follows:
-- Refer to METHOD 1: LOCATE LEAK WITH SMOKE GENERATOR .
-- Refer to METHOD 2: LOCATE LEAK WITH ULTRASONIC TESTER .