EVAP System, Testing
-- Plug or clamp LDP inlet (filter side) using Hose Clamps Up to 25 mm Dia. :VAS3094 or equivalent.
-- Attach fuel cap adapter to filler neck (-arrow-) and test hose to adapter.
-- Set control valve -2- from "Hold" to "Test".
-- Increase the current pressure until it reaches 10 in. (25 mbar) H2 O.
-- Monitor the pressure gauge -3- and the flow meter -4-. Allow the flow rate to decrease. If pressure builds to 10 in. (25 mbar) H2 O, 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 to 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. (20 mbar) H2 O.
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.
Clamp only soft rubber lines when isolating a leak. To avoid risk of damage, never clamp hard plastic lines!
Any flow shown on flow meter indicates a leak.
If flow meter on tester registers flow near or above preset pressure:
-- 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 .