Evaporative Emission (EVAP) Canister Purge Regulator Valve N80 System, Checking For Leaks

Evaporative Emission (EVAP) Canister Purge Regulator Valve N80 System, Checking For Leaks

Special tools, testers and auxiliary items required
- Fuel system tester (smoke tester) KLI 9210
- Hose adapter KLI 9210/55-1
- Vehicle Diagnosis, Testing and Info. System VAS 5051B, VAS 5052 or VAS 5053







- Hose clamps up to 25 mm dia. 3094

Test conditions:
- A leak was detected by Leak Detection Pump (LDP) V144.
- Guided Fault Finding was performed with Vehicle Diagnosis, Testing and Info. System

Evaporative Emissions Tester KLI 9210 preparation:

NOTE: Depending on the version, the appearance of the Evaporative Emissions Tester KLI 9210 may vary.

- Check on Evaporative Emissions Tester KLI 9210 whether there is enough fluid in the smoke generator.







- Set valve - D - to "Hold".
- Open nitrogen bottle - H -.
- Connect measuring hose - G - on self-test connection - B -.
- Set valve - D - to "Test".
- Using pressure reducer - J -, adjust pressure to 10 in. H2O (25 mbar).
- Set valve - D - to "Hold".
- The pressure must now be maintained min. 2 minutes. If pressure is not maintained, check tester.

Fuel system, checking for leaks:







- Connect Adapter Hose KLI 9210/55-1 to ventilation line - A - between the purge valve and canister in engine compartment as shown.







- Connect measuring hose - G - on Evaporative Emissions Tester KLI 9210 to Adapter Hose KLI 9210/55-1.
- Set valve - D - to "Hold".







- Connect Vehicle diagnosis, testing and information system VAS 5051B, VAS 5052 or VAS 5053 to vehicle as illustrated.
- Start engine and run at idle speed.
- Select Guided Functions operating mode on Vehicle diagnosis, testing and information system VAS 5051B, VAS 5052 or VAS 5053.
- Select "Check tank ventilation system for leaks" guided function. Activate test.
- While test runs, observe pressure gauge on Evaporative Emissions Tester KLI 9210.
- Leak Detection Pump (LDP) V144 must pump fuel system pressure up to at least 7 in. H2O (17 mbar).

The minimum pressure is not reached, but pressure reached does not decrease:
- Switch ignition off and perform pressure retention test by monitoring the pressure displayed on the KLI 9210 Pressure gauge (C). If no decrease in pressure is observed: Check Leak Detection Pump (LDP) V144 vacuum supply.

The minimum pressure is not reached and pressure reached decreases immediately:







- Clamp off hose to Evaporative Emission (EVAP) Canister Purge Regulator Valve N80 with hose clamp.
- Repeat test. If minimum pressure is not reached: Replace Evaporative Emission (EVAP) Canister Purge Solenoid Valve N80.

The minimum pressure is not reached again and pressure reached decreases immediately:
- Leak in fuel system, perform "leak test in fuel system".

If minimum pressure is reached, switch ignition off
The valve in Leak Detection Pump (LDP) V144 is now closed and pressure is maintained.
- Observe pressure gauge:

If pressure does not decrease, perform a pressure retention test to locate any possible pinhole leaks.







If pressure decreased, clamp off hose to Evaporative Emission (EVAP) Canister Purge Regulator Valve N80 with a hose clamp.
- If pressure now no longer falls, replace Evaporative Emission (EVAP) Canister Purge Regulator Valve N80.

If pressure still decreases, perform "leak test in fuel system".

Pressure retention test







- Set valve - D - to "Test". Increase present pressure up to 10 in. H2O (25 mbar).
- Observe pressure gauge - C - and flow meter - E -. If the flow quantity decreases and pressure increases to 10 in. H2O (25 mbar), fuel system is filled.

NOTE: Depending on the level in the fuel tank, this procedure may take up to 3 minutes.

- After pressure has stabilized, set valve - D - to "Hold".
- After 5 minutes pressure must not drop below 8 in. H2O (20 mbar).

If pressure is not maintained for 5 minutes, the leak should be localized as follows:







- First check Evaporative Emission (EVAP) Canister Purge Regulator Valve N80 for leaks. Clamp off hose to Evaporative Emission (EVAP) Canister Purge Regulator Valve N80 with hose clamp.







- Repeat pressure test by resetting valve - D - to "Test".
- Observe pressure gauge and flow meter. If flow quantity decreases and pressure increases to 10 in. H2O (25 mbar), fuel system is filled.
- After pressure has stabilized, set valve - D - to "Hold".
- If pressure now no longer falls, replace Evaporative Emission (EVAP) Canister Purge Regulator Valve N80.

If pressure still decreases, perform "leak test in fuel system".

After completing work, perform "Check tank ventilation system for leaks" guided function using.

Leak test in fuel system

Test conditions:

- Procedure for "Checking fuel system for leaks" performed.







- Evaporative Emissions Tester KLI 9210 with Adapter Hose KLI 9210/55-1 connected to vehicle
- Connect Evaporative Emissions Tester KLI 9210 to vehicle battery.
- Remove right rear wheel housing liner.







- Clamp off hose between Leak Detection Pump (LDP) V144 and air filter - arrow -.







- Set valve - D - to "Test".
- Observe pressure gauge - C - and flow meter - E -. If flow quantity decreases and pressure increases to 10 in. H2O (25 mbar), fuel system is filled.
- After pressure has stabilized, set valve - D - to "Hold".
- After 5 minutes the pressure must not drop below 8 in. H2O (20 mbar).
- If pressure no longer decreases, replace Leak Detection Pump (LDP) V144.

If pressure is not maintained for a minimum of 5 minutes or if no pressure is built up, localize leak as follows:
- Fill fuel system with smoke by setting valve - D - to "Test".
- While fuel system is being filled, press smoke generator button - 1 - for approx. one minute.

The fuel system is now under pressure and filled with smoke.
- Check all fuel system lines and hoses for escaping smoke. Also check fuel tank sealing cap.

NOTE:
- Illuminate components and hoses with a strong flood light, the smoke will be more visible.
- To check for leaks at accessible locations, also use ultrasonic measuring device or commercially available leak detection spray.
- Depending on how long fault finding lasts, smoke generator button may have to be pressed again. This ensures there is enough smoke present in the fuel system.
- To check fuel pump and fuel filter flange, the assembly openings in the vehicle interior must be opened.

- Replace leaking hoses or components.

After completing the work, perform "Check tank ventilation system for leaks" Guided Function using.