Volkswagen Workshop Service and Repair Manuals > Golf Mk5 > Power unit | 4-cylinder injection engine (1.8 and 2.0 l engine, chain drive) | Mixture preparation system, electronic inj.,Gas | Checking components

Checking intake manifold change-over

Perform check only if there is a loss of torque. This means when there is a lack of elasticity or a lack of pulling power.

Special tools and workshop equipment required

t	Hand vacuum pump -VAS 6213-

Test prerequisite

t	The variable intake manifold valve -N316- was checked with a vehicle diagnosis tester.

If the intake manifold flap valve -N316- is OK, perform the following tests:

–	Pull engine cover off carefully.

–	Start engine and run at idling speed.

–	Ask a second person to abruptly increase engine speed (throttle burst). Observe vacuum unit for intake manifold change-over.

l	The actuator must move -arrow-

If the changeover does not function as described:

–	Check vacuum system for leaks.

–	Check mechanical change-over components for ease of movement. To do this, operate rods by hand.

–	Check that vacuum lines are connected correctly.

–	Check vacuum hoses for porosity.

–	Remove vacuum hose -1- leading to actuator for intake manifold valve flap -N316- from intake manifold flap valve -N316--2-.

–	Move slide ring -1- on hand vacuum pump -VAS 6213- to position -A- for "vacuum".

–	Connect hand vacuum pump -VAS 6213- to actuator for intake manifold flap valve -N316-.

–	Operate hand vacuum pump -VAS 6213- repeatedly.

The vacuum actuator must move -arrows-.

–	If the vacuum actuator does not move, replace it.

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