Volkswagen Workshop Service and Repair Manuals

Note:

Removing return spring and throttle lever

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Special tools, testers and auxiliary items

• ◆ Thrust plate VW 401

• ◆ Thrust plate VW 454
• ◆ Drift 10-206

Work sequence

• ‒ → Mark position of fuel delivery adjusting screw relative to pump cover, e.g. slot of screw relative to pump cover -arrows-.
• ‒ Loosen locking nut against the locking sleeve and unscrew fuel delivery adjusting screw from the pump cover.

Note:

The smallest mal-adjustment of the fuel delivery adjusting screw can cause sooting or loss of engine power. Therefore it is important that the adjusting screw is re-installed in the same position. On no account may the fuel delivery adjusting screw be screwed in past the original position.

• ‒ Remove fuel return pipe.
• ‒ Wrap a cloth around the fuel pump to absorb leaking fuel.

• ‒ Remove cover securing bolts (Qty. 4).
• ‒ Separate the idling speed throttle lever from the idling speed adjusting rod by removing the circlip.
• ‒ → Tip pump cover slightly to one side, and detach idling speed spring -arrow- (e.g. using locally manufactured hook). Do not over tension spring.

• ‒ → Lift pump cover slightly, press throttle lever shaft -arrow- towards the inside of the cover (e.g. with a screwdriver handle) whilst taking the cover off.

• ‒ → Remove pump cover and press bush out as illustrated.
• ‒ Clean pump cover

Note:

Various bushes are available depending on type of pump. Select correct bush by comparing with old bush.

• ‒ → Coat new bush outer diameter with D6 and press into the cover up to the collar as illustrated.
• ‒ Carefully remove surplus D6.

• ‒ → Install new throttle shaft O-ring -2-.
• ‒ Ensure that the thrust washer -3- is in place.
• ‒ Fit new pump gasket. (Small protrusions on gasket outer edge prevent the gasket falling out when the cover is fitted).
• ‒ Moisten throttle lever shaft and O-ring with Diesel land press into bush, then fit pump cover.
• ‒ Attach idling speed spring.
• ‒ Secure pump cover.
• ‒ Install fuel delivery adjusting screw with new O-ring, as marked.
• ‒ Install return spring and throttle lever
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• ‒ Run engine until warm and check idling speed and engine governed speed.
• ‒ Check exhaust opacity with combustion tester V.A.G 1500

=> Fault finding programme Diesel engine No. 2 "excessive black exhaust smoke".