Golf L4-1588cc 1.6L DSL SOHC Turbo (1985)
Turbocharger: Description and Operation
The turbocharger is an exhaust driven device which compresses the air/fuel mixture to increase engine power on a demand basis.
A turbine in the exhaust gas flow is connected through a shaft to the impeller (compressor). During normal, steady operation, the turbine does not
rotate with sufficient speed to boost pressure to compress the air/fuel mixture. As engine speed increases, the mixture is compressed, allowing the denser
mixture to enter the combustion chambers and develop more engine power during the combustion cycle.
The intake manifold boost pressure is controlled by a wastegate valve which is used to bypass a portion of the exhaust gases around the turbine at a
predetermined point in the engine cycle, limiting the boost pressure.
To prevent loss of engine power due to lack of fuel, there is a manifold pressure compensator mounted on the injection pump. The compensator
incorporates a push rod and diaphragm assembly connected to the injection pump distributor plunger. During turbo boost the amount of fuel delivered to
the injectors is increased. The turbo boost enrichment is preset at the factory, and no adjustment is required. If the unit is faulty, it must be replaced. The
only concern is to see that the housing vent is open when installing a new pump or compensator.
