Engine management system - EDC (Turbocharger): Description and operation

Turbocharger

The turbocharger unit is located at the left hand end of the exhaust manifold and comprises a die cast housing and a pneumatic actuator.

The housing contains a turbine on a shaft which is driven by exhaust gases. At one end of the turbine shaft is a compressor, mounted on the intake side of the turbocharger. The housing has two main ports. One port receives exhaust gases from the manifold and the other receives clean air from the air filter. Two smaller ports provide an air pressure feed of clean air to the wastegate actuator and the MAP sensor.

The MAP sensor, which is located on the bulkhead, is used to detect intake air pressure changes which enable the ECM to calculate the volume of oxygen in the intake air.

Two oil lines provide lubrication for the turbocharger. A small diameter pipe supplies oil under pressure from the engine oil pump. A larger pipe provides the oil return from the turbocharger to the cylinder block.

Intercooler

The intercooler is positioned at the front of the vehicle to the left of the radiator and is mounted in rubber bushes located on the front body cross member and the bonnet locking platform. The intercooler is an aluminium cross flow construction with plastic mouldings at top and bottom. The plastic mouldings each incorporate a hose connection port.

The intercooler receives a compressed air/exhaust gas mixture from the turbocharger via a hose to the bottom connection port. The top connection port, supplies cooled, compressed air/exhaust gas mixture from the intercooler to the engine inlet manifold via a hose. The intercooler reduces the temperature of the compressed air from the turbocharger which increases the air density.