The principle of operation of the injection system
During start-up During
start-up, ie while the starter of the Transporter T4 , the injection system is controlled directly by a microprocessor module, whose task is to determine the injection time in relation to the coolant temperature.
Information about the temperature of the coolant is supplied to the microprocessor module by a temperature sensor placed next to the fitting that drains the coolant from the head of the block.
At low temperature
An incoming air temperature sensor is installed at the top of the movable damper of the flowmeter.
Its task is to provide the microprocessor module with the information necessary to determine the injection time, depending on the air temperature, in order to maintain the ratio of air mass to fuel at the same level. At full load
To ensure optimal engine operation under different operating conditions, different fuel-air mixtures are required.
During operation at full load, it is necessary to supply more fuel conditions for the development of the greatest power of the power unit. The damper position sensor transmits information about the damper position to the microprocessor module.
This is due to two contacts, one of which is responsible for full load, the other for idling. Having received a full load signal, the microprocessor module regulates the amount of fuel supplied, enriching the mixture by approximately 10% in the case when the damper is open more than 75% of the full opening value.
Fuel pressure regulator
The fuel pressure regulator is identical to that described for the Digifant system.
Additional air supply valve
The auxiliary air supply valve is completely similar to that described for the Digifant system.
Speed and crankshaft position sensors
Speed sensor (A)
The sensor is mounted above the flywheel ring gear (see Fig. 302). It transmits information about the crankshaft speed to the microprocessor module in the form of electrical impulses caused by the movement of the teeth of the ring gear.
Rice.
302 Speed sensors / crankshaft position A - speed sensor, B - TDC sensor, c - mark on the flywheel
Crankshaft position sensor (B)
The crankshaft position sensor (see Fig. 302) is also located above the ring gear and transmits pulses to the microprocessor control module corresponding to the presence of the piston at top dead center (TDC).
Engine temperature sensor
The engine temperature sensor is identical to that described for the Digifant .
Throttle position sensor
The damper position sensor is completely similar to that described for the Digifant system.