Semi-Dry Sump and Direct Fuel Injection Systems
Semi-Dry Sump Injection
Used in motors where there is no D-Q pair. Injectors open simultaneously in the cylinders. Injection occurs in each downward stroke. A homogeneous mixture is achieved. The system incorporates fans and a compressor for cooling in some circumstances. It also incorporates a system for the recirculation of exhaust gases for pollution control.
MAP Sensor
Measures the absolute air pressure in the intake manifold and sends a signal to the UEC (Engine Control Unit). A higher pressure in the intake manifold indicates a greater quantity of intake air.
Service Signals
Another signal comes from the air conditioning switch, which tells the UEC that the air conditioning is on and the compressor is connected. The UEC receives the signal and increases idle revolutions. There is another signal on the power steering pump’s pressure switch, which indicates whether it is sending pressure or not. The UEC is closed when the idle speed increases.
Inertia/Impact Sensor Switch (ACT)
This is installed in all cars and has the function of disconnecting the electric fuel pump and disrupting engine function if there is a blow to the engine.
Stepper Motor
Controls the air intake, bypassing the throttle body. It supplies cold air, regulates the hot idle speed, and improves engine function in different phases.
Crankcase Heater Resistor
Its mission is to heat the gases in the crankcase to prevent them from condensing in the intake circuit.
Anti-Contamination Measures: Lambda Probes
The lambda probe is mounted after the catalyst and is responsible for checking its effectiveness. The UEC measures the values from the probe before and after the catalyst. If there is a big difference, it detects a malfunction of the catalyst and illuminates a warning light.
Exhaust Gas Recirculation System (EGR)
Sends a portion of exhaust gases to the intake to reduce the combustion temperature. The EGR valve determines the amount of exhaust gases that pass to the intake. It is controlled by the UEC as a function of engine temperature, engine speed, air pressure, and engine load. It is typically slightly open when the throttle valve is working.
Immobilizer/Starting Code
Prevents engine start without the authorized code. It can be in the key, a keyboard, or the central locking system. It immobilizes the engine through key encoding.
Direct Electronic Injection
Here, gasoline is injected directly into the combustion chamber. It is performed at a high pressure (around 100 bar) by a high-pressure pump at high engine speeds. A pressure sensor informs the UEC, and a regulator can vary the pressure. This system achieves lower fuel consumption and reduced emissions.
Stratified Lean Mode
Gasoline consumption is significantly reduced. The fuel is injected during the compression stroke, just before the spark plugs ignite. It provides very good combustion.
Homogeneous Mixture Function
This achieves maximum engine performance. Gasoline is injected during the intake stroke to create a uniform mixture. The load is controlled by the throttle.
High-Pressure Pump
Driven by the camshaft, it is fed with fuel. Its function is to supply fuel at high pressure through the injection ramp.
Pressure Sensor
Its function is to measure the high pressure in the injection ramp and report it to the UEC. If it does not send reports to the pressure regulator, there is no pressure, and the mixture is lean.
High-Pressure Regulator
Regulates the fuel pressure in the injection ramp. It consists of a coil with a voltage. If the pressure is high, it reduces it, and if the fuel pressure is low, it returns it to the low-pressure circuit.
Injector
These are reinforced and withstand higher pressure and temperature. They are mounted on the ramp, leading to the combustion chamber.