Initially, this concept was seen as a replacement for the rapidly aging carburetor injection and at its base had a fairly complex organization, which included several key components. If you have just such a car and it fell into disrepair, and along with it broke down and other parts of the car, then such a car is ready to accept for recycling here: https://towingandscrapcarremoval.ca/scrap-car-removal-ajax.
Design of the K-jetronic system
The traditional throttle valve;
Air flow meter;
Regulator that controls pressure;
Supplementary air valve.
The purpose of the throttle valve, which is controlled by a mechanical actuator connecting it to the gas pedal (gas) pedal, is to regulate the air volume flow for the formation of the working fuel mixture.
After the throttle damper is opened, a limited volume of air enters the intake manifold, shifting the discharge (pressure) disc, fixed on the lever. On the same lever, through the axle, the fuel distribution piston thrust lever is fixed, the roller resting on the piston and having on its end a screw for adjusting the quality of the mixture prepared for injection.
The distributor is used to redistribute the resulting mixture of fuel and air to the nozzles at various engine loads. The piston is pressurized from below by the pressure plate lever, and from above by the pressure created in the pilot pressure regulator, which results in a fuel/air mixture at a stoichiometric ratio (1:14.7) required for proper operation of the catalytic converter. The consequence of using such a design solution is an increased service life of the catalyst.
At the same time, the pressure regulator serves to keep the fuel pressure in the system constant. It creates the necessary conditions to maintain the pressure at the top of the ram, which creates the prerequisites for the formation of an enriched or depleted air-fuel mixture. This ensures trouble-free operation of the engine in different operating conditions, such as
at its cold start;
during warm-up in idle mode;
at peak loads.
In order to ensure problem-free engine starting in low ambient temperatures (less than 10 °C), the K-Jetronic system contains two structural elements: a starting nozzle and a valve for supplementary air.
The thermostat is mounted on the engine block and is used to control the temperature of the coolant circulating through its jacket. As is clear from the above, when the ambient air temperature is low, the relay sends a signal to the starting nozzle. When the coolant temperature reaches the programmed level, the injector stops its operation.
In order to ensure a constant supply of fuel under pressure, individual injection nozzles are used for each cylinder.
The supplementary air valve is used to supply additional air when the engine is started without the throttle valve being activated. When the engine is cold, the valve is fully open, as soon as the engine starts to warm up, the valve, under the influence of the bimetallic plate connected to the valve diaphragm, gradually closes until the air supply is completely cut off.
The power plant manufacturer uses special adjustment screws as idle speed adjustment tools:
The first of these is used to set the idle speed of the crankshaft;
The second is used to adjust the quality characteristics of the mixture, affecting the concentration of carbon monoxide in the exhaust.
Principle of operation of the K-jetronic
Pressing the accelerator pedal activates the throttle valve, which opens. The air flowing through the choke acts on the pressure plate of the air flow meter. This causes the disc to move, thereby causing the metering plunger to move.
Under constant pressure, which is guaranteed by the presence of a pressure regulator in the system, the fuel is fed to the metering plunger. Through the kinematic connection between the metering plunger and the air flow meter disk, the pressure of the fuel mixture supplied to the injectors is adjusted.
If the diameter of the injector injection channels is constant, the amount of fuel supplied depends on the pressure developed at the injector inlet. Fuel metering is realized through the synchronized operation of the air flow meter and fuel metering device and is directly related to the operating mode of the power unit.
Increase in engine rpm at startup and when idling is ensured by feeding an additional portion of air to the intake manifold through a special valve (additional air supply), and simultaneously with the air an additional portion of fuel is fed. The starter nozzle is responsible for the fuel supply.