Due to the increased legislation concerning exhaust gas, the Lambda control had to be also integrated into the K-Jetronic. This was also the opportunity to immediately eliminate a long standing problem, the
difficulties occuring during hot starting. However, the equipment, with its complicated hydraulic and electronic regulation was no longer competitive.
How it works
The K-Jetronic was fitted with a control device, a potentiometer in the air sensor plate and an hydro-electric pressure plate. The control device reacts to the
signals of the Lambda sensor
and the potentiometer (strain signal). Through the pressure plate, it can change the pressure to the lower chambers. The once low pressure difference of 0.1 bar can now be increased to the tenfold. In addition,
contacts on the throttle valve allow overrun cut-off and full-load enrichment.
The hot starting problems have have been following some manufacturers for more than 10 years. They develop from the strong heating up of the fuel in the fuel-line and the resultant vapour bubbles. The problem was
finally solved by distinctly increasing the system pressure, the larger volume of the fuel accumulator and the systematic sealing of all fuel flow-backs by the piston of the pressure control (see figure in K-Jetronic). When the engine is shut-down. Thus, a remaining pressure of more than 3 bar can be kept up for one month.
The second figure above, shows the position of the parts in the engine compartment. On the bottom right, the casing for the fuel mixture control and the air sensor plate, which is raised in this case, by the intake air
coming from the air filter below it. The air is conducted further upwards to the throttle valve/s, and the, in this case, chrome plated inlet air distributor. Typical for the KE-Jetronic, is the cluster of fuel pipes from the
mixture control unit on the bottom right, to the individual injectors in the cylinder head.
Finally, the KE-Jetronic was also built with integrated ignition and known as Motronic.
Ignition signal (terminal 1), air sensor plate potentiometer, Lambda sensor, temperature sensor (coolant), throttle
Fuel pump, stroke valve (active carbon filter), hydro-electric pressure control. 10/09