The component shown in the above picture, has become quite a little jewel. This was what regulated the fuel supply in the Peugeot 504. My assistant at the university drove a car like this and he seemed to be pretty satisfied with it. And, because in my opinion, he knew a great deal about motor car technology, perhaps we should deal with this little gem and some of it's contemporaries of that time.

This component was made by the Kugelfischer Company, who were world famous for their ball-bearings and seemed to be predestined for the the particular precision necessary for a petrol injection system. This you can see by the position of the four connections in Diesel in-line fuel injection pumps, only here, they have an additional lubrication of the piston through the engine oil.

In the Diesel engine, the intake stroke is interrupted when the control-edge reaches the inlet port. In this pump, the intake stroke is limited because the piston does not return to it's lowest point. Thus, if only a little fuel is used, the stroke begins at about half way, or in fact, even less.

The Diesel engine has it easier. If more is injected, it simply runs faster, because enough excess air always exists. If even more is injected, then it just begins to soot-up. Indeed, a petrol engine can also soot up but as a rule, not for very long because then the spark plugs stop functioning.

This means, as far as the injection system is concerned, the fuel travel is shorter because of the much lower pressures needed in the intake-manifold fuel injection (e.g., just under 30 bar), at the same time, an unbelievable amount out regulation technology is necessary. To put it simply, even in the time before the Lambda regulation, the gas-pedal position, the airflow rate, the RPM and optionally, even the density of the air, e.g., up in the mountains, also had an influence.

Now, try to imagine a plate with four drill-holes and held by a single bearing, which influences the piston's return travel after the injection point and thus, the new filling capacity through raising and lowering the side opposite to the bearing. All the pistons can return to their initial positions, as long as the plate permits them to do so. Here, there is a chamber-cam, which lifts and lowers this plate.

It is moved through the gas-pedal together with the throttle flap, and that, in an axial direction. Thereby, the plate is by no means always lowered proportionally to the gas-pedal deflection. In addition, the cam rotates, depending on the RPM, influencing an eddy current transducer, similar to the earlier operation of the speedometer.

The regulating pivot-plate is not only supported by the chamber cam. In addition, one of the shafts can also be lifted by an eccentric cam. The enriching effect is needed, e.g., during or after the cold starting, which is caused by a certain opening temperature through a thermostat which dips into the coolant. The height correction is operated by an opening for the secondary air. 12/13