bk simmerath

Function

This petrol-injection signal is registered with the Bosch FSA 600. It is intended rather for learning than for error analysis. It shows the form and the distribution of the injection signals in relation to the crankshaft position.

How it works

First of all, you might want to take a view of the injection signals on top. The opening tension of 12 V is striking. How many injectors are opening up right now, cannot be read. But the opening period of 2 - 3 milliseconds is readable on the lower scale. A better accuracy would be possible by zooming into the X area. Typically for direct current magnetic valves (injectors) are the high induction tension in opposite direction while switching off.

Below you can see cogs at the flywheel (rear engine) or at the V-belt pulley (engine in front) flitting by the inductive pickup. With some patience it would be possible to count them. These are not, by the way, the cogs of the starter rim, because one cog is absent. This is recognizable by the gap and serves as a reference mark. Because of the gap the induction alternating voltage also deflects a little more to both sides.

It is interesting to look at both diagrammes simultaneously. You know that a total of approx. 2.5 crankshaft rotations have been registered. You could control the indicated revs and think about which fuel amount (completely or half) was injected by the valve shown...