Fuel Injection Adjustment for VW 1Z Engine

Hello everyone,

Yesterday, I successfully cleaned the MSW (Mass Storage Unit) of my ESP (Electronic Stability Program). The stuttering is finally gone, and the car drives like a "German-made" car again. Thank you to the person who created the instructions for this process.

Okay, I have a question regarding the injection quantities. I'm working with DIAS, an older diagnostic program. There, I can view the measurement data blocks, and in the manual for cleaning the ESP (Electronic Stability Program), it states that if the displayed value is high, the injected quantity is small. Why is that? They also specify the unit as mg/stroke, so why is there this relationship? I don't quite understand the connection... can someone perhaps explain it to me?

If I increase the actual injection amount (by adjusting the MSW) slightly now, is that harmful to my engine, or can I drive with it without any problems? I would like to gradually approach the "visible" soot limit. Currently, I have 5 mg per injection stroke at idle with a warm engine.

Thank you for the information.

stummel78 wrote:

that when the displayed value is high, the injected amount is small...why is that? Isn't the unit also specified as mg/dose? I don't really understand the connection...can someone perhaps explain it to me?

Hi,

At idle, the engine speed is regulated, and typically, a warm TDI without high electrical loads (let's say) produces approximately 5 mg per stroke.

If the MSW (measuring system) indicates a low value ("mager"), it must be adjusted to allow for the injection of 5 mg, such that the reading corresponds to a higher amount, say 7 mg.
And these 7 mg will also be displayed in the diagnosis because the infusion pump believes it is administering 7 mg!

If the engine produces a maximum of 40 mg of something at full throttle, that's only 33 mg more than it produces at idle.
If we theoretically (in practice, this is not possible, but for the sake of explaining the principle, let's assume) push the MSW to its extreme limit and set it so low that it displays 40 mg even at idle, then what happens when you give it full throttle?
Absolutely nothing more, because the engine won't come out of idle, because the EDC is already giving full throttle for what it believes to be the actual idle amount believes!

If the MSW (motor software) is set to a "rich" setting, for example, displaying 3 mg on the gauge at idle, then there's a difference of 37 mg between idle and full throttle, and the engine actually produces more power than with a normal or leaner MSW setting.

And all of this, despite the fact that, in reality, the aforementioned 5 mg are always injected when the system is idle!

(The 5 mg idle setting is not officially specified and depends on many factors.)
However, whether 4.7 mg or 5.6 mg are injected instead of the initially specified 5 mg as the actual idle amount is irrelevant to the principle described.