OK, How do we make a quick smoke-free diesel tune solution?
Here is a simple trick for tuning the diesel fuel limit map if you want it smoke free, using a wide band lambda sensor.
First record a long data log, 10-30 minutes of driving at variable load, ensuring the lambda sensor is connected and recording.
Next create a user defined variable in the log viewer where you calculate the ratio between the indicated lambda and a theoretical smoke free lambda which in this case I define as lambda 1.3 as a common smoke-free number for most diesels.
Add a histogram tab, using engine speed as x axis and map as y axis, and the newly created variable as the Z axis, set a reasonably large minimum hit count to only show data for fields where a lot of data is available.
The histogram will now show what the fuel limit needs to be to attain a smoke free 1.3 lambda at any given boost pressure and speed combination. You can then extrapolate from there to the fields that did not get much hits in the log. Also pay attention to your boost targets, if the fuel limit shown at any given pressure is a fuel quantity where less than this pressure is commanded in the boost target map then you need more boost for optimal performance.
