MoTeC Global Forum

The base fuel map contains a percentage of the IJPU.
How are the compensations applied to the base fuel pulse with ?
Are all compensations added and substracted to the percentage mentioned in the Base fuel map.
Or are they applied to the already calculated fuel pulse with and if this is the case how is the ranking of corrections applied.
Also for the low and high injectors. If we trim one secondary injector +5 %. How does this effect the fuel pulse with.
With for example an IJPU of 20 ms and 45 % in the base fuel map and a hi/low ratio of 20 %.

The "Fuel Base Pulse Width" is the percentage of IJPU determined by the number in the fuel table.
Any trims are added together to form the "Fuel Effictive Pulse Width" as a total trim.
The injector dead time is added to "Fuel Effective Pulse Width" to give the "Fuel Actual Pulse Width"
An individual trim is applied to the "Fuel Base Pulse Width" for the particular injector.

So for your example:
45% of 20 = 9ms
20% Hi Lo Ratio = 1.8ms
5% Individual trim = 1.89 ms

If , for example you also had a +10% Engine Temp trim and a - 2% Air Temp trim you would have total trims of 8%:

1.89ms + 8% trim + 2.04ms. Injector dead time is then added to this.

Is it possible you have to devide the Base pulse width by the number of cylinders and then apply the total of trims to get the effective PW ?
I logged all trims and base PW, effective PW prim & sec, actual PW prim & sec and did the calculation. It's not correct except when I divide the Base PW with the trims by the number of cylinders and then I get the effective PW prim & sec.

You should not have to divide the Fuel Base Pulse Width with the number of cylinders. Fuel Effictive Pulse Width should be the Fuel Base Pulse Width with trims added. When using secondary injection the Fuel Base Pulse Width with trims added should be equal to Fuel Effective Pulse Width Primary + Fuel Effective Pulse Width Secondary.

This is not the case.
Below you can see the logging of the comps, base - and Effective Pulse Width.
There are some comps not logged but I checked all of them and at the above point they are 0.
The indiv comps of the secondaries I added in the next drawing.

I don't know why you are seeing this in your logging, are you able to send me your configuration file?

Hello Ross,

In the meantime I know why. The secondary injection ratio is at 4.
So the base pw which is working on the secondaries has to be devided by 4.

thanks anyway.