Injector settings

Injector High Slope

The EEC uses the injector high slope scalar to calculate the pulse width required to deliver the desired a/f ratio.

The EEC is expecting this to be set to the actual injector flow rating at 3bar.
Injector Low Slope

The injector low slope scalar is used to account for the non-linearity of fuel injectors when operating at low pulse widths. The Injector low slope is used instead of the injector high slope when the amount of fuel to be delivered is less than the Injector breakpoint.


Injector Breakpoint

The Injector Breakpoint function is the point at which the EEC switches from the injector high slope to the injector low slope for fuel calculations.

 

The units are pound mass of fuel per injection.

 

To get my breakpoint set to 2.5ms I had to work out how much fuel (lb mass) is delivered in 2.5ms

 

First I worked out how much fuel is delivered in 1ms:

 

1000ms in a second

60 seconds in a minute..

60 minutes in a hour

42.29lb/hr injectors

 

lb mass per ms=42.29/(1000*60*60)

 

which works out to be 1.174722222e-5 AKA 0.0000117472 lbs of fuel per ms.

 

so to set it to 2.5ms I multiplied 0.0000117472 by 2.5 which gave me 0.000029368

Set the breakpoint to that and tada! A useful injector low slope!


Injector Offset Vs Battery Voltage

The EEC uses Injector Offset Vs Battery Voltage function to compensate for the injector open and close time.  The amount of time it takes the injector to open and close varies by the amount of voltage available to drive the injector.

Injectors offset examples
KAMRF

KAMRF is the long term fuel trim.  KAMRF is a multiplier that is applied to the final PW the eec calculates.


Lambse

Lambse is the A/F ratio that the EEC is commanding.  In a perfect world the Lambse is the A/F ratio that you should see on a wideband.

The value of lambse is calculated from the various fuel tables.



MAF Transfer Function

The MAF is a Mass AirFlow meter.  Meaning that it measures the volume of air passing through it by weight.  The MAF outputs a voltage signal to the EEC according to how much air is flowing by it.  The Maf Transfer Function is a function the eec uses to calculate the amount of air entering the engine.