[b3lha]

Originally Posted by Dessertrunner

Hi Phil,
Does the ECU have a preloaded starting point for grams of fuel based on something like revs or what ever or does it just work it out. In other words if I put injectors that were 20% larger would the ECU function correctly and correct for them.
Tony

There is a parameter in the ECU that specifies the size of the injectors. It calculates that to inject x grams of fuel then it must open the injector for y milliseconds.

If you put bigger injectors, you just change the parameter and the ECU will adjust the injector open time accordingly. ie. You tell the ECU that the injectors are 20% bigger and it will open them for 20% less time to deliver the same amount of fuel.

There is also a lag time map based on battery voltage. ie. At low voltage, the injectors take longer to fully open and therefore less fuel is delivered. So you increase the pulse width slightly at low voltages to get the right amount of fuel.