Injectors
This tab contains settings for injector size and fuel trim.
Changing the injector size will automatically compensate the fuel tables for the rating of the injector (but not for the specific characteristics of the injector). Also the cranking fuel is compensated based on the injector size.
Fuel Trim
The overall fuel trim is an additional compensation applied evenly to the main fuel tables. The cranking fuel trim is applied when starting the engine.
Note that the injector size will automatically reduce the overall fuel and cranking fuel even if the trims are set to zero.
Cylinder Fuel Trim
By changing the cylinder fuel trim it is possible to add or remove fuel for individual cylinders. Note that the injector duration as datalogged is the duration for injector #1. Changing the fuel trim for cylinder #1 will result in the datalogging showing the duration for cylinder #1, not the rest of the cylinders. Warning: Do not set the cylinder fuel trim from reading the spark plugs. The only reliable way to set the fuelling for individual cylinders is using EGTs.
Voltage Compensation
Advanced Feature: If you are unsure what this feature does do not change this table.
Injectors have a minimum pulse width before any fuel is injected, known as the injector 'dead time' or 'lag'. This varies by voltage and may be adjusted for different injector characteristics. The dead time vs voltage is usually available from the injector manufacturer.
Cranking Fuel
Advanced Feature: If you are unsure what this feature does do not change this table.
This determines the injector pulse while cranking based on coolant temperature. Note that the cranking fuel is automatically adjusted when the injector size is changed, so normally no adjustment to the cranking base fuel table is necessary.