Plug-In ECU Installation Manual 17
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a. If using Traditional Fuel Equation Mode then locate the 'Master Fuel' setting in the ECU Settings Menu
under: Fuel > Fuel Setup > Fuel Main. This will need to be adjusted during or just after start-up.
b. If using one of the Modelled Fuel Equation Modes then navigate to Fuel > Fuel Setup > Fuel main and
enter the correct engine capacity, correct base fuel pressure, and correct fuel properties. Navigate to
>Fuel>Fuel Setup>Injector Setup, enter correct injector flow rate and rated pressure.
6. Crank the engine until it starts. Some throttle may be required for first time start-up due to imperfect
tuning.
a. If using Traditional Fuel Equation Mode the Master Fuel setting can be used to enrich/lean the engine
(increase to enrich).
b. If using one of the Modelled Fuel Equation Modes the Injector Flow Rate can be decreased to add
more fuel, this will need to be changed back to the correct value later but works well for first start
purposes.
7. If the engine fails to start after several attempts, do not crank it endlessly. Stop and determine the
problem before continuing.
8. Check the Trigger Error Counter (found under the Triggers runtime values tab). If this value increases
during cranking/running then there is a trigger setup fault. It is not unusual for this number to count one or
two on the first engine revolution.
9. Once the engine starts:
a. If using Traditional Fuel Equation Mode adjust the Master Fuel setting to achieve best possible running
b. If using one of the Modelled Fuel Equation Modes adjust the Injector Flow Rate setting to achieve best
possible running, this will need to be changed back to the correct value later but works well for first
start purposes.
10. The engine should now be allowed to fully warm up. It may be necessary to readjust ‘Master’ several
times to maintain smooth running. Don’t forget to keep an eye on engine temperature.
11. Once the engine is warmed up and running well, perform another trigger calibration (known as “setting the
base timing”).
12. Perform a Store by pressing F4.
Essential Tuning Adjustments
It is assumed that at this stage all set-up procedures described in previous sections have been completed
and the engine is running. The following steps detail correct set-up procedures for some of the more critical
ECU parameters (note that MAP Sensor Calibration should have already been completed by now):
Injector Voltage (Dead-time) Correction
There is always a delay between the injector being energised and the injector actually opening. Likewise,
there is a small delay between the injector being de-energised and the injector closing. The opening time is
considerably longer than the closing time, however the overall result is that less fuel will flow for a given pulse
width than would be expected with an 'ideal injector'. To compensate for this the injector pulse widths are
increased to compensate for this 'dead-time'. The dead-time for a given injector is a function of the battery
voltage, differential fuel pressure and the type of injector driver (saturated or peak and hold). A typical dead-
time at 3 Bar differential fuel pressure and 14 volts is just under 1ms (ms = millisecond = 1 thousandth of a
second).
In applications with a linear 1:1 fuel pressure regulator (i.e. not a rising rate regulator), the differential fuel
pressure (difference between manifold pressure and fuel pressure) will be constant. Therefore the only variable
that is changing will be the battery voltage (this changes with electrical load and sometimes engine speed).
Without correction, the changes in dead-time will cause the engine to run lean when the voltage drops. If the
Injector Voltage Correction is properly set-up then changes in the battery voltage will not affect the air/fuel
ratio.
The injector dead-time table allows the dead-time for different battery voltages to be entered. The values
represent the dead-time in milliseconds. These should increase with falling system voltage.
Injector dead-time for a particular set of injectors can be determined using a flow bench or on a running
engine.
To determine the injector dead-time using a flow bench, the injectors need to be operated at the intended
operating pressure (normally three bar) and at a constant duty cycle as well as a set voltage. Vary the supply
voltage to the injector and measure minimum pulse width at which the injectors will flow for a particular
voltage. This is the required dead-time for that injector at that tested voltage.
To determine injector dead-time on a running engine, with the engine fully warmed and operating at stable
air/fuel ratios (a very precise AFR meter is required – a narrow band O2 sensor will not suffice), electrical
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