Fuel System

Fuel System

Fuel System

This page is used to configure the Fuel Injection System.

Injection System

Disable Injectors

Enabling this will disable all injector outputs. (Default = Disabled)

Enable Short Pulse Width Adder

Enabling this will add a Short Pulse Width Adder table per injection stage. This adder is used to increase the actual pulsewidth at the injector when the injector is operating in its non-linear fuel delivery range. For more information see 'Fuel Tuning' > 'Stage' > 'Short Pulse Width Adder'.

Injector Timing Method

Selects the timing of the injection pulse in relation to TDC. Either timed to the start of the injection pulse, or timed to the end of the injection pulse. Default = End of Injection.

         Number of Stages

          The number of separate fuel injector stages that are to be used.

Cylinder and Bank Correction Stages

This sets how the ECU applies cylinder and/or bank fuel corrections. In some applications, its not possible to deliver per-cylinder or per-bank corrections if the fuel from a stage's injectors affects all cylinders. Therefore you should only set this to injection stages that have per-cylinder fuel injectors.

Staging Method (Elite ECUs Only)

This selects the staging mode when multiple stages of injection are being controlled. 
Nexus Style: Recommended for new Elite installations, when the fueling hasn't been tuned yet. 
 - First stage only until it reaches Stage 1 Staging Duty Cycle. 
 - Then the first stage holds at Stage 1 Staging Duty Cycle, and the next stage starts ramping in. 
 - This is repeated for all further stages. 
 - If all stages are at their Staging Duty Cycle and more fuel is required, then all stages will increase their duty cycle up to 100%. The rate of increase may differ between stages such that all stages reach 100% duty cycle at the same time.

If Stage Flow Percentage Tables is enabled: 
 - Flow Percentage tables control how much of the total fuel usage gets injected per stage, up to the Staging Duty Cycle. 
 - Once a stage has reached its Staging Duty Cycle, the excess will be distributed to other stages instead. 
 - Once all stages reach their Staging Duty Cycle, they will all increase, possibly at different rates, so that they all reach 100% at the same time. 
 - Setting all tables to 0% results in the same behavior as having Stage Flow Percentage Tables disabled.

Elite Style (Legacy): only recommended if your fueling has already been tuned with Elite Style staging. 
 - All active stages use the same duty cycle. 
 - The number of active stages increases when the highest active stage duty cycle exceeds the Max Duty Cycle setting. 
 - The number of active stages decreases when the highest active stage duty cycle goes below the Min Duty Cycle setting. 
 - If you are going to tune the fuel, it is recommended to change to Nexus Style.

Stage Flow Percentage Tables

This enables the per-stage flow percentage tables, also known as flow proportion. This gives the tuner much finer control over the amount of fuel delivered from each fuel injection stage. These tables are found in each Stage's Fuel Tuning node. More information on Stage Flow Percentage can be found in the Fuel Tuning > Stage help.

Staging Set Up

Stages (1 - 4)

Configuration for each of the enabled stages.

# Of Injector Outputs

The number of physical injector outputs used for each stage.

Injection Mode

The injection delivery method for each stage. (Default = Sequential)

Sequential

Each injector output fires once per engine cycle and is timed with its associated cylinder. The full calculated fuel amount is delivered per injection event. This setting requires a Trigger Type that supports full engine cycle synchronization, typically with a crank and a cam position sensor. This is the preferred injection mode for all engines.

Semi-Sequential

Each injector output fires twice per engine cycle (once per crank rotation) and is timed with its associated cylinder pair. Half of the calculated fuel amount is delivered per injection event. This setting requires at minimum a Half Sync Trigger Type such as a crank-only trigger (eg. missing tooth triggers with no cam position sensor). Typically used when there are not enough injector outputs for all injectors.

Common injector pairings are as follows:


Cylinder Pairs



Firing Order
Output 1
Output 2
Output 3
Output 4
1-3-4-2 / 1-2-4-3
1 4
2 3


1-3-2-4 / 1-4-2-3
1 2
3 4


1-4-3-2
1 3
2 4


1-5-3-6-2-4
1 6
2 5
3 4

1-2-3-4-5-6
1 4
2 5
3 6

1-6-5-4-3-2
1 4
3 6
2 5

1-8-4-3-6-5-7-2 / 1-8-7-2-6-5-4-3
1 6
5 8
4 7
2 3
1-3-7-2-6-5-4-8
1 6
3 5
4 7
2 8

Injector wiring can also be confirmed by checking the Fuel System > Wiring node.

Multi-Point

All injector outputs are fired together. This setting only requires a Trigger Type with one trigger per spark event. Enabling this setting in turn enables the Injections Per Cycle setting.

Batch

Injector outputs are divided into two groups which are fired alternately. This setting only requires a Trigger Type with one trigger per spark event. Enabling this setting in turn enables the Injections Per Cycle setting.

    • Related Articles

    • Primary Fuel Density

      Primary Fuel Density This table is used to set the density of the primary fuel used in the ECU fuel volume delivery calculations. Default = 737.2 kg/m3 (Gasoline/Petrol) The table is enabled when the Fuel Type is set to Petrol, Flex Fuel, or Ethanol ...

    • Fuel Tuning

      The Fuel Tuning node configures the main Fuel Tuning related information for the engine. Fuel Tuning Method Sets the method for fueling calculation. Most installations will use Volumetric Efficiency. See also Fuel Base. Auto V.E Air Temp Compensation ...

    • Trigger System

      Engine Configuration - Trigger System Page This section contains setup information for configuring your engines' trigger system, including crank and cam trigger patterns and sensors. Select Trigger System This button allows automatic selection of ...

    • Fuel Pressure Sensor

      A Fuel Pressure Sensor can be used with your ECU for datalogging, injector pressure differential tuning and for Engine Protection purposes. A Fuel Pressure Sensor is a powered sensor that typically has three wires; a 5V+ power wire, a signal wire to ...

    • Why you need a Fuel Pressure Regulator

      A modern port fuel-injected engine has an electric fuel pump that feeds fuel from the fuel tank, up to the front of the car and through the fuel rails (which house the fuel injectors), through the fuel pressure regulator, then back the fuel tank. A ...