Precision Turbo and Engine BigStuff3 GEN3 PRO SEFI System Hardware & BigComm Software - Manual (Page 59)

BigStuff3 Pro SEFI System
Version 2.1 – February 2011 52
21. Firing Order
Once the Load and RPM axes have been configured, go back to the Configuration on the Tool Bar.
Left click on the “Configuration” and the drop down screen will open. Keep the left mouse button
depressed and slide the mouse pointer down until “Firing Order” is highlighted. Release the left
mouse button. The screen below will open.
Setting the Firing Order
To set the firing order, simply work from left to right and input the firing order of the engine the
system is installed on. The LS1 firing order (1-8-7-2-6-5-4-3) is shown in the example above. There
are specific injector wire harnesses for Chevy (Chrysler), Ford and Buick V6 engines. Make sure you
have correct injector wire harness type for your engine. For More information on injector wire harness
pin outs go to
Injector_Harness
22. Injector Opening Time
Next, go back to Configuration on the Tool Bar. Left click on the “Configuration” and the drop
down screen will open. Keep the left mouse button depressed and slide the mouse pointer down until
“Injector Opening Time” is highlighted. Release the left mouse button. The screen below will open.
The purpose of this table is to allow the user to configure the ECU to maintain a constant injector flow
rate with varying battery voltages.
Fuel injectors have a minimum pulse width (in milliseconds) required before they will open and let
fuel flow. For example, with a constant battery voltage of 13.4V, a 60 lb/hr. Bosch injector is not
likely to open until the ECU sends a pulse width command of 1.4 to 1.5 milliseconds (injector opening
time is also influenced by fuel pressure).