Precision Turbo and Engine BigStuff3 GEN3 PRO SEFI System Hardware & BigComm Software User Manual
Page 132
BigStuff3 Pro SEFI System
Version 2.1 – February 2011
124
Will the GEN3 ECU drive high and low impedance injectors?
o
Yes, it can drive both high and low impedance injectors. The GEN3 ECU can even
drive both injector types of injectors simultaneously with the 16 or 24 injector options.
The GEN3 ECU auto-detects the type of injector being used, so no set up is necessary.
At what injector duty cycle % are my injectors considered out of control, or static?
o
Loss of injector control does not occur at 100% duty cycle, but at approximately 85%
duty cycle. At 85% duty cycle the injectors are most likely not opening and closing in a
controlled fashion. This condition is termed “static” (vs. dynamic) control. An
example why this condition is undesirable is if the GEN3 ECU demands more fuel
(demanding a larger pulse width) and the injector is already static. The only way to
move more fuel through the injector would be to increase the fuel pressure. Increasing
the fuel pressure at the 1/8
th
mile marker is not possible, so things go bad quickly. Also,
teetering on and off at the static point is also undesirable. Lastly, running the injectors
drivers static for long periods of time can damage them.
How do I set up my ignition system with the GEN3 system?
o
For more information on ignition system setups, beyond what is available in this
manual, go to the How To/Help section on the BigStuff3 website, and then Ignition
System Setup Tutorial. The link is:
. There are nine (9)
ignition system setups outlined. There is also information on the setting up the Ford
TFI, GM HEI, GM Opti-spark & MSD8 ignition systems in the How To/Help section of
the website..
Where can I find wiring harness information on the BS3 power-train system and optional
systems?
o
Information on most of our wiring harnesses is available on our website at
www.bigstuff3.com. Go to the How To/Help section on the website. The first fourteen
(14) files listed in this section are wiring diagrams. The link is:
.
My engine will not start. What should I check?
o
Make sure the harness side header connectors, interfacing with the GEN3 ECU, are
attached and tightened to no more than 15 – 20 inch lbs.
o
Make sure the battery voltage is at, or above, 12V during cranking. Low battery
voltage conditions must be fixed before trying to start the engine. Battery voltage
(especially during cranking) is even more important with coil-on-plug applications.
o
Make sure you can see an RPM signal in the Dash. While turning the engine over, you
should see at least 100 – 150 RPM. If no RPM signal is present, check that the crank
input (crank trigger or distributor) signal wire is connected to the red wire in the BS3
“Crank” connector. Swap the 2 wires and try again.
o
For distributor ignition based applications, make sure the BS3 points wire is connected
to the ignition system points input terminal/wire. Applying 12V directly to the BS3
points wire will immediately damage the GEN3 ECU!!
o
For COP engines (LSx and other standalone COP engine) the cam input cannot occur at
the same time as the crank input!!! If this is the case, the engine will not start. The cam
synch pulse must occur before a crank pulse. Ideally, 10
O
before the crank pulse. For
more information on ignition system setups, go to the How To/Help section on the BS3
website, then to Ignition System Setup Tutorial.
o
With all coil-on-plug engines, make sure the coil ground eyelet is securely fastened to
the cylinder head or engine block. No other grounds locations should be used.