Precision Turbo and Engine BigStuff3 GEN3 PRO SEFI System Hardware & BigComm Software - Manual (Page 134)

BigStuff3 Pro SEFI System
Version 2.1 – February 2011 126
o The Timer Enable wire must be used.
o If there is a zero (0) timing retard value in any of the cells in the 3 timing retard tables,
the ECU will automatically revert to the base timing map.
 Can I use my three (3) stage Boost control feature to just retard the timing?
o Yes, but the criteria directly above must be met.
 I can’t get my LSx engine started. I’m using an LS2 sensor in the front of the engine.
o Swap pins A & C in the cam input connector around.
o In the Operating Configuration table, make sure you have correct pulses/rev value
inputted for your engine. LS1 engines have 24. LS2/7 engine have 60.Check with your
engine builder to be sure.
 My TPS sensor reads 100% when the throttle is closed and 0% when the throttle is fully
opened.
o Swap the wires A & C in the TPS connector. The engine may not start since the ECU
senses that the Clear flood Mode has been invoked.
 When I look at my replay, it shows timing values different from what is in my spark map. How
can this be?
o There may be values in the Boost timing retard tables. If there is 12V applied to pin A
of the boost connector (to enable DAI/Replay and the Timer Enable) the ECU will
invoke the timing retard values in the Boost timing retard tables.
 It seems like the timing I have inputted into my spark map, is not be realized when I make a
pass. What can be causing this?
o There may be values in the Boost timing retard tables. If there is 12V applied to pin A
of the boost connector (to enable DAI/Replay and the Timer Enable) the ECU will
invoke the timing retard values in the Boost timing retard tables.
 If I am tuning in Alpha/N mode (Hardware Configuration, then Control Algorithm) can I use
my 1 Bar MAP sensor for barometric compensation?
o Yes, the automatic barometric compensation is hard-coded in the ECU. Leave the MAP
sensor vacuum port exposed to the atmosphere. Do not plug the MAP vacuum port to
the intake manifold.
 How come I cannot see the active obelisk in my AFR, Spark, or Fuel maps?
o Both the Scaled Load and Scaled RPM signals must be selected in the Dash for each of
these tables.
 I have a new Windows Vista machine, and unlike my old XP machine, I cannot see the green or
red ball in the upper right hand corner of the BigComm screen. Why is this?
o Your PC must be running Window Vista Office Edition or higher, and Windows
“Transparency” box must not be checked (uncheck the box). The “Transparency”
check box is found in the Window Color and Appearance section. Go to Start/Control
Panel/Appearance & Personalization/Personalization/Window Color and Appearance.
 What do I need to do to make sure my 3-step works correctly? (assumes your system is
configured with the optional 2-Step and 3-Step)
o 12V must be applied to the DAE wire (Hdr 2, wire Y2)
o Apply 12V to the 2-step wire (Hdr 1, wire B2) via a line lock (manual trans), foot brake
or trans brake switch.
o With your foot still on the brake (assuming the foot brake switch is used to invoke the
2-step), Apply 12V to the 3-step wire Hdr 2, wire W1 (+ turbo speed wire in the DAE
harness). 12V is must be applied to this wire the moment the trans-brake is activated.
o Lastly, if you are planning to activate a traction control, staged timing retard or turn on
boost or nitrous solenoids in a timed sequence, 12V must be applied to the “Timer
enable the instant the trans brake is released. See
Three_Step_Relay_Wiring above.