Precision Turbo and Engine BigStuff3 GEN3 PRO SEFI System Hardware & BigComm Software - Manual (Page 131)

BigStuff3 Pro SEFI System
Version 2.1 – February 2011 123
 GM LS1 (24x crank wheel) System Main Wire Harness -
http://bigstuff3.com/pdf/JMI-006-
016-CC_REV_B_GEN3_PRO_SEFI_LS1_MWH.pdf .
 Ford Modular Motor Main Wire Harness -
http://bigstuff3.com/pdf/JMI-006-031-
CC_REV_C_GEN3_PRO_SEFI_MOD_MWH.pdf .
 GM LS7 (58x crank wheel) Main Wire Harness -
http://bigstuff3.com/pdf/JMI-006-034-
CC_REV_B_GEN3_PRO_SEFI_LS7_MWH.pdf
The following additional system wire harnesses are also available in How To/Help section.
 DAE System Wire Harness
 16 Injector System Wire Harness
 24 Injector System Wire Harness
 NTK WBO2 for Methanol System Wire Harness
 GM Transmission System Wire Harness
 Injector Wire Harnesses for GM (Chrysler)/Ford/Buick applications
 Coil Wire Harnesses for the LS1 style and BigStuff3 “Hot” coils
89. Frequently Asked Questions
 What does working “On line” vs. “Off line” mean?
o Working “Off-line” = The BigStuff3 ECU is not powered up (PC Only). – The red ball
is moving in the upper right hand corner of the BigComm software.
o Working “On-line” = The BigStuff3 ECU is powered on, the communication cable is
connected between the GEN3 ECU and a PC, and the two are communicating with each
other – The
Green ball is moving in the upper right hand corner of the BigComm
software.
 The changes I make to cells in the table do not stay. What’s wrong?
o The PC’s
“Enter”
key must be depressed for changes to be temporarily saved. To
permanently save changes go to Save_Calibration section above.
 Should I use the camshaft position input (cam sync) with my distributor based GEN3 system?
o Without the camshaft position input (cam input connector in the main wire harness)
hooked up, the GEN3 system still provides sequential fuel injection and individual fuel
control per cylinder, but injector phasing (where the fuel is injected) and individual
spark control will not function.
 How can the GEN3 system provide sequential fuel injection and individual fuel control per
cylinder without the cam camshaft position input hooked up?
o When the engine starts cranking over, the GEN3 ECU begins firing the injector drivers,
assigned to each injector, in the firing order inputted into the software. What the GEN3
system cannot do without the cam camshaft position input hooked up is to determine
where to inject fuel (the position in crankshaft degrees, relative to TDC, for each
cylinder). Since the GEN3 system was designed with one injector driver per cylinder
(for up to 24 injectors!) it’s easy to see how individual fuel control per cylinder is
achieved.
 Why is the spark timing recorded in the Replay different from the timing configured in the
spark map?
o The Staged Boost control is active and there are spark retard values in one or more of
the three (3) spark retard tables under Boost Control.
o A similar situation will occur if the idle spark control is active at idle.