Precision Turbo and Engine BigStuff3 GEN3 Powertrain Controller Ignition Setup Tutorial - Manual (Page 32)

With COP engines using HED cam and crank sensors, like the GM LSx engines, the synchronization
status is provided immediately during cranking, so there is no need to rev the engine to 2000 rpm.
If the synchronizer ball is gray and is rotating eccentrically within the box, the cam signal is occurring
before the crank signal. However, if the ball turns red, a problem exists, since the cam signal is
occurring at the same time as the crank signal. To alleviate this problem, the cam sync sensor needs to
be replaced, or modified so that the cam sync pulse occurs before the crank signal. Contact BigStuff3
for further assistance. For distributor based engines, move the cam sync drive or the crank trigger
sensor so that the cam pulse occurs before the crank pulse.
Note: The individual cylinder timing retard still needs to be verified, even though the synchronizer is
gray. This is just a quick test to see if synchronization is taking place. See
Verifying_Synchronization
on page 11.
Cam Sync Error Flag
Note: The cam sync signal must never occur at the same time as the crank trigger signal. If this
occurs, (e.g. due to belt stretch or cam sensor misplacement) the ECU can record this in the Replay
data log and will set the “Cam_Sync” error flag (see BigComm Replay in GEN3 User’s Manual).
Once the Cam_Sync error is set, the individual cylinder timing corrections could jump to the wrong
cylinder causing engine misfire. If a Cam_Sync error flag is set, the cam and/or crank sensors need to
be adjusted so that the cam signal occurs before the crank signal.
MSD8 Pull-up Resistor with BigStuff3 GEN3 System
900 Ohm (850 Ohm
min), .125 Watt (2
Watt max) pull-up
resistor
Ignition
BS3 “Points”
wire from Main
wire harness
Mag +
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