Precision Turbo and Engine BigStuff3 GEN3 PRO SEFI System Hardware & BigComm Software - Manual (Page 84)

BigStuff3 Pro SEFI System
Version 2.1 – February 2011 77
Again this is an iterative process. If the timing values within the orange square above were to
be decreased from 30 degrees to 10 degrees all at once, the engine would die. To avoid this,
slowly work back and forth decreasing the timing and then opening the throttle blade with the
set screw until the engine idles at the desired RPM, with only about 10 degrees of spark timing
in the cells, below and around the obelisk.
5. From the main BigComm tool bar, go to “Idle” and then “Throttle Follower Table” in the drop
down.
6. Loosen the TPS (the settings to use if your TPS is not adjustable are covered below). Adjust the
TPS to 2% - 3%, so the obelisk is floating inside the first cell of the Throttle Follower Table.
Tighten the TPS sensor down. Make sure the desired IAC value (“
Des IAC ”) in the Dash is
decreasing towards the minimum value of 5.
7. If you are able to adjust the TPS, so that the obelisk is completely inside of the first cell, input
the values in the example table shown below, into your Throttle Follower Table. These values
represent a good starting point. Some additional fine adjustments may be required.
TPS % 0 8 16 24 32 40 48 56
IAC 5 44 88 111 122 133 144 150
If after adjusting the TPS, the obelisk is straddling the first two cells, input the values in the
example table shown below, into your Throttle Follower Table. These values represent a good
starting point. Some additional fine adjustments may be required.
In this example, the area within the orange
square is where the obelisk will be
floating when the engine is idling at
normal operating temperature. Working
back-and-forth between the spark table
and idle set screw, decrease the timing
values in this area to about 10 degrees,
while opening the throttle to maintain the
desired idle RPM.
The spark value in this cell should be set to about 22 to 24 degrees. This is the cold start
timing. It is used when the throttle is below the Max TPS for Idle calibration (Under
Operating Configuration) and when the coolant is below the Coolant AFR Temperature
(AFR Parameters) calibration. This helps with the cold engine fast idle function.