Do I need a hole in my TB

[5_Liter_Eater]

In a recent log my TPS is 20% at idle! Does the old hole drilled in the TB blade apply to ETC vehicles?

[Russ K]

Never drill a hole in the TB. The tps% can be lowered by increasing the base idle timing. My tps at idle is about 12% with a 234/228/.575 cam. My idle timing is 38*

Russ Kemp

[5_Liter_Eater]

38*?!? Wow. Mine is more like 10*. I tried using VCM controls to play with the timing at idle to obtain the least TPS and most manifold vacuum but the only thing not greyed out in VCM controls as far as timing is "Spark idle control - On or Off" and "Minus x degrees", can't add timing on the fly. So I guess I should just throw a bunch of timing at the initial tune and subtract from there. Maybe start at 40 in the idle cells?

What does Spark Idle Control do and should I leave it on or turn ig off?

[EC_Tune]

I think you will find the "happy place" somewhere around 32-35 degrees.