IAC steps

[tumleweed]

Is the proper IAC count to be achieved idling in gear or park? sorry

[dave w]

The attached .pdf should have helpful information on Tuning the TBI, including the IAC.

dave w

[steveo]

for your LT1? the important thing is that most of your idle air comes through the idle passages and not the throttle plates, so the LT1 should have its throttle plates pretty much completely closed.

there's no 'proper iac count' for an lt1, just an operating range. if there was, and yours didn't match, how would you achieve it? by tuning? raising and lowering idle speed itself? opening/closing the throttle plates?

i'd be worried if it's lower than 20 or higher than 100 in any condition.

if the IAC counts are too low, something is broken. if they're too high you probably need to enlarge the bypass hole in the throttle body to get more idle air.

you need the IAC to remain open a reasonable amount in all idling conditions, both park and neutral. above 0, it's open.

[tumleweed]

I can't get them any higher than 49 with the throttle plates all the way closed ( throttle lever not touching the stop screw) but I think I drilled the bypass hole. what is the original size of the bypass hole?

[steveo]

what's the lowest IAC count you've observed?

[tumleweed]

I can open the blades and get as low as 35-37 any further open and they start to go up