04-28-2017 | #11 |
Join Date: Mar 2014
Location: Warrington PA
Posts: 1,913
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Re: Minimum Air Idle Adjustment
Just removed the TB, on my way to get the 7mm hex bolt...making progress....
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Tom 1994 ZR-1 #009 "captured test fleet car" 1974 LS4 454 Vert 1982 L83 CFI...now a retired "dd"....Sold WAZOO Member |
08-07-2021 | #12 |
Join Date: Aug 2015
Location: Pittsburgh, PA
Posts: 152
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Re: Minimum Air Idle Adjustment
I know this is an old thread but just went through this procedure and it worked great for me so wanted to give a shout out to Dom and Phil for the procedure and tips. Thanks!
The only exception I ran into is that the 25mm long Hex head idle stop screw was a bit long in my case and the head was barely clearing one of the TB brackets when the throttles are almost full open so I used a 20mm long screw. When I started, my IAC counts were 30 at idle. Now they are 10-12. Thanks again.
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Roger 1990 ZR-1 #2699 Black on Black 15,000 miles Full-time secondaries, 4.10 gears, C-beam plates, ported top end |
08-08-2021 | #13 | |
Join Date: May 2007
Location: Chicagoland, IL
Posts: 9,687
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Re: Minimum Air Idle Adjustment
Quote:
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[SIGPIC][/SIGPIC]Former Membership Chairman Former ZR-1 Registry - BOD 1972 Corvette 4speed base Coupe SOLD long time ago 1984 Corvette Z-51/4+3 SOLD 1992 Corvette ZR-1 Aqua/Gray #474 SOLD 1992 Corvette ZR-1 Black Rose/Cognac #458 2014 Honda VFR Interceptor DX |
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08-08-2021 | #14 | |
Join Date: Aug 2015
Location: Pittsburgh, PA
Posts: 152
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Re: Minimum Air Idle Adjustment
Quote:
After finishing the idle setup yesterday, went for a drive today and drove perfectly - idle did not drop too low when taking my foot off the pedal and never died after an hour of driving and probably 2 dozen stops. One more thing I will mention is that my original throttle stop screw measured 7.6mm extension from the mounting tab. I installed the new Hex head screw about 8mm extension (because I wanted more air through primary blade/less IAC counts) and this put me within a half-turn of my final adjustment.
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Roger 1990 ZR-1 #2699 Black on Black 15,000 miles Full-time secondaries, 4.10 gears, C-beam plates, ported top end |
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2 Weeks Ago | #15 |
Join Date: Jan 2024
Location: Boston, MA
Posts: 126
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Re: Minimum Air Idle Adjustment
Digging up an old thread as I work through some stalling issues when coming to a stop before I go grab a data log. I realize this may be a "it depends" question, but is there a rough number of IAC steps one should expect to see with foot off the throttle at idle? I see BlackZR1 went from ~30 to 10-12 after following the procedure.
Thank you.
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1987: Z51 Coupe, Z51, 4+3, Yellow / Graphite 1994: ZR-1 #150, Admiral Blue / Black 2015: Z06 Coupe, Z07, M7, Arctic White / Red |
2 Weeks Ago | #16 |
Join Date: May 2007
Location: Chicagoland, IL
Posts: 9,687
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Re: Minimum Air Idle Adjustment
U want enough IAC steps so ECM has room to ?catch? idle drop, but not too many steps to where most of idle air is coming thru IAC opening. I typically shoot for 10-15 steps. One other step I do is to modify the IAC Min Air table in the calibration to match what the actual IAC counts are in operation.
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[SIGPIC][/SIGPIC]Former Membership Chairman Former ZR-1 Registry - BOD 1972 Corvette 4speed base Coupe SOLD long time ago 1984 Corvette Z-51/4+3 SOLD 1992 Corvette ZR-1 Aqua/Gray #474 SOLD 1992 Corvette ZR-1 Black Rose/Cognac #458 2014 Honda VFR Interceptor DX |
2 Weeks Ago | #17 | |
Join Date: Jan 2024
Location: Boston, MA
Posts: 126
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Re: Minimum Air Idle Adjustment
Quote:
On a cold start when the desired idle is still 1250 it looks like IAC is at 110. Once warm and desired idle of 850 the steps are around 30-40.
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1987: Z51 Coupe, Z51, 4+3, Yellow / Graphite 1994: ZR-1 #150, Admiral Blue / Black 2015: Z06 Coupe, Z07, M7, Arctic White / Red |
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2 Weeks Ago | #18 | |
Join Date: Jan 2024
Location: Boston, MA
Posts: 126
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Re: Minimum Air Idle Adjustment
Quote:
Looks like it is in my best interests to go through the IAC procedure anyway and see where I land. Currently it is mostly the same as the stock BMCB with a couple changes. Code:
Deg C / Deg F / Steps -40 / -40 / 95 -16 / 3 / 78 (Stock BCMB value is 90) 8 / 46 / 51 (Stock BCMB value is 32) 32 / 90 / 24 (Stock BCMB value is 12) 56 / 133 / 10 80 / 176 / 10 104 / 219 / 13 128 / 262 / 25 152 / 306 / 45 |
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