IAC install

[1967 GeeTO]

Is there anything special when replacing the IAC (mine broke while removing it to clean it)? After I insalled the new one, the numbers were way off - somewhere around 100 at idle with the tps at .40-.42 per my Scanmaster. I tinkered with it and the tps for about an hour and am getting the numbers closer, but still have more adjustments to make. Is this normal? Does it matter how much you tighten the IAC down as long as it is tight?

Also, what should approximate rpm be at idle? I'm getting the numbers closer, but sometimes turning a high idle rpm (1500).

Thanks, Sam Williford

 

[OneLethal87GN]

Go to www.gnttype.org and do a search for IAC valve setting.

 

[TurboRegal84]

Your RPM idle is controlled by the computer/chip....These cars usually idle around 750-850 RPM.

Your idle stop screw (located on throttle body) is used to adjust the IAC counts. The screw should be turned slowly to allow the computer/IAC to compensate for the the adjustment. After every turn on the IAC you should adjust the TPS. Go back and forth till you get your numbers into close range.

 

[1967 GeeTO]

Ok. I did my research before I posted my originial question and have done more since then. The only info I can find on gnttype.org and this board says to turn the IAC adjustment screw to bring the IAC count within range. After bringing the tps in line (.40-.42 at idle and 4.5-4.75 at WOT) the IAC's are very low. I have gotten the numbers up to 05 and that's at 1800 rpm per the stock tach. At this rate the car will idle at 3500 before the IAC hits 20. Surely this is not the correct way to get the IAC set.

I assume Advance Auto sold me the correct IAC. The clerk looked it up on the computer. Is there any checking the IAC before you install it, like gapping a spark plug? Is there any special install procedure? Thanks again, Sam.

 

[TurboRegal84]

Sam,

The Stock Tach is about as accurate as sticking your head out the window to see how fast you are going!

Any Turbo Regal buddy's in your area that you can borrow a ScanMaster from? What are you using to read the IAC numbers?

 

[1967 GeeTO]

I have a Scanmaster 2.1. Does it register rpm? I can tell that the car was idling too high as I got the IAC numbers up to 05. I will make the adjustments, turn off the car, unplug the orange computer wire and start again. After another half hour of adjusting last night, I still can't get the numbers right. The car was ok before I replaced the old IAC so I am convinced it is either the new IAC or my installation - most likely my installation.

 

[TurboRegal84]

Yes, Scanmaster had a mode that displays your RPM!