1986 NA
I upgraded to an S5 intake and removed all of the emissions stuff and rats nest. The car starts up and runs fine but will not Idle at all. I can hold my foot on the pedal and it will run fine at around 1000 rpm I lift my foot and it dies. I have checked all grounds and for vaccuum leaks no problem there. Any other ideas... I have tried adjusting the idle screw on top of the TB but it made no difference. I am just running an open header for now since I haven't had time to fab up an exhuast.
I was thinking about just building an adjustable bracket that I can hold the the throttle open were it will idle. Does anyone else have any good ideas or possible problems I could have over looked.

 

Well if you removed all your emissions and in the process decided your car doesn't need the bypass air control valve (BAC) and did the "throttle body mod" then yes, the car won't idle since you have no idle assists anymore. Now, for the solution, if you are 100% sure you have no vacuum leaks and all hoses are routed correctly, and you did in fact remove the those things I listed that make your car driveable, you can adjust the throttle cable on the mount that holds it in place before the throttle body.

Adjusting the nuts, pull the cable just enough to get it to idle where you want it, go for a drive, and check it stays in the same idle range. Adjust as necesarry.

 

I have the same issue, but mine does idle after warming up...

 

wouldnt adjusting the throttle stop be easier?

 

Yes... to each his own....

 

Yes. Because on a cold engine, more fuel is needed. And our cars love to pump fuel into the motor when it's cold. But a rich mixture means a low idle, hence the engine stalls out. You need need some extra air too, to keep that idle steady. But how!? Put the BAC valve back on.

As the car warms up, the coolant corrections go away and the mixture is leaned out. Hence the car will idle fine when it's warm as it does not need the extra air from the BAC anymore.

The thermowax also helps, as does the air control valve. But it can be done with just a BAC (I run this on my ported turbo).

Worst case if you aren't running anything, you can just tighten the idle screw all the way in (like mentioned). It may idle cold, but as it warms up, you're idle is going to rise.

 

Thanks for all the help