Another Throttle Body Question, Adjustment screw Options

[914Rookie]

What is a rough baseline adjustment for the screw in the throttle body? how far should it be backed off from fully closed ?. (IMG:http://www.914world.com/bbs2/html/emoticons/huh.gif) I think mine is so far off it's causing other problems. Also, how many "clicks" from stopped should the box be. Thanks. (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif)

Greg

[914Rookie]

Forget to give some important info. Car is '75 2.0

[redshift]

The brain isn't something you can just say '5 clicks'.. someone can explain that better... mine is about in the middle of travel, and it's set just a click higher than it needs to be.

Your idle may hunt if it's low (lean)

Now, the idle adjustment is easy, it's screwed out enough to keep the idle @ 950rpm... but..

to test, you must warm the car up fully, and defeat the AAR (search here if you are unfamiliar) by plugging (with a stopper) the INTAKE hose feeding it, after removing that end of the hose from your airbox.

If your AAR is in any failure mode that keeps it partially open, it won't be right. (unmetered air, high idle, with idle adjust screwed in all the way)

What's the symptoms?


M

[914Rookie]

Thanks redshift,

symptoms are idle way too high, and when trying to lower via the adjustment screw it seems to go right past 950 rpm to too low then stalls. This was not a problem before I started screwing around with the adjustment screw. I changed a couple vacuum hoses so that these are now leak free. But none of this was done with the car at proper temps. I'll check the AAR but it has run fine 'til I turned the screw. (IMG:http://www.914world.com/bbs2/html/emoticons/blink.gif)

[mattillac]

i think there should be a mark on the ECU box corresponding to where the screw should be turned to. you might not be able to see it if your ecu is really dirty.

[redshift]

Yes, Matt is right..

There is a point on the collar, and a melted notch groove in the knob on the brain. At the factory, they started (completed car, tuned, notched) notch at point.

I don't have to tell you that your milage might vary... right? (IMG:http://www.914world.com/bbs2/html/emoticons/smile.gif)

I actually looked, mine likes point +three clicks. (clockwise, north of the equator)


M

[914Rookie]

Now the car won't idle at all (IMG:http://www.914world.com/bbs2/html/emoticons/mad.gif) . CHecked the AAR and it seems to work properly ( I can blow air through when cold but not when engine is warm ). I will try tomorrow adjusting when warm.