Well for about 5 months i've been battling a 500 rpm idle( when warmed up) and even lower when accesories were turned on. Here are some of the things i tried to get my idle up these past 5 months:

IDLE BLEED SCREW-which only could adjust up to 500 rpm with set connector grounded engine completely warm of course.

TPS- adjusted to 1vdc, key on, engine warm- this did make the engine run a bit smoother....but still no help with low idle.

Vacuum leaks- many a can of brake clean on this one and none found plus the engine pulls a steady 18in hg at idle so no problem there

BAC- removed bac from engine ohmed 12.3 ohms, key on with bac connected inner piston does vibrate so no proble there. Even cleaned bac. no help

OK so none of the above helped with my specific idle concern helped the engine run a little better but here is what FIXED my low idle:

IDLE STOP SCREW- the one that rests against the primary throttle when it is at rest. I adjusted the screw with the lock nut, one turn in and put the throttle body back together and can you believe it a perfect 750 rock solid idle. I don't know if that screw has ever been messed with before or not and there is no procedure in the fsm to adjust this screw but this is what has fixed my low idle...i also went back and adjusted the tps again seeing that moving the throttle plate moves the tps and i reset the idle bleed screw.

I hope this may help anyone that has had a low idle problem. The car runs great now, its been about a week no change in solid idle.

I just have one question to someone that knows anything what im talking about is that by changing the throttle angle slightly and reajusting the tps could this have a great affect on fuel maping or create a lean condition or anything like that???? THANKS

 

Nice job...

 

I'm still wondering why your BAC never kicked in to bring the idle up to 750?

Did you check the BAC's output at the ECU?

Don't think that small tweak on the throttle stop you did should screw with your fuel scheduling TOO much...

 

do you have a n/a or T2

 

s5n/a Yea thats what i was wondering too wayne. I never did check the voltage from the ecu.. i did install a reman ecu in and still nothing.

About 5 months ago i asked Hailers if there was an fsm adjustment for the throttle stop screw and he said no. But he said that he had a s4 throttle body with the gunk still left in the adjustments screws and that when the fast idle cam was lifted of the roller the primary throttle plate closed fully and rested on the primary throttle screw. Now whether or not there was a small gap between the primary throttle plate and the bore that he could not see, who knows. All i know is that the idle is solid now at 750.