Ryoga

TTT - Anyone?

LS1derfull

Drilling hole in TB blade is only a way of raising idle speed with out cracking idle speed setting open further. Reason people do it this way is to keep TPS from seeing higher voltage at idle that will set SES code for too hi a reading, when idle speed set screw is used. You get hi idle while coasting closed throttle because pcm is trying to keep closed throttle running from being overly rich, this is normal operation, it only shows up as noticeable because cammed cars with higher idle speeds arent recognized and compensated for by stock pcm. The bottom line is you need to set your idle speed for clean hot motor restarts, which should end up at about 850 in gear. Drill Tb hole some and adjust the rest with idle set screw. You can go as high as 875 with out setting hi idle speed DTC.A/c usage with
A4 is touchy situation, since you have LS1EdIt you might try giving motor more timing at idle with previuosly set idle speeds, this will allow more horsepower at idle and less chance of stalling. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

Ryoga

Lately there has been a good bit of jumbled information and Q/A's concerning drilling the Throtle body and Idle with cams, but none really seem to talk about whether or not there is a 'good enough' range or exactly what DOES happen if yo udrill too much, and lastly whether or not you just have to learn to deal with a certain amount of stalling....

I've been trying to fine tune my idle as best as I can since the Head/Cam install and have a couple questions before I go any further. The cam I'm running is the T1 (221/221 558/558 112lsa) and my car is an A4 with a Super Yank 3500 converter. With EDIT, I've currently set my idle at 850 (which for an auto is a lot higher than before anyhow). During the post install the IAC was reading about 130-160ish (I can't recall exactly) but the car simply would not idle. I used a 1/4 inch drill bit to drill the throttle body hole and then tested again. The car idled fine so I left it. The IAC's run about 90-95ish now. With that said I've noticed when the car is coasting with 0% throttle it sits about 1050/1100 rpm mostly (which I'm guessing is normal, never paid attention before). Now, since I've done all this the car seems to only stall out maybe 5 out of the 100 times I've driven it (and every time it did, it was related to the AC being turned out and during the transfer from P to Drive).

So that's the data... Now my question. If I go ahead and drill the hole up more until I see 30's on the IAC, what will the impact be? Will this pretty much clear up the occurrence of my infrequent stalling? Can I then possibly drop the idle to 750-800? And last but not least, will the coasting idle increase as a result?

<small>[ July 29, 2002, 12:42 PM: Message edited by: Ryoga ]</small>