up2late76

i recently installed a set of thunder racing heads and a tr 224 cam. i noticed even before i sent them my PCM, the idle took slightly longer to return to idle after i take my foot off the gas <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" /> -light at a stop light or when slowly shifting(m6 car). any ideas? thanks...

NoGo

iTrader: (2)

A couple things to look at:

Vacuum leak. Check your intake and ensure that it is sitting properly. Make sure you don't have any leaks. Make sure all hoses in the back are connected properly. Make sure you brake booster hose is seated in the booster properly.

Drilled TB too large. If you had to drill your TB to get the cam to idle right, you may have drilled it too large. This will introduce excess air and cause the car to idle high or be slow returning to idle.

Good Luck,
<img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />

Predator

To add to NoGo's vacuum section: if you removed your AIR system, you have to cap off the vacuum inlet, that the AIR system vacuum hose goes into, in the back of the intake manifold (if you haven't already).

up2late76

i'm gonna subscribe to the TB hole being to large. i did have to enlarge it to get the car to idle, my IAC counts were like 23 or 25ish, alittle to low i think. should be be around 30 or 40 if i'm not mistaken. but it isn't that bad, just a little slower than stock. if it won't hurt anything, i'll just deal w/ it...

dand35th

try closing the throttle blade a little. as long as it starts fine when hot/cold you can't go too far.

up2late76

hmmm, i didn't know you could close it more. i thought you could only open it up if it hasn't been touched yet...

dand35th

Of course DON'T go too far closed, so the blade is pinned in the TB. Or the set screw doesn't hit!!

horsepower

if the idle comes down only when you get to a complete stop, you are encountering the throttle follower. With the latest version of ls1edit you can tune it correct. I have run into this before.

Stu

With Edit I used the Idle air in gear table to stop it.

I just gradually stepped it down at warmer temps till it Quit.

Good luck, Stu

49203

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by horsepower:
<strong>if the idle comes down only when you get to a complete stop, you are encountering the throttle follower. With the latest version of ls1edit you can tune it correct. I have run into this before.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">

49203

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by horsepower:
<strong>if the idle comes down only when you get to a complete stop, you are encountering the throttle follower. With the latest version of ls1edit you can tune it correct. I have run into this before.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I have the problem on my 2002 SS m6. Downshifting it will usually stay at whatever RPM the engine came in at on the shift to the lower gear, and stay there for 3-4 secnds, then slowly come down for another 3-4 seconds, then finally drop down as you would expect it should have in the first place. Another hint might be the gas mileage - I have not gotten over 14.5 in the 2500 miles i have put on the car. Any thoughts/ideas?

nitrousc5

The Throttle Decay/delay will help the slow-to-decay problem. Remember, put a few miles on in between tunes to really see what you have affected. that is one thing i have learned with Edit; be patient, put some miles on the car.