Id really like to get my cammed ls1 idling reliably at 850-900 rpms. I have read guides to do this but they confuse me as i have not found a step by step one. My counts are way high and I am having trouble. My VE table is in check as far as driving and WOT, I have all the other factors tuned and such, timing is good.

At this point I have adjusted the set screw a bit and set the idle to 1200 and it idles ok but the counts are still high. I would like to lower the idle back down. I know it is possible but I am a bit lost. I have searched and I still am confused.

So lets say i start with a fresh tune and once i got my ve table in check and all the driving stuff, what is a basic step by step guide to fixing up my idle?

 

http://www.hptuners.com/forum/showthread.php?t=4591

http://www.hptuners.com/forum/showthread.php?t=8274

 

But ive always been told, a proper tune does not need to drill a hole. Ive heard that a hole can cause problems as well.

 

You should shoot down to Lansing one weekend and we could work on it.

 

start with base airflow table. if its wrong the rest of it will be hard to do.

 

Unfortunately, idle is the first thing we want our engines to do, and one of the more complex/advanced tuning concepts you can encounter. Here's an excellent thread with idle tuning basics. http://www.forum.efilive.com/showthread.php?t=4661

 

-Set idle at 900 RPM>Idle>Idle RPM

-If throttle body has bad port job it will never idle right I have seen everything from blocked IAC's with JB weld to TB's that open to far causing a lean condition at WOT 4.7 volts

-Set your base airflow numbers initially 4-5 gm/sec higher Idle>Idle Airflow>Base Running Airflow something like 11-12 gm/sec warm

-Then adjust your set screw up until you get 80 IAC steps. They say you don't want IAC counts with the AC off below 60 counts.

-I would start with a open loop idle-makes sure you get your AFR 14.0 idle with wideband at operating temp. And then reset your LTFT with bi-directional controls. That is post #13 MNR-0 http://www.hptuners.com/forum/showthread.php?t=7591

-Make sure spark at idle is 21-27 degrees>Spark Control>Idle Spark advance

-Set Spark control>Spark advance>ECT spark base. Make the negative numbers in this table 0 so when it is cold it don't pull timing.

-IAC park position airflow controls your initial flare on start up so adjust accordingly Idle>Idle airflow>IAC park position airflow. If it flares to much lower gm/sec if not high enough raise depending ECT. I believe they used to say everything 40C and above make 21 gm/sec but that might be too much.

-Use your histogram feature for Idle>Idle airflow> Base Running Airflow. Every time you do you have to let car cool all the way down and start the histogram feature over until you get idle trims to zero perfect.
http://www.hptuners.com/help/
Working with VCM scanner>Displays>Histogram

-And if you can't get consistant LT trims for idle try changing your tune to like the red boxes in the pic attached.

- http://www.hptuners.com/forum/showthread.php?t=4591 Look at post #26 Ken@HPTuners gives alot of info on how the idle control works for the LS1 if you read it a few times.

I have had best luck with this maybe some others have some good ideas also. HP Tuners is really good software if you take the time to learn all of it's functions and you can learn alot if you take the time to read their forums.


This is a pic from EC_Tune on the www.hptuners.com forum

 

Wow, that's some good info.

 

Not running a open loop idle with headers has kicked my *** a few times.

 

Yeah, I've been ignoring my idle issues for about a year now. My laptop busted and i've been lazy. I'll try a few of these to see if it works. I have a relatively small cam 224/224 112 560lift, but now i'm getting annoyed, I'll report back the things that worked.