Need help with high idle issue

[Hardtop00SS]

I've been having this problem since I ran at my local drag strip about 3 weeks ago, ran it down the 1/4, as I was slowing down the car was doing the cruise control thing, I figured it would stop once I parked, well stayed at about 1400. I've checked everything, all the vacuum lines, intake for leaks (sprayed starting fluid around the base), checked the throttle linkage well I went out there last week and started it up and it was idling at 1400, so I unplugged the TPS switch, and the idle dropped back to normal, so I figured the TPS switch was bad because I also check the TPS when the car was off and it was reading 1%. So I changed the TPS out and the car ran awesome when it was cold, but once you started driving it and it warmed, up started to do the cruise control effect again but the idle would come down after a little bit. I am at a lose on what do to now, I'm new to tuning so I'm not really sharp on idle tuning but I followed the method on here and also on LS1 tuning.com. It still doing the cruise effect but not as bad, I can't figure out what to change on the idle tune. Can anyone point me the right direction?? Been fighting with this car for 3 weeks and haven't gotten anywhere. BTW the car has an LS6 intake on with new gaskets I installed about 5 months ago and I also have an MTI TB.

[Hardtop00SS]

come on, nobody has any advice??

[luv2spd]

Cruise control effect is often from having too much idle air. Try reducing the raf and see if that helps.

[Hardtop00SS]

how much should I reduce the table?? I'm a newb to this so I am learning as I go.

[torchredfrc]

I've been having this problem since I ran at my local drag strip about 3 weeks ago, ran it down the 1/4, as I was slowing down the car was doing the cruise control thing, I figured it would stop once I parked, well stayed at about 1400. I've checked everything, all the vacuum lines, intake for leaks (sprayed starting fluid around the base), checked the throttle linkage well I went out there last week and started it up and it was idling at 1400, so I unplugged the TPS switch, and the idle dropped back to normal, so I figured the TPS switch was bad because I also check the TPS when the car was off and it was reading 1%. So I changed the TPS out and the car ran awesome when it was cold, but once you started driving it and it warmed, up started to do the cruise control effect again but the idle would come down after a little bit. I am at a lose on what do to now, I'm new to tuning so I'm not really sharp on idle tuning but I followed the method on here and also on LS1 tuning.com. It still doing the cruise effect but not as bad, I can't figure out what to change on the idle tune. Can anyone point me the right direction?? Been fighting with this car for 3 weeks and haven't gotten anywhere. BTW the car has an LS6 intake on with new gaskets I installed about 5 months ago and I also have an MTI TB.

I am experiencing the same problem but only on cold startup. I'll drive to the end of the road and put in the clutch and the rpm's will only drop to 1400-1500 then will settle at my 900 idle. Subscribing to this thread... I hope someone else has solved this.

I have the following mods installed:
MTI C2 (old grind) cam shaft
LS6 intake
LG Long tubes (recently added, did it before & after LT)

[luv2spd]

how much should I reduce the table?? I'm a newb to this so I am learning as I go.

Try reducing it by like .5 or 1 and see if it helps. What are your current values?

[Hardtop00SS]

I feel like an idiot, I still can't find the RAF table, any help??

[luv2spd]

Well, I guess in hpt its called something else. Go to the idle tab, then Idle Airflow, and its called base running airflow.

[Hardtop00SS]

alright well I've made progress, I adjusted my idle screw on the TB and it brought up my IAC counts to about 25 when fully warm, but now it surges on cold start ups, it still does the cruise control, but not nearly as bad, it hangs at about 1100 then drops when I come to a stop, but overall it's getting better. I'm assuming I need to bump up my IAC counts to about 50 or 60, do I need to do this with the idle screw?? Also, I know after adjusting my idle screw I have to change some perameter's but I can't remember which one.

[99Zee28]

I am new at this but I am trying to work out the same problem. I have searched all through these forums several nights until I can't keep my eyes open! I don't think the Idle screw should be adjusted. I have found a few posts that tell you how to set the idle up after a cam install which is what I need. Have you installed a different cam? What is your MAP reading? I think you should try scanning the LTIT's and STIT's (Idle Trims). There are two Long Term Idle Trims in gear, and in park. There is also a Short Term that works off the LTIT and the Base Running Airflow Table. If you will start the scanner and insert these PID's and scan until the vehicle warms up. You want to scan LTIT's, STIT, and ECT so you can keep up with the correction its making at each ECT block on the base air table. Leave in park the entire time and keep foot off gas. When its warmed up let it idle a couple more min. and then you look at the scan. I like to play mine back and write down the LTIT in park/Neutral at each ECT Cell , If its -2.15 at 180 deg then you go to base air table and find the block that 180 deg falls into and subtract (or add if its Positive)it from the park/neutral cell. After you make the changes to the park/neutral table in as many ECT cells you can get readings for you need to let it cool back down and do it in Drive with foot on the brake not moving. You might have two go through the whole process twice to get it right. I think there will always be a little correction but the idea is to get it close. You will also need to change the Idle Trims on the scanner to Metric so you don't have to figure later. You do that by left click on the cell then right click and select Metric. Also make sure ECT Cell is Imperial not Metric! Hope this helps! You might also check to see what your Idle speed is set at! If this does not fix it and you find something that does then please let me know!