Vacuum leak or is the tune off??
Thread Starter
Joined: Sep 2003
Posts: 1,199
Likes: 0
From: Richmond, VA
Vacuum leak or is the tune off?? Well I've been fighting with my car for about a month now and I still can't figure out what the problem is with it, I've been having a high idle problem since I raced it one night at the drag strip. The car was idling at about 1400 on a cold and warm startup, so I fooled with it one and unplugged the TPS sensor when it was running and the idle went down, so I changed the TPS sensor and the car would idle fine on a cold start up, now when I start the car up, let it warm up, cut it off, then start it up again, the idle is all over the place, you will hit the gas when the car isn't moving and the idle will hang at about 2000 and SLOWLY drop down. I have the idle set at 950, but the idle won't drop below 1100, I've swapped out the IAC motor and that didn't fix it either. I was thinking that it may be a vacuum leak, and once the car heats up, where ever the leak is, it's expanding and causing the high idle, but I've sprayed starting fluid all over the base of the intake and all over the intake and the idle didn't change, checked all the vacuum lines and throttle linkage, everything looks good. I've tried to change my table in my HP Tuner scanner mode to view the IAC counts but the table won't change, I've been uploading multiple tunes in this thing in a attempt to fix the idle and nothing has worked, can anyone help me out, maybe take a look at my tuner file and change it accordingly?? I've been reading threads for a month on how to fix the idle on a heads/cam car and nothing has worked. BTW I have a LS6 manifold and a MTI TB, both have been on the car for about 4 months.
Thanks
Thanks
Thread Starter
Joined: Sep 2003
Posts: 1,199
Likes: 0
From: Richmond, VA
I followed that, but I can't figure out how to configure my scanner table to read the IAC counts. I have HPTuner's, tried to make a new config for idle tuning, but the table won't show up, also what is RAF? I'm a newb to tuning so I am learning as I go.....
Originally Posted by Hardtop00SS
I followed that, but I can't figure out how to configure my scanner table to read the IAC counts. I have HPTuner's, tried to make a new config for idle tuning, but the table won't show up, also what is RAF? I'm a newb to tuning so I am learning as I go.....
RAF is Running Airflow table and it's responsible for a lot of 'off throttle' behaviors, so it's very important to drivability.
Thread Starter
Joined: Sep 2003
Posts: 1,199
Likes: 0
From: Richmond, VA
Originally Posted by RedHardSupra
IAC Position and IAC Desired Position is what you want, you can find it under Insert->PID List->Engine->Idle.
RAF is Running Airflow table and it's responsible for a lot of 'off throttle' behaviors, so it's very important to drivability.
RAF is Running Airflow table and it's responsible for a lot of 'off throttle' behaviors, so it's very important to drivability.
Thread Starter
Joined: Sep 2003
Posts: 1,199
Likes: 0
From: Richmond, VA
[QUOTE=RedHardSupra]IAC Position and IAC Desired Position is what you want, you can find it under Insert->PID List->Engine->Idle.[QUOTE]
I tried that and when I went to upload the new config, the table never changed, did I miss something?? Also I just looked at and I didn't find the RAF table, I looked under idle & fuel cutout and airflow and couldn't find it, is it labled Running Airflow?? Also I just looked at something and my IAC reset park position is 310, is that normal?? That seems like a pretty big number for the IAC's.
I tried that and when I went to upload the new config, the table never changed, did I miss something?? Also I just looked at and I didn't find the RAF table, I looked under idle & fuel cutout and airflow and couldn't find it, is it labled Running Airflow?? Also I just looked at something and my IAC reset park position is 310, is that normal?? That seems like a pretty big number for the IAC's.
Trending Topics
Thread Starter
Joined: Sep 2003
Posts: 1,199
Likes: 0
From: Richmond, VA
Originally Posted by RedHardSupra
IAC Position and IAC Desired Position is what you want, you can find it under Insert->PID List->Engine->Idle.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo Thread Starter
Joined: Sep 2003
Posts: 1,199
Likes: 0
From: Richmond, VA
well I figured out my table display problem and where the RAF table is. I have another question, does it make sense for this problem to start out of nowhere and it still being a tune related problem?? What I am saying is I have looked at all the over obvious like a vacuum leak and throttle linkage and have found no problems with them, I believing that this is tune related, but I can't understand how this would happen all of a sudden when I haven't touched the tune in 4 months, which makes me think I missed something when looking for vacuum leaks. Anyone care to comment??
Thread Starter
Joined: Sep 2003
Posts: 1,199
Likes: 0
From: Richmond, VA
anyone heard of a cracked air lid causing a vacuum leak?? Uploaded numerous tunes in it and nothing's fixed it. One minute you start the car up and it idles fine, next minute, it idles high 
Thread Starter
Joined: Sep 2003
Posts: 1,199
Likes: 0
From: Richmond, VA
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.
