infamous hanging idle
#1
Restricted User
Thread Starter
iTrader: (207)
Join Date: Aug 2005
Location: jacksonville, fl.
Posts: 555
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
have a case of the infamous hanging idle. problems/symptoms are as follows.....
only hangs at 10 mph and over. car is running extreamly rich at idle and lower speeds.
not tune related. it has been profesionally tuned (by 2 different tuners) one with efi live / road-runner.
not throwing any codes.
this is the 2nd motor, 4th intake, 3rd t/b, 2nd set of rails/injectors, 4th tps, 3rd map sensor and 3rd iac used to try and find the problem. nothing that i have replaced has seemed to make a difference. problem started after a h/c swap on the first motor.
any ideas or help would be greatly appreciated. thanks!
only hangs at 10 mph and over. car is running extreamly rich at idle and lower speeds.
not tune related. it has been profesionally tuned (by 2 different tuners) one with efi live / road-runner.
not throwing any codes.
this is the 2nd motor, 4th intake, 3rd t/b, 2nd set of rails/injectors, 4th tps, 3rd map sensor and 3rd iac used to try and find the problem. nothing that i have replaced has seemed to make a difference. problem started after a h/c swap on the first motor.
any ideas or help would be greatly appreciated. thanks!
Last edited by WS6nJAX; 02-06-2008 at 10:51 AM.
#2
Banned
iTrader: (10)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
have a case of the infamous hanging idle. problems/symptoms are as follows.....
only hangs at 10 mph and over. car is running extreamly rich at idle and lower speeds.
not tune related. it has been profesionally tuned (by 2 different tuners) one with efi live / road-runner.
not throwing any codes.
this is the 2nd motor, 4th intake, 3rd t/b, 2nd set of rails/injectors, 4th tps, 3rd map sensor and 3rd iac used to try and find the problem. nothing that i have replaced has seemed to make a difference. problem started after a h/c swap on the first motor.
any ideas or help would be greatly appreciated. thanks!
only hangs at 10 mph and over. car is running extreamly rich at idle and lower speeds.
not tune related. it has been profesionally tuned (by 2 different tuners) one with efi live / road-runner.
not throwing any codes.
this is the 2nd motor, 4th intake, 3rd t/b, 2nd set of rails/injectors, 4th tps, 3rd map sensor and 3rd iac used to try and find the problem. nothing that i have replaced has seemed to make a difference. problem started after a h/c swap on the first motor.
any ideas or help would be greatly appreciated. thanks!
What throttle body do you have? Several aftermarket ones are known for this. Also a possible vac leak...If not a vacum leak then it probably is tune related.
#4
TECH Enthusiast
iTrader: (6)
Join Date: Apr 2007
Location: Nor Cal
Posts: 540
Likes: 0
Received 0 Likes
on
0 Posts
![](https://ls1tech.com/forums/images/ranks/ls1tech10year.png)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
have a case of the infamous hanging idle. problems/symptoms are as follows.....
only hangs at 10 mph and over. car is running extreamly rich at idle and lower speeds.
not tune related. it has been profesionally tuned (by 2 different tuners) one with efi live / road-runner.
not throwing any codes.
this is the 2nd motor, 4th intake, 3rd t/b, 2nd set of rails/injectors, 4th tps, 3rd map sensor and 3rd iac used to try and find the problem. nothing that i have replaced has seemed to make a difference. problem started after a h/c swap on the first motor.
any ideas or help would be greatly appreciated. thanks!
only hangs at 10 mph and over. car is running extreamly rich at idle and lower speeds.
not tune related. it has been profesionally tuned (by 2 different tuners) one with efi live / road-runner.
not throwing any codes.
this is the 2nd motor, 4th intake, 3rd t/b, 2nd set of rails/injectors, 4th tps, 3rd map sensor and 3rd iac used to try and find the problem. nothing that i have replaced has seemed to make a difference. problem started after a h/c swap on the first motor.
any ideas or help would be greatly appreciated. thanks!
#6
Restricted User
Thread Starter
iTrader: (207)
Join Date: Aug 2005
Location: jacksonville, fl.
Posts: 555
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
i had a bbk on the first set-up. i currently have a ptm with my 90/90, but i recently tried putting a stock intake, t/b, rails and injectors back on and the problems still were there. it has all the characteristics of of a vac leak, but the problem has been persistant with all the different pieces and there is no leak.
none of the blades were drilled.
none of the blades were drilled.
#7
TECH Enthusiast
iTrader: (6)
Join Date: Apr 2007
Location: Nor Cal
Posts: 540
Likes: 0
Received 0 Likes
on
0 Posts
![](https://ls1tech.com/forums/images/ranks/ls1tech10year.png)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
If the car was tuned with the BBk then you went to a Fast 90 and now back to stock that is alot of big changes to the way the engine is gonna breath so i am sure ur tune is pretty far off now.
Trending Topics
#8
Restricted User
Thread Starter
iTrader: (207)
Join Date: Aug 2005
Location: jacksonville, fl.
Posts: 555
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
idle hangs around 1600-1800 rpms.
parts were replace to to eliminate possible culprits. the first build was a simple h/c swap and i put a weiand intake on it. the problem seemed to be vac related so i swapped to a ported ls2 intake i picked up from a well know tuner here in florida. even after being tuned the problems were still there.
i had a high miles on the motor, i had a chance to pick-up a newer ls6 short-block, so i went with a complete different set-up (heads, cam, fast intake, everything.....) after the swap the problem was still there. took it have it retuned and the problems still wont go away. even when another tuner used the road-runner the problems still were there.
parts were replace to to eliminate possible culprits. the first build was a simple h/c swap and i put a weiand intake on it. the problem seemed to be vac related so i swapped to a ported ls2 intake i picked up from a well know tuner here in florida. even after being tuned the problems were still there.
i had a high miles on the motor, i had a chance to pick-up a newer ls6 short-block, so i went with a complete different set-up (heads, cam, fast intake, everything.....) after the swap the problem was still there. took it have it retuned and the problems still wont go away. even when another tuner used the road-runner the problems still were there.
#10
TECH Resident
iTrader: (2)
Join Date: Sep 2004
Location: Cleveland, Oh
Posts: 810
Likes: 0
Received 0 Likes
on
0 Posts
![](https://ls1tech.com/forums/images/ranks/ls1tech10year.png)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Sorry but these two statements don't go together. Something is off. Did the tuners remap the VE table? Are you running a MAF? if so did they remap the MAF? Are you runing O2's? Are they functioning properly? Lotsa questions. Start from step 1 on a retune and I bet you'll get it fixed.
#11
TECH Fanatic
Join Date: Feb 2004
Location: Lexington, KY
Posts: 1,259
Likes: 0
Received 0 Likes
on
0 Posts
![](https://ls1tech.com/forums/images/ranks/ls1tech10year.png)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Just because it's been tuned and retuned doesn't mean it's not tune related. If you had to adjust the throttle stop to give it more airflow, did the tuner adjust for this in the "IAC Effective Area" table (EFI Live)? If not it will definately hang just like you describe. There is also an adjustment for moving the throttle stop that has to do with the TPS sensor but I can't remember what it is off the top of my head. And was it dyno tuned only or did they also spend a fair amount of time tuning for driveability?
#12
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
I know you said it had been tuned but it sounds like a tuning issue. I also think it might be a leak. You said you changed a bunch of parts including the manifold. Are you using the same seals? Check and make sure it is sealing correctly.
#13
Restricted User
Thread Starter
iTrader: (207)
Join Date: Aug 2005
Location: jacksonville, fl.
Posts: 555
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
i have had a good friend who has his own shop and is an excellent tuner try with efi live and road-runner. i have also taken it to 2 of the better/well known tuners here in florida and the issues still exhist. with the first set-up i even took it to the the shop that the guy was tuning at and even they said there was no leak. i have used different seals with each intake. the ls2 and fast both had new seals.
#14
Banned
iTrader: (10)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
i have had a good friend who has his own shop and is an excellent tuner try with efi live and road-runner. i have also taken it to 2 of the better/well known tuners here in florida and the issues still exhist. with the first set-up i even took it to the the shop that the guy was tuning at and even they said there was no leak. i have used different seals with each intake. the ls2 and fast both had new seals.
If you take a day & drive down & we can't figure it out I won't charge you. You will need to make an appoinment though to make sure we can do it the day you come.
#16
TECH Apprentice
iTrader: (8)
Join Date: Dec 2005
Location: Morris, IL
Posts: 395
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Same here.... Mine started after the cam install. It drives me crazy, especially when I'm trying to keep the car quiet in town or around cops. I have learned to live with it as it's probably in the tune or just the sensors not responding to the cam. Mine idles down after about 6 or 7 seconds at a stop which tells me it's not a vacuum leak
#17
Restricted User
Thread Starter
iTrader: (207)
Join Date: Aug 2005
Location: jacksonville, fl.
Posts: 555
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Same here.... Mine started after the cam install. It drives me crazy, especially when I'm trying to keep the car quiet in town or around cops. I have learned to live with it as it's probably in the tune or just the sensors not responding to the cam. Mine idles down after about 6 or 7 seconds at a stop which tells me it's not a vacuum leak
#19
TECH Fanatic
iTrader: (17)
Join Date: Nov 2001
Location: SPRING, TX
Posts: 1,387
Likes: 0
Received 0 Likes
on
0 Posts
![](https://ls1tech.com/forums/images/ranks/ls1tech10year.png)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
someone needs to find the solution to this. Mine hangs bad. Around 1600-1800rpm with a/c off and 2100rpm with a/c on. I hate it. Even when the car is warmed up, it will stay the same all day long unless I come to a stop for at least like 30 seconds after it's warmed up. It will idle down once I make a full stop and if I wait 30 seconds, then when I start driving again, when I depress the clutch, the idle drops down to where I want it but if the rpms were too high or I'm stopping really quick, it will surge and die sometimes. Of course, once it dies, it's right back to hanging again unless I sit at a stop for 30 seconds. I don't get it!!!
-Chris
-Chris