Idle Maxxed out after heads/cam install
07-14-2004, 12:18 PM
#1
On The Tree
Thread Starter
iTrader: (25)
Join Date: Nov 2001
Location: NW Houston
Posts: 131
Likes: 0
Received 0 Likes
on
0 Posts
Idle Maxxed out after heads/cam install Just finished installing PP Stage II LS6 heads and a TR 227/230 .569 .576 114 cam. Also changed oil pump, chain, added LS6 intake, new power steering pump, etc.
There are no leaks and everything looks good but when I crank the car up the idle maxes out at about 3500 rpm. This is commanded by the PCM because when I remove the IAC, I can see that the pintle is all the way back, letting in the max air.
What do I need to adjust with LS1Edit to keep the idle from running away?
There are no leaks and everything looks good but when I crank the car up the idle maxes out at about 3500 rpm. This is commanded by the PCM because when I remove the IAC, I can see that the pintle is all the way back, letting in the max air.
What do I need to adjust with LS1Edit to keep the idle from running away?
07-14-2004, 06:19 PM
#5
On The Tree
Thread Starter
iTrader: (25)
Join Date: Nov 2001
Location: NW Houston
Posts: 131
Likes: 0
Received 0 Likes
on
0 Posts
Well the injectors are all down good, all electrical connections are made, the knock sensor wire seems to go under the intake right through the middle of the back. Intake looks flush and even all the way around.
I have noticed something new I haven't before. When I turn car the off.... about 1 or 2 seconds after the motor stops completely, I hear this crazy 'marbles-in-a-can' sound coming _directly_ from the IAC motor. I am guessing it is trying to park itself but maybe it has stripped out the drive?
I have noticed something new I haven't before. When I turn car the off.... about 1 or 2 seconds after the motor stops completely, I hear this crazy 'marbles-in-a-can' sound coming _directly_ from the IAC motor. I am guessing it is trying to park itself but maybe it has stripped out the drive?
07-16-2004, 09:54 PM
#6
On The Tree
Thread Starter
iTrader: (25)
Join Date: Nov 2001
Location: NW Houston
Posts: 131
Likes: 0
Received 0 Likes
on
0 Posts
New IAC fixed the problem. Now I just have to figure out how to keep it from stalling at a stop and cruise control the rest of the time :/ No idle hunt at least.
07-17-2004, 12:00 PM
#7
Originally Posted by RCowan
New IAC fixed the problem. Now I just have to figure out how to keep it from stalling at a stop and cruise control the rest of the time :/ No idle hunt at least.
joel Trending Topics
07-17-2004, 01:26 PM
#8
On The Tree
Thread Starter
iTrader: (25)
Join Date: Nov 2001
Location: NW Houston
Posts: 131
Likes: 0
Received 0 Likes
on
0 Posts
TB hole was previously drilled to 1/4"
Idle park position is 21.00 at all positions 20C and above
Idle Air in Gear
I have tried anything from stock values up to 10.0 from 60C and up and it only seems to affect the situation a little bit.
I increased the timing from 6 to 4 degrees (variable) in the high octane table from 0.08gm to 0.32 gm and from 400 to 800rpm
I reduced the VE 65%, 75%, and 85% on the 400, 800 and 1200 rpm columns. Then later i scaled the whole table 95%
The differences between the changes have been only slight. I tried idles from 850 to 950. 950 of course is more stable but not a whole lot.
Basically the car will cruise control between 1500 and 2000 rpm all the way up to 50mph or so. When I slow down to a stop it will slowly come down until I reach ~1200rpm or 12mph or so and then it will drop to 400 rpm and almost die like somebody flipped a switch. Then it will rise back to idle without hunting. Its like there's a lot of damping in that idle range.
I would think if it needed more idle air it would hunt a lot? Not sure what to do at this point
Idle park position is 21.00 at all positions 20C and above
Idle Air in Gear
I have tried anything from stock values up to 10.0 from 60C and up and it only seems to affect the situation a little bit.
I increased the timing from 6 to 4 degrees (variable) in the high octane table from 0.08gm to 0.32 gm and from 400 to 800rpm
I reduced the VE 65%, 75%, and 85% on the 400, 800 and 1200 rpm columns. Then later i scaled the whole table 95%
The differences between the changes have been only slight. I tried idles from 850 to 950. 950 of course is more stable but not a whole lot.
Basically the car will cruise control between 1500 and 2000 rpm all the way up to 50mph or so. When I slow down to a stop it will slowly come down until I reach ~1200rpm or 12mph or so and then it will drop to 400 rpm and almost die like somebody flipped a switch. Then it will rise back to idle without hunting. Its like there's a lot of damping in that idle range.
I would think if it needed more idle air it would hunt a lot? Not sure what to do at this point
07-17-2004, 02:28 PM
#9
Add 4* timing, both Idle Timing tables, .08 - .32 g/cyl , 1200 RPM and down. Set RAF/Idle Air in Gear to 9.4 56*C and up. Set all "throttle Follower Tables to stock. Pull the PCM fuses for about 2-3 minutes after each flash. Take it out and let it run for awhile- drive it for "learn". If it still cruises then reduce RAF in 0.2 increments - pull the fuses and drive. Once you begin to reduce the cruise substantially then move to the Decay in gear table and start reducing it a little at a time ( say~ 5%).
07-17-2004, 08:08 PM
#11
On The Tree
Thread Starter
iTrader: (25)
Join Date: Nov 2001
Location: NW Houston
Posts: 131
Likes: 0
Received 0 Likes
on
0 Posts
Well, Bink, I had just written your changes into the file and programmed it in. Then I tried to start the car and Bwwraaaap. The starter broke. Broke right on the flange where the shorter bolt goes in. lol 
I guess the extra compression was too much for 5 yr old, 84000 mile starter.
I'm out of the country for a week starting tomorrow, so hopefully a new starter will be at my door when I get back and I can start tuning again.
BTW.. I increased timing 4 degrees on both Base Spark tables and the High Octane table, is that what you meant by 'both tables'--the base spark tables?
I guess the extra compression was too much for 5 yr old, 84000 mile starter.I'm out of the country for a week starting tomorrow, so hopefully a new starter will be at my door when I get back and I can start tuning again.
BTW.. I increased timing 4 degrees on both Base Spark tables and the High Octane table, is that what you meant by 'both tables'--the base spark tables?
07-28-2004, 10:35 PM
#13
TECH Fanatic
Join Date: Mar 2003
Location: La Porte, TX
Posts: 1,839
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by Bink
Add 4* timing, both Idle Timing tables, .08 - .32 g/cyl , 1200 RPM and down. Set RAF/Idle Air in Gear to 9.4 56*C and up. Set all "throttle Follower Tables to stock. Pull the PCM fuses for about 2-3 minutes after each flash. Take it out and let it run for awhile- drive it for "learn". If it still cruises then reduce RAF in 0.2 increments - pull the fuses and drive. Once you begin to reduce the cruise substantially then move to the Decay in gear table and start reducing it a little at a time ( say~ 5%).
Talk about a detailed explanation. I'm having the same exact problem... with my PP stage II Ls6/ G5X-3 combo. It is worse in reverse, than in drive especially during open loop. I have been spending the last couple of days getting all my LTFT's in order, and it actually seems worse now. Will making these changes affect my LTFT's at all? I'm going to give this a shot tomorrow at lunch.
08-02-2004, 10:03 PM
#14
On The Tree
Thread Starter
iTrader: (25)
Join Date: Nov 2001
Location: NW Houston
Posts: 131
Likes: 0
Received 0 Likes
on
0 Posts
Well I got the new starter in and soon discovered that the hole i drilled in the TB way-back-when was too big, sending my IACs to zero when it warmed up and idling like 1200. I got a ported TB to fix that problem It idles fine at 900 but still goes on cruise control and does that thing where when you come to a stop it will hang at 1400rpm or so for a few seconds, until finally dropping to idle. I'm just going to start over and do it a step at a time.
It idles fine at 900 but still goes on cruise control and does that thing where when you come to a stop it will hang at 1400rpm or so for a few seconds, until finally dropping to idle. I'm just going to start over and do it a step at a time. 