how to properly tune Idle on any cammed car??
04-08-2005, 06:21 PM
#1
how to properly tune Idle on any cammed car?? anybody have a nice write up on getting a car to idle properly after a cam??
I keep seeing little posts about idle issues...but I see no Tuning documents for the masses to use...unless I am looking in the wrong spots possibly...
what stuff to edit or change and how to change it...and when it is actually the real time to drill the TB...stuff like that would be nice
I keep seeing little posts about idle issues...but I see no Tuning documents for the masses to use...unless I am looking in the wrong spots possibly...
what stuff to edit or change and how to change it...and when it is actually the real time to drill the TB...stuff like that would be nice
04-09-2005, 10:55 AM
#2
12 Second Club
iTrader: (13)
Join Date: Nov 2004
Location: 707
Posts: 453
Likes: 0
Received 0 Likes
on
0 Posts
Its funny, this is the most basic issue that needs addressed after a cam swap and yet all these tuners and no answer. Whats up? Come on fellas. Someone needs to do a write up.
04-09-2005, 01:46 PM
#4
TECH Addict
Join Date: Jun 2002
Location: Las Vegas, NV
Posts: 2,428
Likes: 0
Received 0 Likes
on
0 Posts
In my best Orange County accent, Money talks, bullshit walks. 
Seriously though, the info is on the site, you just need to keep searching. I wish I could help, but I'm having minor idle issues myself, but I'll figure it out eventually. A good start is to multiply VE cells, 1200rpms and under, by 60%, 80%, and 90%. That should clear up most of the problems, it did for me. I recently purchased an LM-1 which I'm hoping will help me to finish tweaking the idle.
Good luck man!!
Seriously though, the info is on the site, you just need to keep searching. I wish I could help, but I'm having minor idle issues myself, but I'll figure it out eventually. A good start is to multiply VE cells, 1200rpms and under, by 60%, 80%, and 90%. That should clear up most of the problems, it did for me. I recently purchased an LM-1 which I'm hoping will help me to finish tweaking the idle.
Good luck man!!
04-09-2005, 02:24 PM
#5
TECH Enthusiast
Join Date: Jun 2004
Location: Fredericksburg, VA
Posts: 576
Likes: 0
Received 0 Likes
on
0 Posts
Start with leaning out the VE table like was stated above. Also raise the timing in the same area. 22* is a good starting point. This should make a world of difference. Also, there is a thread on the HPTuners forum titled "How to get a heads/cam car to idle" that goes more in depth.
Trending Topics
04-10-2005, 12:05 AM
#9
Little cam...little change. Big cam.....big change. Add in other mods...90mm intake, ported heads, bumped CR etc. etc. the combos are infinite and so are the neccesary adjustments. There is no standard,easy fix for all combos.
04-10-2005, 08:38 AM
#12
I tired that spreadsheet in the sticky to calculate a new RAF and the code in the calculation just seems to keep working and never calculates a new RAF table. It just keeps working till I press escape.
Anyone else have problems with this spreadsheet? Or anyone have it work?
I logged only what it said to log and then plugged it in to the data section. Plugged in my current RAF numbers and pressed "calculated new RAF". Then it just keeps working and never finishes!
Anyone else have problems with this spreadsheet? Or anyone have it work?
I logged only what it said to log and then plugged it in to the data section. Plugged in my current RAF numbers and pressed "calculated new RAF". Then it just keeps working and never finishes!
04-10-2005, 10:05 AM
#13
From another thread.... something I'll be trying today...
Originally Posted by NoGo
I don't want to step on anybody's toes here, but you will be able to get it to idle without drilling your TB. I actually prefer not to drill the TB. We tune 240+ cams without drilling the TB.
Here are some things you can try.
Idle Limiters --> Idle Speed: 950
Idle Limiters --> IAC Park Position: Raise all points from 40C and up to 21
Idle Limiters --> Idle Air In Gear: All points 60C and up to 8.6
Fuel --> Main VE Table: Multiply column 400 rpm by 60. Multiply column 800 by 80. Multiply column 1200 by 90.
Ignition --> High Octane Table: Add 2 deg to all points 400 to 1000 RPM, .08 to .32 g/sec
Once done with this program, start the car and check for surging. If the car surges, unplug the IAC and see if the surging stops. If the surging stops follow below.
Idle Limiters --> Idle Air in Gear --> All points above 60C to 9.2
Take the car for a drive and check your idle. If the car goes on cruise control reduce the Idle Air in Gear Table .2 (further if necessary). If the idle holds at 2000 RPM for extended periods of time reduce the P/N Airflow Decay table for all points above 10 MPH by 5% (multiply by 95) until this stops. Be vary careful on this table.
If car keeps surging with the IAC unplugged two more things to try.
Multiply Main VE table by another 95% (total reduction of 85%). Repeat until the surging goes away, or until the car begins to hesitate when you take off.
High Octane Ignition Table. Reduce timing for all points 400 to 1000 RPM, .08 to .32 g/sec by 2. Repeat, but don't reduce it any more than 6 degrees.
If your car still doesn't idle after this, then you have other problems, and should start looking elsewhere.
Good Luck
Here are some things you can try.
Idle Limiters --> Idle Speed: 950
Idle Limiters --> IAC Park Position: Raise all points from 40C and up to 21
Idle Limiters --> Idle Air In Gear: All points 60C and up to 8.6
Fuel --> Main VE Table: Multiply column 400 rpm by 60. Multiply column 800 by 80. Multiply column 1200 by 90.
Ignition --> High Octane Table: Add 2 deg to all points 400 to 1000 RPM, .08 to .32 g/sec
Once done with this program, start the car and check for surging. If the car surges, unplug the IAC and see if the surging stops. If the surging stops follow below.
Idle Limiters --> Idle Air in Gear --> All points above 60C to 9.2
Take the car for a drive and check your idle. If the car goes on cruise control reduce the Idle Air in Gear Table .2 (further if necessary). If the idle holds at 2000 RPM for extended periods of time reduce the P/N Airflow Decay table for all points above 10 MPH by 5% (multiply by 95) until this stops. Be vary careful on this table.
If car keeps surging with the IAC unplugged two more things to try.
Multiply Main VE table by another 95% (total reduction of 85%). Repeat until the surging goes away, or until the car begins to hesitate when you take off.
High Octane Ignition Table. Reduce timing for all points 400 to 1000 RPM, .08 to .32 g/sec by 2. Repeat, but don't reduce it any more than 6 degrees.
If your car still doesn't idle after this, then you have other problems, and should start looking elsewhere.
Good Luck
04-10-2005, 10:25 PM
#14
The first step is to make sure your engine is getting enough air without relying on the IAC. To do that you have to either open the throttle blade more or drill the throttle body hole. That will solve most of your problems. I will probably do a small write up soon but i've gotta try out my IAC vs effective are theory first.
04-11-2005, 05:12 AM
#15
I tried messing with the desired IAC vs. effective area table and shifting to the right did not affect my IAC counts at all. Not quite sure what it did! Car did not idle though. Maybe I need to shift it to the left.
WHen I shifted it to the right. The car acted like i had backed off my set screw a bunch so the throttle blade closed. Car would not idle by itself(i shifted all the numbers to the right 4 cells)
WHen I shifted it to the right. The car acted like i had backed off my set screw a bunch so the throttle blade closed. Car would not idle by itself(i shifted all the numbers to the right 4 cells)
04-11-2005, 07:16 AM
#16
11 Second Club
iTrader: (2)
Join Date: Dec 2003
Location: Montgomery, AL.
Posts: 535
Likes: 0
Received 0 Likes
on
0 Posts
I found a wealth of info on this link that is listed as a sticky above. http://www.transamws6.net/HPTuners/ls1tuninginfo.doc I am sure ya'll have seen it but I thought that I would list it just in case someone overlooked it. Cheers !!!
Jim C.
Jim C.
04-11-2005, 10:25 AM
#17
Originally Posted by 99whitews6
I tired that spreadsheet in the sticky to calculate a new RAF and the code in the calculation just seems to keep working and never calculates a new RAF table. It just keeps working till I press escape.
Anyone else have problems with this spreadsheet? Or anyone have it work?
I logged only what it said to log and then plugged it in to the data section. Plugged in my current RAF numbers and pressed "calculated new RAF". Then it just keeps working and never finishes!
Anyone else have problems with this spreadsheet? Or anyone have it work?
I logged only what it said to log and then plugged it in to the data section. Plugged in my current RAF numbers and pressed "calculated new RAF". Then it just keeps working and never finishes!
I used version 1.33 of the referenced spreadsheet very successfully. I have an '03 Z06 if that makes a difference in the PCM.
04-11-2005, 10:42 AM
#18
Originally Posted by 99whitews6
I tried messing with the desired IAC vs. effective area table and shifting to the right did not affect my IAC counts at all. Not quite sure what it did! Car did not idle though. Maybe I need to shift it to the left.
WHen I shifted it to the right. The car acted like i had backed off my set screw a bunch so the throttle blade closed. Car would not idle by itself(i shifted all the numbers to the right 4 cells)
WHen I shifted it to the right. The car acted like i had backed off my set screw a bunch so the throttle blade closed. Car would not idle by itself(i shifted all the numbers to the right 4 cells)