idle tuning, ls1 edit. Sorry for asking, i searched though :)
03-09-2007, 09:02 PM
#1
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idle tuning, ls1 edit. Sorry for asking, i searched though :) I just installed my new engine, 347 CI 232/236 cam. It really isnt being to nice getting it to startup and I cant get it to idle on its own. It seems to be running pretty rough right now. Where should i start out in LS1 edit to get this idle tuning down? I have a NW 90mm TB and it doesnt have a setscrew from what I saw so I guess i have to drill the hole out more in the TB blade.
Can anyone give me a quick and easy to understand rundown on what i want to do? I appreciate any help i can get.
Oh yeah I didnt hook my MAF back up either, I replaced it with a new hose coupling thaty goes straight from the lid to the TB.
What confuses me is that I thought airflow at idle would increase with the cam but from what I hjave been reading it sounds to me that airflow at idle should go down. Which is right?
Please bear with me, idle tuning the cam is like learning tuning all over again for me.
Can anyone give me a quick and easy to understand rundown on what i want to do? I appreciate any help i can get.
Oh yeah I didnt hook my MAF back up either, I replaced it with a new hose coupling thaty goes straight from the lid to the TB.
What confuses me is that I thought airflow at idle would increase with the cam but from what I hjave been reading it sounds to me that airflow at idle should go down. Which is right?
Please bear with me, idle tuning the cam is like learning tuning all over again for me.
Last edited by brad8266; 03-09-2007 at 09:18 PM.
03-09-2007, 09:22 PM
#2
nogo put together a pretty good idle tuning writeup together a couple of years ago that he posted...I'll see if I can't dig it up...its actually a very good writup for starting out.
Theres alot of different angles you'll need to hit though..I will say bi-directional controls make it much easier.
Theres alot of different angles you'll need to hit though..I will say bi-directional controls make it much easier.
03-09-2007, 09:25 PM
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Originally Posted by foff667
nogo put together a pretty good idle tuning writeup together a couple of years ago that he posted...I'll see if I can't dig it up...its actually a very good writup for starting out.
Theres alot of different angles you'll need to hit though..I will say bi-directional controls make it much easier.
Theres alot of different angles you'll need to hit though..I will say bi-directional controls make it much easier.
03-09-2007, 09:29 PM
#4
originally posted by NoGo on ls1tech.com
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.
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.
03-09-2007, 09:33 PM
#5
You can also dial in your base running airflow tables using several different methods
1. some use desired idle airflow PID & just plug that in
2. some use (LTIT+STIT)/2 and add that to their table
3. some just use STIT & add that to their table.
I don't think theres a proven "right" or "wrong" way about it, but then again idle isnt always necessarily cut & dry especially when the cams are larger. Sometimes just a little fuel tweaking can make a huge difference...sometimes just a timing change for the idle tables can make a huge difference...these are just basic guidelines.
1. some use desired idle airflow PID & just plug that in
2. some use (LTIT+STIT)/2 and add that to their table
3. some just use STIT & add that to their table.
I don't think theres a proven "right" or "wrong" way about it, but then again idle isnt always necessarily cut & dry especially when the cams are larger. Sometimes just a little fuel tweaking can make a huge difference...sometimes just a timing change for the idle tables can make a huge difference...these are just basic guidelines.
03-09-2007, 09:54 PM
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Thanks guys. Hopefully I can get it running Ok tommorow. Too bad my PS pulley and pump broke today, that is keeping me from doing any real driving. maybe Ill go get a short *** belt tommorow and run with no PS.
i also think my plugs fouled from when i first started the car up after the install, i still had the stock injector size in the tune.
i also think my plugs fouled from when i first started the car up after the install, i still had the stock injector size in the tune.
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03-10-2007, 03:41 PM
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I flashd a new tune with the items that are listed above. I also pulled the plugs before i started it and they were very fouled from when I started it yeaterday with the stock IFR table in there. Anyway with the IFR scaled and idle parameters changed it fired right up and then I used the setscrew a little bit to get it to hold a decent idle around 900-950.
03-10-2007, 04:44 PM
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Originally Posted by foff667
cool deal 
What should i do to the cranking tables? It has a hard time starting sometime. I have to keep it cranking a while.
03-10-2007, 05:35 PM
#13
Originally Posted by brad8266
I guess having 1/4 tank of some 4 month old gas isnt helping any either.
yeah probably not to much, i wouldn't go crazy trying to dial anything in till you get some fresh gas in there. It's surging cause you probably have way to much fuel in the lower end of your ve table
03-10-2007, 06:41 PM
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Originally Posted by nikon1999
yeah probably not to much, i wouldn't go crazy trying to dial anything in till you get some fresh gas in there. It's surging cause you probably have way to much fuel in the lower end of your ve table
My PS pulley broke into 5 pieces and took the pump resovior with it so I cant drive it anywhere till I get it replaced since my water pump wont turn now without the belt.
03-10-2007, 07:33 PM
#16
Originally Posted by foff667
originally posted by NoGo on ls1tech.com
Here are some things you can try.
.....
Fuel --> Main VE Table: Multiply column 400 rpm by 60. Multiply column 800 by 80. Multiply column 1200 by 90.
...........
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.
..........
Here are some things you can try.
.....
Fuel --> Main VE Table: Multiply column 400 rpm by 60. Multiply column 800 by 80. Multiply column 1200 by 90.
...........
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.
..........
For anyone who is new and reading this, 60, 80, and 90 are percents (%)! Do NOT multiply your table by these numbers. You want to use 0.60, 0.80, and 0.90.
In the second bit quoted, not that total reduction from stock should be 15%-ish at that point
Last edited by Frost; 03-10-2007 at 07:38 PM.
03-10-2007, 07:37 PM
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Originally Posted by Frost
???
For anyone who is new and reading this, 60, 80, and 90 are percents (%)! Do NOT multiply your table by these numbers. You want 0.60, 0.80, and 0.90.
For anyone who is new and reading this, 60, 80, and 90 are percents (%)! Do NOT multiply your table by these numbers. You want 0.60, 0.80, and 0.90.
I hope nobody tried to actually multiply by 60, lol. 
03-12-2007, 06:14 AM
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Originally Posted by pkincy
The belt that will fit all your accessory pulleys without the ps pulley is for a late 80's 7.4 L GM diesel.
Don't ask how I know.
Perry
Don't ask how I know.
Perry
Thanks man, wish you would have been here saturday to tell me that, lol. Im picking up a new PS pulley today from the stealership.