2002 Lq4 tuning idle too high.

[eric camaro]

Hey Guys Newbie over here, been doing a lot of reading, and I finally got the motor to idle, not the greatest. but it's running.
My concern now is idle too high, and my LTFT bank 1 is at -13, LTFT bank 2 is at -9. It's so rich that I am wearing the smell with me all day.
here are the mod on the LQ4 engine. Please take a look of my file, if you guys can rewrite my file that would be great. also if you guys can suggest of any changes on the timing to help the motor that would be great too.
-L92 heads.
-LS3 manifold.
-ls1 xr275hr-12 camshaft (275/277 Advertised Duration, 222/224 Duration @ .050 inch, .566 inch/.568 inch Lift, 112 Lobe Separation)
-long tube header
-no cats
-90mm elderbroke throttle body
-stock maf

Thank you in advance

Eric

[reactor2]

Hey Guys Newbie over here, been doing a lot of reading, and I finally got the motor to idle, not the greatest. but it's running.
My concern now is idle too high, and my LTFT bank 1 is at -13, LTFT bank 2 is at -9. It's so rich that I am wearing the smell with me all day.
here are the mod on the LQ4 engine. Please take a look of my file, if you guys can rewrite my file that would be great. also if you guys can suggest of any changes on the timing to help the motor that would be great too.
-L92 heads.
-LS3 manifold.
-ls1 xr275hr-12 camshaft (275/277 Advertised Duration, 222/224 Duration @ .050 inch, .566 inch/.568 inch Lift, 112 Lobe Separation)
-long tube header
-no cats
-90mm elderbroke throttle body
-stock maf

Thank you in advance

Eric

The fact that the LTFTs are high doesn't necessarily mean its burning rich. Those values are basically the amount of fuel required to bring the AFR to stoich. Basically your current tune is expecting less air then it is receiving and, thus, the O2s are telling it to add more fuel. I'm running a similar cam (228/232 .571/.573 112) that has a fair amount of overlap and after a fair amount of tuning (I'm not an expert) I have similar LTFTs (in P/N) as you and my WB O2 tells me I'm at stoich...and you can smell the unburned fuel as well.

Idle timing w/ cam
1) Make sure injectors are scaled correctly (need manufacturer data for this)
2) dial in the MAF and VE
3) increase spark advance several degrees in idle range
4) reduce spark overspeed and underspeed a few degrees

Your cam should be able to idle 700-800rpm range.

With all that being said, my car still doesn't idle as well as I want it to. In gear (I have an auto) it idles well w/ low LTFTs but in P/N it can still push the LTFTs up there. The biggest problem I have is that after 5 mins or so of idling in P/N it may start to hunt for the idle. It will usually clear itself up after a few swings but after another 5 or so minutes it will do it again. Still haven't found a solution for this behavior.

[Ranger6202]

+1 on what reactor2 said concerning eric's issues. For reactor2's issues of it hunting after a bit i would check out the idle steady state stuff under the dynamic airflow tab. If you can see how much your cam is moving your MAP under idle, take that fluctuation amt., add a little, and then make that your new low delta value. This should keep you in "idle steady state" (maf) and your ltft's shouldn't all the sudden start changing again after awhile from going in between steady state (maf) and not (ve) due to the lo delta value being too small and your cam hitting the lo delta kpa limit. If you can get your VE idle cell value closer to your maf idle value, you should see a smaller swing too, but it will still be switching back and forth due to the lo delta limit, just your ltft's won't swing hardly as much when it does. Or it's something totally different and i just wasted 10 minutes writing that .