You could keep trying, but I would always revert back to that if what you tried doesn?t work. It?ll leave you that much less frustrated when you aren?t tuning and your car isn?t idle hunting. Definitely don?t give up on it, especially if it seems like you are getting close.
keep the cams at max separation and maintain the idle advance closer to the 20's. should tone the exhaust down and run somewhat smoother to prevent issues with neighbors.
the cam tables for catalyst heating have lots of overlap to allow the more of the heat post burn to exit into the cat. remove some of this overlap to prevent excessive noise.
2000 Ford Mustang - Top Sportsman
'Originally Posted by cobaltssoverbooster
By max separation do you mean 10 for intake and -6 for exhaust, or parked?
As far as idle timing, I've played with the main timing tables and OS tables and can't seem to get it to come up to 20. I've added about 5 degrees of advance to the ECT spark table which brought it up a little but I can't seem to get rid of the negative timing at initial startup which causes the idle fluctuations. I posted my tune a few replies back, perhaps you can give me some insight on what numbers I need in the idle spark area to achieve 20 degrees.
Thanks for the help fellas!
set desired timing and manipulate everything that models airflow and torque output to bring the value to the desired target.
there is no here is the answer. with ignition you put what you want in it and modify everything else to get a result that matches.
2000 Ford Mustang - Top Sportsman
I?ve set the cams to be parked during idle on warmup. I?ve also modified the main warm/cold warmup tables to keep the cams parked in the idle area. I bumped timing up on the main spark/OS tables in the idle area as well. I?ll have to wait until it?s 50 degrees or below to see if it?s helped anything. I don?t understand why if the starting coolant temp is above 50 it starts and idles just fine. The closer the temp gets to 50 degrees, the worse the initial stutter/idle hunt is. How can a couple degrees in temp affect the idle that much?
depends on what is being triggered that at that coolant temp. it could be something sensor related or it could be a table that needs to be worked on which is aggressively adding or removing something at that temperature.
2000 Ford Mustang - Top Sportsman
Well fellas, a quick update. I finally had some time to tinker around and I think I've got it licked. Set the timing to the same values in the idle area, raised OS, and lowered dals a bit in the idle area. I'm getting a consistent 18-21 degrees of timing at idle and it started like a champ in 20 degree weather this morning. I'm getting some oscillations at idle which I'm pretty sure are due to fuel trims being off a bit. Thanks for the help and encouragement!
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Last edited by Jaizero; 11-10-2017 at 12:59 PM.
GMtech cam tables attached
Last edited by 2000Firehawk; 11-10-2017 at 07:17 PM.
2009 HHR SS automatic--- 350 HP - 450' LBS TORQUE,http://www.youtube.com/watch?v=mDZgoSN8Gk0
Mostly stock - K&N air intake, TTech engine mount, 2nd cat 'cored', E47.5 tune, Lighter - wheels/tires/rotors.
13.0's @ 110MPH, street tires, 12.28 @ 112.67 best on slicks, 1.7s 60' ETs
So another update. I'm seriously about to start this car on fire. I cannot for the life of me get it to quit surging and hunting after I get the idle up to around 20 degrees. It'll start fine, but after the coolant temp gets to about 100 degrees, it starts revving up and down hunting. I've adjusted DALs and optimum torque up, down, left, right every which way and I cannot get it to stop. This is so f*&*%ing annoying.
It's been over a year since I sold my Sky so my help may not be as good as what you'll get from the others here but after peeking at your tune, I would suggest that you review the Gm Tech tunes posted above and review his cam tables. See how he's got 10 degrees in the Main (Warm) and Main (Cold) tables for intake in the low load regions and -6 degrees in the Main tables for exhaust in the low load regions? Try that on your cam tables and copy/paste the Main (Warm) table into the Main (Cold) AND into the Main (Warm) Main (Cold) tables under Catalyst Heating so that all of the Main tables are the same for intake with 10 degrees in the low load regions. Then do the exhaust tables making all 4 Mains the same as well with -6 degrees in the low load regions and see if that helps with your hunting issue.
Thanks a lot for the input. Just to clarify, The main warm and cold should be the same for the base angle tables AND the catalyst heating tables? Essentially, all the intake main and warm tables should be the same and all the exhaust main and warm tables should be the same?
Yes
I gave this a try, and there is certainly a marked improvement! I have the timing set for 20 degrees in the main spark tables in the idle area, and OS set for about 42 or 43 and I'm seeing about 16-18 degrees of advance at idle.
Not sure if this is normal, but I still see the cams flickering at idle even though I have them parked. I still need to work on keeping the timing from dipping negative on a cold start to prevent the stumble, but there was almost no hunting at idle.
Glad to hear it helped!
Never mind, it's still hunting. It seems to start fine, but gets worse as it warms up. As it's warming and idling down, it hits about 1000rpm then that's when it starts hunting the worst. I just want this damn car to start properly in cold weather.
Are you running E47?
Yes, however, it has done this with regular gas or E85. The real problem I'm trying to fix is when it gets cold and I start the car in the morning, it starts up just fine but it wants to idle down too far and bog out and die. It never dies, it usually figures things out and starts to idle normally. It only does this when it's below like 40F. Above 40F and it starts and idles great.
I'm just tossing out suggestions here that won't hurt to try and if you've tried them already, it can't hurt to try again with the changed cam tables.
Try lowering your DAL table in the 20% and 25% columns to 35 in the 20% column from 600rpm to 1500rpm and to 45 in the 25% column at the same 600-1500rpm and then smooth those with the surrounding cells. Maybe the smaller jump there will keep it happy.
Also lower your Target Idle Speeds in the -22* to 86* range back to 950rpm.
Well, I gave your suggestion a try and I've seen some strange results. I've attached the tune as it sits, and a log of startup and idle. In the log you can see it hunting, I'm not sure how to fix that. Once the car warms up past 120-140F it seems to smooth out with only a few bumps here and there. The cold weather is causing this because it never happens when it's warm out. I'll keep knocking the DALs down to see if it smooths out.
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