my setup is a ls3 stock heads vengeance racing kaotic cam holley highram intake 102 throttle body lsa injectors th350 trans. my ecm is a 411 stock computer running a olsd tune. my idle is timming is not acting right and neither is my iac I believe. seems fine when first start the car after I give it throttle it starts acting up. here is my tune and a recent scan
Have you tried lowering the spark correction at idle, lower it way down from -14 and +14 to something like +/-5 so it can't swing the time so much.
If the wideband is right, it looks way lean at idle too. Way up in the 16-18 range. Also remove the 1 bar MAP channel, it can mess with your graphs/charts if you log the 1 bar and 3 bar channel together.
2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.
If you don't post your tune and logs when you have questions you aren't helping yourself.
What about changing the scaler for the 102mm ?
1997 30th SS. Torqhead 24x, TFS heads, 223/235 cam, 4l80e, S60 D1SC 14psi
both of u need to be a little more specific on your posts do u mean overspeed /underspeed for idle timming? have no idle what to change for 102mm throttle body inform me please
yes the over/under spark correction is what 5F is talking about. Fueling plays a big part of idle quality so he also mentions your wideband reading because having this value match commanded is a big deal at idle.
the scalar is a throttle blade area value. if you havent changed it to resemble your large bore throttle body then you will need to change it to match what you installed.
there is a good chance that your new throttle body is going to have different IAC port flow than stock application which means you may have to calibrate the IAC airflow rates. sometimes a new throttle body also changes the base running airflow as well. all of it adds up to good idle control.
2000 Ford Mustang - Top Sportsman
i have changed the iac steps vs effective area. also iac park position airflow. I believe my issue is that first starting the car seams to idle ok after I give the car throttle it does not want t return to adaptive idle,it stays at a set timming value that is set in my main timming table I posted the scan so people can see what is going on. I know it is running lean now that I know how to fix
my buddys ls1 is running ls9 injectors with a 102 intake/tb/large cam which correct me if im wrong are the same as the lsa. im using a speedsheet for a conversion for ls9 gen 4 to gen 3 data with good luck and it uses some different injector data than what you have but has worked well. ill post it for you to take a peak. i also have his car idling well and i didnt mess with the iac steps. i did adjust iac airflow and braf along with some of adaptive idle and throttle cracker
couple things
0 out the stall savor
in gear idle air should have more airflow than p/n
Attachment 87643
Last edited by TCSS07; 03-10-2019 at 10:09 AM.
the car has a th350 trans ecm has no idea if it in park or in gear. both of my stall savors have matching values
I saw that about stall savor. I was saying to 0 them out. Sometimes it can screw with idle and like others said make sure fueling is spot on or youll just be chasing your tail
your going to want to get the iac counts around the 60-80 range at hot idle
heres a wirte up about idle tuning
https://forum.hptuners.com/showthrea...e-(w-pictures)
Last edited by TCSS07; 03-10-2019 at 12:53 PM.
when you run the th350 you can wire in a pressure switch into the pn circuit for table switching just an fyi.
when i start one of these installs i get it running and set the idle speed with the throttle blade. i adjust the tps voltage to still allow the idle circuit to enable but i play a game where i adjust the throttle blade and tps position until i get the iac counts down to the 40-60 range. gives me a good start.
i disable the adaptive idle airflow settings and calibrate the braf using desired airflow values. re-enable the idle airflow settings and adjust the port iac port flow to make it accurate for the installed device.
all of this while i keep the ve table within +-3% of target stoich afr at idle.
stall saver, over/under idle advance controls, and main idle advance play a roll as well and i set those up along the way as they become issues. I do pre-populate them with settings i know before hand so i do have a decent starting point.
i recommend setting the idle speed to around 800-850 for most applications and i adjust the fuel injector normal table to around 5.9-6.2 at 140*f and above to help clean the idle afr up a tad.
this usually gets me close. maybe some of it can help you out too.
2000 Ford Mustang - Top Sportsman
this is the latest scan and tune idle is getting way better. what u guys think?
im not sure I feel comfortable changing the injector normal table without understanding what the table actually does. can someone explain?
The injection timing changes when the injector starts and ends it cycle. The ls1 sprays the back of the hot intake valve which evaporates the fuel helping in the aid of creating a better fuel mixture
Cams especially larger cams with overlap move the valve events to where typical ls injection is no longer valid.
Cams with lots of overlap will push some of the unburnt fuel out of the exhaust valve before it closes. This can cause the raw fuel smell inaccurate sensor readings and soe low rpm driveability issues.
The idea of stopping this with cams with overlap is to delay the injection timing to start injection after the exhaust valve closes.
Theres more to it i assume but thats simplified.
1997 30th SS. Torqhead 24x, TFS heads, 223/235 cam, 4l80e, S60 D1SC 14psi
that makes sense thank u. typically does it make afr richer or leaner?
Richer. You would increase the normal table. Leave the boundary alone unless your notmal is close or exceeding.
I could throw something together for you to try if you like
Last edited by anniversaryss; 04-14-2019 at 05:38 AM.
1997 30th SS. Torqhead 24x, TFS heads, 223/235 cam, 4l80e, S60 D1SC 14psi
ls3-10%ve.hptgas run.hpl
here is the latest tune and scan. im also having a issue with the first cold start, I have to give it throttle for a minute or so to keep it running after that its fine. my ve is kinda all over the place I just put this motor in the car and is way different than my last motor
Try adding some base airflow in the area of cold start. You could also add to your start up airflow and delay/decay it longer if its just a start up issue.Originally Posted by green440
I would work in getting it running then do your VE. And come back to idle. If i get a chance tonight ill look over your log and tune see if anything stands out.
My cam is similar but diff motor same pcm
Last edited by anniversaryss; 04-14-2019 at 09:36 AM.
1997 30th SS. Torqhead 24x, TFS heads, 223/235 cam, 4l80e, S60 D1SC 14psi
After reviewing the datalog, you definitely need to adjust your TB minimum air screw. Looking at the last 10 seconds of the datalog, after the engine was up to temp, the IAC position fluctuated from 115-165. It should be in the 40-60 range. I'll bet a lot of the idle issues will go away once you adjust the screw properly. I'd start by adjusting the screw at least 1 full turn CW. Then bring it up to temp and see where your average IAC location is...
any help u guys give me I will take. cold start is the biggest problem I have now. I will try to turn throttle blade screw so it open blade more to let in more air, but at the same time don't I have to decrease base running airflow or car wil idle high? weather is shitty today so I cant go out and drive car
You have a lot of base airflow on cold start. You'll have to reduce it some after adjusting the TB screw. The right side of your BRAF table looks ok though. BUT, don't do any of that just yet. Just turn the TB screw and that will make a big difference.
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