Alright guys i got a 2002 yukon i just had a cam install with a stage 2 4l60e and efans and tune, well now when i crank it up it revs to 2500-3000 rpms then slowly idles down to about 800 then when i drop it into reverse or drive itll idle up to about 1100 and i gotta stand on the brakes to stop. now if i put it in drive and hold the brakes for a minute or 2 the idle will drop to normal and act right until i shut it off. then when i turn it off and crank it back up same thing. cold or hot. could anyone look at it and let me know what you see?
You have a positive number in the Over speed table for 1 thing. Your underspeed, You might try 1/2 the values from -12.5 to -100 rpm. you can get the idle sound you want after tuning the idle and part throttle. Until then tighten the reins.
Do you have a DBW TB? or the DBC for this 2002?
Your spark is very low at 10* and probably why you have 3x the airflow in the idle BRA. If you have the DBC then the BRA is wrong.
The tune is set for blended MAF and VE working and the tables have been adjusted. Did you/someone disable the MAF and tune VE and/or MAF only or try to make changes in those tables blended?
Would you log these Modified Idle Channels and bring it up to operating temperature then quick blip throttle 1 time to about 2000rpm and let it come back to idle. If it doesn't return over 90 seconds ok post log file as is, lets see what is going on.
Cheers.
Honestly someone else tuned it. They guy that did my cam swap and he said i just need to get miles on it and it'll line out, but he cut corners on other stuff and i don't trust his tuning abilities at this point, i haven't seen 1 video of another truck doing this anywhere else. I dont know how to tune but everyone is telling me the problem is in the tune. Idk what he did but i see that you see problems with the tune already
Look forward to your answers, is it drive by cable etc... and a log file using the channels I posted.
To load those, you open Scanner and close log file, then the gear icon folder below that in the channels list open the downloaded Idle list is posted and make a log. Bring the engine to op temp of 175* or above and blip throttle 1x to 2800rpm. Then post it.
so it is drive by wire. in this log I took I didn't touch the gas pedal until I stopped in a neighborhood by me cause my neighbors don't like the truck lol but you can see she accelerates on her own too much. also towards the end you can see I just stop for a minute in gear and the idle comes down and it acts right. and my ol lady took it to the grocery store this morning before I got up so it didn't rev nearly as high as it usually does cause it was up to temp before I got in it. the first rev I went to like 4k and messed up but I tried getting what you need. anything else just let me know and I will do it. and I really appreciate you taking the time out of your day to help me.
Well I have a different set of channels for the DBW ok. If you need to drive to get out of the neighborhood I understand, then can you make an idle log and a single 1x blip of throttle to 2000rpm and release. What this does is reveal the Throttle follower air adder and the drive reveals the Throttle Cracker air.
This 1st time log is ok, next time Key-on, then start log before cranking, about 5 seconds of key on, then idle 1-2 minutes at op temp and just idle. There is a lot of info to be gathered here. The after-start and all the modifiers have to go thru the startup process before the idle is actually an idle at steady state. 3 minutes idle is fine too. Then do the blip 1x and ONLY 1x.
Would you log these new DBW Yukon Channels and bring it up to operating temperature let idle then quick blip throttle 1 time to about 2000rpm and let it come back to idle fully, I mean let it return to idle and stay there for at least 30 seconds to allow the idle to return to steady state.. If it doesn't return to idle over 90 seconds ok post log file as is, lets see what is going on.
In the pic attachment, your fuel trims are maxed LTFT and STFT are mostly high when off the gas. I would suspect a vacuum leak. It is most prevalent when off the gas and when you open TB the Blade opening is more influence then the leak. Check exhaust/O2 and intake manifold for any leaks. I would begin with manifold.
2:37 minutes into log: it looks like you hit the gas several times, please Just 1x blip to evaluate the Idle follower.
When you drive,.... everything you do is to have the most steady state airflow possible. Drive increasing pedal ok but not on-off or 10% TPS then 30% then off the gas then back on 35% and so on.... that may get you where you are going lol but it is not very useful for a data log and evaluate your issue. Street tuning is difficult with traffic and all that so just do your best.
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