Hi all,
I started this thread in the transmission section as the issue started the day I picked the truck up from having the 4L60 rebuilt. I have a log of the issue now, hunting idle, it starts at 2:06 and gets worse from there until I start moving again. I am not a tuner, so can't really figure out what I'm looking at in the log, but it appears to me that the timing is getting pulled and then the RPMs drop. If that is the case, can somebody give me some insight as to why this is happening, or if it's something else, could you point me in the right direction? I've looked at everything the rebuilder would have been around, exhaust, O2 sensors, air intake, trans wiring, etc, and it all looks fine. I still feel it's something the rebuilder did accidently, or possibly it's still trans related, as this truck has never done this in the 14 years I've owned it. Below is the log and below that is the original post I have in the transmission section (I am unable to delete that thread). My tune is at the end. I'll search for "hunting idle" and see what comes up as well. Thanks in advance for any help!
20210830 A.hpl
Placing this in this forum even though it's a running issue as it started after the trans rebuild and I hope someone has some ideas as to what is going on. I've tried searching for this issue, but haven't found anything yet, or I'm not stating the issue properly. 2006 Silverado, 5.3/4L60, mild cam, headers, no cats, tuned on a dyno in 2010 (not by me), 318hp to ground. This truck besides the transmission, has performed flawlessly since 2007 when I bought it, never any issues, always ran perfect. Well, I just had the 4L60 rebuilt (again!!) and after I picked up the truck, sometimes while stopped in gear the idle will hunt, RPM goes from ~500-~700; it has never done this before. It doesn?t do this all the time, and as far as I can tell, it only does it in gear. One morning it did it at every stop on my way to work, and on the way home it didn?t do it at all. I?ve driven it for a while today while logging, and of course it didn?t do it. My thinking is maybe it?s a TCC or solenoid issue, but these are just guesses. NOTES: I?ve put on a few hundred miles since picking it up, truck appears to shift fine, never any issues while moving or in park/neutral, the outside temps are always above 90* (Phoenix), upgraded parts were installed, extra clutches, etc, stock converter stall, dropped line pressure per rebuilder recommendation (back to stock) but issue there before and after upload, never had running issues prior to rebuild.
I?m by no means a tuner, so please forgive my ignorance and unfortunately all the logs I have do not show the hunting idle yet. I?ve setup the scanner to log a bunch of trans PIDs, if there are any others I should be logging to help see what?s happening, please let me know. What I did notice is it seems like the TCC is not unlocking when the brake is applied (10:27:46), and it also seems like its staying locked in 1st (10:30:19), which looking at my program that shouldn?t happen (?). I?ve checked the wiring, and all appears to be fine, nothing disconnected, no broken connectors, etc. Not sure what else to look at, and I?ll continue to log to see if I can actually capture the hunting idle.
This is the 2nd time rebuilding the trans, the 1st time I pulled and installed with no issues (2017?). Here, I dropped the truck off, so can?t verify any parts, work done, etc. Any help, ideas and/or guidance is greatly appreciated!!
20210828 ver B.hpt
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Originally Posted by Matt Vardaman
