Large idle surge when coming to a stop

[GHuggins]

Engine temp wasn't hot enough to know 100%, but you're anywhere from 10 to 20% off in places right now just with that quick log. I still have to correct your tb.

[GHuggins]

You'll need to load this one then dial in your VE and MAF tables.

[bk2life]

You'll need to load this one then dial in your VE and MAF tables.

thank you

[GHuggins]

I should also mention not to be surprised if torque and timing are all different again. You can touch up torque at a hot idle in park with the ac and heat off after a drive if you need to. If the idle timing is way off i may need to tweak your torque model using a hot driving log after the last changes are loaded.

[bk2life]

I should also mention not to be surprised if torque and timing are all different again. Y.

yes it appears everything is off. I uploaded your latest and went to a local hang out last night, so here is a 10 minute drive to the spot.

I did nothing just uploaded and drove. It hangs at 1200 ish for an idle.


log to mixteca.hpl

[GHuggins]

Write entire. Do a throttle clean reset. Set the base temp before writing. Then drive and hot idle. Torque model should be closer for you now.

[bk2life]

Write entire.

still 1200 RPM idle
past that seems to run/drive normal
lots of adjustment still needed according to the log

hers to miine.hpl

[GHuggins]

It's most likely going to have to be forced since it's been f'd up for so long. Basically going to have to force the throttle to relearn. Also whomever tuned it prior changed some of the idle torque lookup references table for how much torque it'll try to pull to close the throttle, which on it's own can make one rev. You can load this one and let it idle a while after performing the throttle clean reset and see if it'll come down.

[bk2life]

load this one and let it idle a while after performing the throttle clean reset and see if it'll come down.

a couple of minutes, but no idle didnt come down.
if i force it to 600 it will, but without still 1200 idle

higgnes 5.hpl

[bk2life]

Currently have both positive and negative cables together to drain any power from capacitors or anything like that.
Will keep them like that for approx 15 mins.
Will rehook up battery, key on, engine off, will do the 'throttle relearn' with the special functions. I never know if that button works, so i will push it 10 times in a row. then i will start the engine, and push it another 10 times in a row to make sure it did it's job since there is no way to verify.

I will reset the fuel trims and then go on an approx 20 mile drive. the drive will be through a neighborhood then to the freeway and back.
This should give it plenty of drive time to heat up, adjust its self and whatever else might be needed.

Here is a pic of the engine.
nothing big deal, cam, dod delete, L86 intake and throttle body, long tube headers, dumped before axle, stock trans and convertor, with 4.11s/tracloc
Been this way for nearly 3 years, and swapped the intake/tbody about a year ago.

Biggest issue right now is the 1200 RPM idle is not fun for driving in stop and go.


engine.jpg

[bk2life]

1 hour and 12 minute log

idle same 1200.
at end, in my driveway, in park, goes up to 1400 rpms

i guess its too big to upload

will mail to you higgins

[Alvin]

Try this as a test.

jamie silverado 2024 (5.test.hpt

[bk2life]

Try this as a test.

i didnt see this until now.
before i try yours, i pulled 30% of VEE and VT down low at idle.
I also multiplied by 50% half the fuel trims i had logged in the VEE.
And modified the MAF via the log numbers.

I was tryin the big pull of percentage to see if i can get this thing to idle. Currently on this 'tune' it will surge from about 800 to 1200 for about 2 mins then something happens and it goes to a near steady 1350 idle, steady like barely any visual movement.. i got curios so i tapped the throttle and it shot up to 2500 rpms and wouldnt come down. I then just turned the ignition off. Waited 10 seconds and restarted to see what it was doing and it was back to the 800-1200 up and down.

here is the tune and the log, and i removed the 30% for testing reasons only. wanted to get some ideas of where this 1200 idle is coming from.

idle after pulling vee vt maf idles around 1000 up and down i tap on acc it goes to 3000 rpms.hpl
adjusted MAF VEE AND VT STILL AT MINUS 30.hpt

Alvin, i'll down load yours and test it here in about 10 mins.



.

[bk2life]

Try this as a test.

i uploaded yours to try.
it surged in idle from about 800 to 1300 for nearly exactly 2 mins, then went near steady idle of 1200
check out the log

alvins test log.hpl

[GHuggins]

So tapping the tb got it to idle down??? Just got back from my MRI. Will take a look in a bit. That VE, torque model and everything should have been really close to what you need. Putting the torque model back stock will make things worse as the map side determines the idle position. I've actually done a few of these and never had one idle high like that. Raising the MAF 15%, making it overly rich is how you get it to try and idle down, but from the sound of what you said, I'm wondering if something's up with the tb. All I did was fix your post issue when it started idling high and as stated that shouldn't have done that... You can always reload the original tune to see what it does. If it idles normally then one of those post settings are causing a different problem that I havne't seen from them before.

[bk2life]

1 So tapping the tb got it to idle down?
2 I'm wondering if something's up with the tb.
3 All I did was fix your post issue when it started idling high and as stated that shouldn't have done that.
4 You can always reload the original tune to see what it does.
5 If it idles normally then one of those post settings are causing a different problem that I havne't seen from them before.

1 no tapping the throttle raised it up and it never came down. I turned the engine off.
2 throttle body was brand new GM, been working fine since i installed it. Jun 23, 2023 was when i installed the intake and throttle body.
3. i understand
4. I think i will try that either late tongiht or in the am. I'llwait until you look things over again so i dont 'jump the gun'
5. Its got to be something with one of those settings. I just wish i knew more of the gen v, im so much at a loss here

[bk2life]

You can always reload the original tune to see what it does. .

so curiosity got me.
i uploaded an earlier unmodified tune and it idles fine, drives fine, nearly no issues. I say nearly because its not perfect

here is the tune, here is the log.


this was only a 'write calibration' not an 'write entire' performed.

uploaded old tune no entire write just simple upload.hpl
jamie silverado full read 2024.hpt

[GHuggins]

HPT changed something a little while back. Depending on which version you have doing a regular write can change the background stuff. I just tell people to write entire to make sure it's done depending on the version they have. Did you try the one I emailed you? For it to be driving fine, you were complaining about it lunging and running rich on decel due to the cal issues. It's just one of the settings for the O2's that's not playing well and needs to be figured out. If you want to drive it and let it learn back all of the previous issues then that's up to you.

[bk2life]

Did you try the one I emailed you? For it to be driving fine, you were complaining about it lunging and running rich on decel due to the cal issues. .

i saw your email a few minutes ago. No i have not uploaded your latest.
I only drove a few minutes, around the block, the vehicle appeared fine, as in it was idling when it was supposed to.
to me this verifies its not mechanical, it's just something in the tune. The throttle body is 'tight' no air leaks, no vacuum leaks.
just doing some simple diagnostics to be able to point at the tune.
Now what it is inside the tune, i dont know. Still getting there.
I will load up yours and report back.

your time is much appreciated.

[bk2life]

HPT .

uploaded your latest and went for a quick ride around the block.
was able to let it idle and two WOT runs up to 60 mph.

Ran and drove fine, idled nice. made about 10 stops, didn't feel anything weird.
I'll be able to make a 20 minute datalog tomorrow when I make a run for lunch.
I dont know what you adjusted, but it's the right thing that made it idle correctly.
I installed your channels as well.

higgins tune 6.hpl