GM STAGE 2 tune
 

i'm running the gm stage 2 tune.

it seems to run pretty rich... the exhaust smells rich at idle. and i hate how the idle is constantly flipping around the timing. so it idles nice and smooth with a nice advance... and then all of a sudden it goes -6 and shakes a little and then a few seconds later the timing bounces up and idles nice. it does this off and on. it doesn't always go to -6. but it will bounce around to what i consider normal timing advance at idle to very little advance. it makes the idle shitty.

also there is 50% of the time a hesitation shifting gears especially if you don't run the rpms up high and shift really smooth.

its very annoying and doesn't fit my driving style.

other people running the gm tune see stuff like this? would the canned tunes from ottp or zzp or whoever run smoother?

I would say if all that has been done is the stage 2 components and the stage 2 tune, you have other issues. I wouldn't waste my time with a canned tune, rather take it to be looked at and then tuned.

Really. If you don't have a clue what you're talking about don't respond

My car used to do something like this during idle however ran fine during normal driving. It would do the shudder like you say and my AFR gauge would read very lean and it would do that for a second and then it would consistently switch to high rpm idle and just stay there at like 2,000 rpm. The problem was consistent and the characteristics of what would happen didn't vary much. At first it would idle fine but after idling for a while it would studder studder studder and then Waaaaaaah hold steady at 2,000 rpm. It would also have wonky idle sometimes where it would rev rpms up and down unless I intervened with the gas pedal and tried to level it out. My idle still wobbles sometimes and I have a completely different setup now and I am convinced it is the tune. It doesn't do the studder thing anymore but it still will dip and sometimes even die if I go from driving to immediately letting off and coming to a stop without blipping the throttle. Really the only thing mechanical I could think for you to check for would be vacuum leaks.

If the tune doesn't fit your driving style don't get a canned tune. You're going to want a custom tune so you can have the tuner adjust the drive ability to match what you want.

Do you have a scanner or an OBD2 to bluetooth connector to see what the fuel trims are doing and if there are any pending codes?

What mods are you running with the stg2 tune, a GM stage2 kit or a kit from zzp/ottp/other

Umm... I took a NA engine, Supercharged it and tuned it myself, not to mention I have been doing this probably before you were born.

I'm using torque to watch stuff.

I remember now I already figured out the shifting hesitation deal. It's the torque management... When you shift gears I can see the timing advance going from normal to very low. Typical torque management crap.

When the adv bounces around at idle the rpms don't change and it's not really a shudder or anything it's just less smooth. The vacuum stays around 18hg even when the timing bounces.

I'm on the fence about buying hptuners just because of the cost. If there was a d cent canned tune I would be happy. I know they give you options to turn off trq management and all that

Oh and the fuel trims look pretty normal. I'll watch it again this morning when I go to the gym

My setup is basically gm stage 2. 71.9mm pulley (2.8) bay long tube no cat dual pass and front mount h/e.

The entire top end is new and all the sensors are new except the maf although I've cleaned it recently. I also cleaned the tb recently.

It's pretty apparent it's in the tune. I'll probably only be happy with hptuners and tuning it how I want. I wish there was a cheaper or freeware tuning ability like there is for honda/Acura ecus

It also did all this annoying shit when I first bought it when it was all factory gm stage 2 stuff

Thats a great way to get people to help you.

i don't need his help if his help is "take it to someone"

What are your fuel trims for idle? (LTFT and STFT) Does the load change when the idle stumbles? How long does the idle stay at low timing, is it just a quick drop down and back up or does it stay low for a second or two then adjust back up?

Try finding hptuners used, it may take some time but eventually someone will be selling one. With the LSJ you def want the pro version so you can log your wideband.

i'll watch the trims here in about an hour when i head to gym. last time i watched they were normal.

the timing only stays low for maybe half a second or a second i guess. its 12.5, 12, 12, 12.5, 6, 12.5, 11, 10, 12, 5, 7, 12, 11 etc... you can feel the change in the idle when the timing dips but the rpms stay the same and all that. its just annoying because i like smooth idles. if it just sat there at 12.5 the entire time it would idle smooth as glass. i haven't watched the engine load % at idle but the throttle % stays basically the same i think its about 15-16% while it idles warm

My point was to take it to someone to tune... If all that was done was the stage 2 upgrades the stage 2 tune from GM shouldn't be running that bad. If you have tuned so many engines, why are you leaning towards a canned tune and monitoring data with Torque :lol:

because i don't want to spend 100s of dollars to tune a $6000 car

and i've seen lots of people complain about the gm tunes being too rich. and the torque management is in all of them and it causes a lot of this

and it doesn't "run bad" there are just a few things that are really annoying. the car rips pretty good for what it is. the idle is fine but it annoys me. its like how most engines feel when the a/c compressor kicks on when you have the defrosting going. i hate that

Sounds like either there is a sudden added load (alternator or something else) and iirc in the GM tune uses the VE table at idle could likely use some cleanup and timing adjustments. I don't recall what else HPT has available for adjustments. But its hitting me now, you're running 42lb injectors with a 2.8pulley?

yea it bought it like that.

i do watch the iat2 on torque closely and i've seen it go up to maybe 130f in a to top of 3rd gear pull. this was when it was like 95f outside as well.

i don't beat on the car honestly and ive seen people say its maxxing out the injectors and i've seen people say its not.

i'd like to get a wideband and a 2 gauge pillar pod sometime. its been running like this for 104k miles and 99k of those were without the dual pass

im heading to gym here in a few mins and i'll watch the fuel trims and the engine load and anything else i can think of and report back.

i might try the logger but its been a long time since i've used it and i dont really have time to sit and figure it out i'm super busy all day.

the last time i used it was with a old HPCR cummins watching my injectors because of a funky idle and ended up having to put in all new injectors :o big $$$$$ :(. after that is ran amazing tho

So ur basically saying your just anal and picky and too cheap to tune a performance car u own? Why does it matter what the car is worth? Tunes don't get cheaper cause ur car is worth less, and why would it matter for tuning? Just put it back to stock

Unless there is a magically area in Oregon that is a mile high you're maxing your injectors out. You should get a wideband at a minimum.

the timing jumps around at idle to keep the idle speed in its target. they dont use the throttle blade to adjust the idle speed, timing is much better for fine idle speed adjustments. what your seeing is normal, and if you change it so it wont jump around you will have a terrible idle quality.

and 2.8 pulley on a stage 2 tune is generally a no-no. injectors are past maxed. you could do it with a lot of water/meth, but thats not really a good idea. for that pulley you should be running 60lb injectors.

I'm sitting here watching it idle now and I don't feel it as much right now. The only time I felt it is when the timing went from 18.5 idle to 0 and then back up to 12ish.

Stft is bouncing around -3 to +5 but usually between -3-+3

The engine load % is staying around 25-27
Throttle % is staying around 15-16%

I can feel and hear the change in the idle that annoys me when the timing going 5 or below. Once it goes back up 10+ is smooths out.

I guess I might just have to deal with the less than smooth idle considering it's a i4 and I'm guessing the cams aren't super mild like some other small i4 engines.

Super lazy too.

Other platforms have free software, or carb tuning on other boosy projects... Or at least cheaper tuning software. Hptuners just has the market cornered with gm products I guess so the price is high

It might make more power up top with a 2.9 pully but less torque down low I'm guessing

I'm also assuming the kncock sensor is taking timing out when the injectors max out causing a drop in power at high rpm. But honestly I don't feel the power fall off at all up to 7200 I've never watched the timing advance closely at the top of any gear. Might try that sometime when the roads are dry

I've been putting 93 in it at least ;)