1.4 is not liking the high boost tune, and i cant track down the issue.

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ThatPostalGuy66

New member
So for the past month i have been having an issue with a tune i purchased from zzp for my 2016 LT hatch, which for the most part has been very disappointing because i was really excited to bring all my mods together with a tune. But anyways, i purchased the tune and got the hp tuner and sent my stock file to zzp and they sent back a file based on the stock tune i sent them. With that tune and every high boost tune i have got from them i have gotten really bad sputtering/choking (almost as if the motor dies and come back on but without the actual electricity cutting out) in the low rpm range. It honestly is just heavy throttle through 2-3K rpm range that it does it. I am really doubtful its the tunes or the tuning that is causing the issue. Because i have seen the tune logs, and the car seems to run fine on the stock tune file. Which i have not gotten a CEL or flashing traction control light indicating it put itself in limp mode. the tune files he has sent me that have been stock until after that rpm range have worked. Which is very strange for a 25k mile car.. I have looked at so many things and have checked so many things. obviously the most common issues first, being check valves. replaced the spark plugs (even though the ngk laser iridiums in there had very few miles on them.) tried a different ignition coil, did a compression test on all four cylinders and all were at the same psi on my gauge which i believe was 180psi, i checked and made sure all my silicone couplers were tight on my zzp FMIC (even though it did just fine with boost in the upper rpm range). I checked the wastegate actuator and the pressure on it seems heavy but normal. when i go onto hptuners and try turning off injectors it doesn't seem to turn them off for me to test them. my mpg honestly seems a little low for mixed highway city driving. i am at 26.3 mpg currently and have been trying to even drive conservatively. I have cleaned the MAF and MAP sensors. and honestly i am just running out of things to check. i put my stock down pipe on and took it to the stealership to check the car over, and of course they said everything is fine. because they're not going to go over it with a fine tooth comb and i can't exactly tell them hey whenever i tune my car and void the warranty its choking in and out of consciousness like it has TB. But when i put my catless back on i was going to check for shaft play and possibly check the BPV for issues. But i am honestly just lost on what the issue could be. If any of you guys have suggestions please let me know. i am also willing to possibly send my logs if doesn't somehow reveal zzp's tune, obviously for legal purposes.
 
RMinNJ

RMinNJ

Active member
Any codes..., PSI is ??when this happens? I know when Ive gotten limp mode from over or under boost I get codes but no CEL.
 
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Italianjoe1

Member
I'll look at the logs in HPT if you want, the logs have nothing to do with the tune. I would love to see the tune to compare to a stock file and see if there's anything there that can be the cause, it sounds like spark blowout to me but it's unusual that it's at lower rpms, but the tune could be commanding a lot down low. What did you gap the plugs to?
 
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ThatPostalGuy66

New member
I was told gap is preset on iridiums. .027 which is the standard for the AC delco plugs. No codes at all I've tried running codes after it has happened. I will have to check the logs to see what it is commanding for boost. I can send you the log. But cant send you the tune unfortunately.
 
wasteoffilm

wasteoffilm

Member
Is that 16.5psi over atmospheric or absolute?

If that's absolute, or if psi is dropping low when you have the issue, you *might* want to back off the preload on the wastegate actuator.

I had some similar issues with my warranty replacement turbo, and the wastegate had like 6 turns of preload from the factory. It would cut boost to about 2-4 psi over atmospheric when tuned and pulling uphill. I currently run mine with only a half of a turn.
 
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ThatPostalGuy66

New member
I believe that is absolute. It's funny I told the dealer it seemed pretty heavy. And they said "it is supposed to be heavy". I will double check and make sure it's absolute. Could that be a contributing factor with my crappy mpg. Because I always almost wondering if I messed up my evap purge solenoid because I've pulled the rookie move and topping off my tank a few times... But I haven't gotten a CEL. My only issue with adjusting the preload is it is marked/sealed, so if I adjust it they could try pulling some crap to void my warranty on it if it ever fails.
 
wasteoffilm

wasteoffilm

Member
My new turbo had some shaft play, wasn't that much different than the old one. I suppose a wastegate with excessive preload might lower fuel economy. When I picked up my car from the dealer after the warranty repair, it was on the stock tune, but was pulling really strong down low, like it was the old Trifecta tune with a overly sensitive throttle.
 
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ThatPostalGuy66

New member
Yeah I confirmed it, it is absolute and it is getting as high as 18psi right before it goes into it's choking. And then the o2 mv goes close to 0 before the power comes back on. Yeah I am getting 26.3 with mixed city/highway. And it seems to keep going down.
 
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ThatPostalGuy66

New member
.22 didn't fix the issue.. should I go lower? My only issue is it misfiring when it's not under boost if I go lower. When I went down to .25 it seems like it was missing on initial start up. Went back to .27 and it was missing and I think I just never noticed how much it was missing. .22 seems to fix that issue but does not fix the blowout or whatever is happening between 2500 and 3000 rpm
 
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Italianjoe1

Member
I gotta look at the logs. I still haven't fired up my laptop. I was supposed to tune a Camaro this week but he's waiting on some parts. I'll look at the logs this weekend and see what jumps out at me.
 
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Italianjoe1

Member
On that log, where are you getting what you are feeling? What times in the log?

What I see that concerns me, it a TON of timing in the tables down low, which just isn't necessary in a "high boost" tune. I'd be curious to see the tune to compare it to stock, but I understand you don't want to send their info out. I believe, if it's tunerlocked, I may not be able to open it anyway. I certainly couldn't make changes to it or do anything productive, but if I could see some of the DAL and demand tables in relation to the timing maps it would help me see why it's so high.
 
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ThatPostalGuy66

New member
if you look at 02:51:22 and zoom in you will see tps is 100% and if you follow it up you will see that it goes up to around 2770 rpm then drops 200 rpm with the tps still at 100% thats when it is doing it. and you can honestly just check for when the tps is at 100% and that where you see the issue. in low rpm. so maybe high timing for the full load? i can send you a stock log and the stock tune. which should tell you timing.
 
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Italianjoe1

Member
I have stock tunes, you said it only happens on the high boost tune, I'd like to know what they changed. I had my car on 25+psi with no issues.

At 2:15 in that tune when you're at high TPS, the car is still in closed loop, not going into PE mode. I had this issue with the Camaro when I edited some torque management tables. Put them back to stock and it went away. That entire segment, when you are in boost and full throttle, the car has to be lean, it's commanding 1.0 Lambda and not going into power enrichment.
 
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ThatPostalGuy66

New member
that is interesting. what do you suggest i do? i believe they added power enrichment in the tune and did spark timing. and also upped the torque limit values?
 
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