Hey Everyone, so im new here and just a few months ago acquired my first LNF SS/TC. Love the car but I have put a few hundred miles on it now and was not able to get any accurate info on its history, but the LAST 6 is 38960, if anyone has any info about who tuned it lmk. The first few hundred miles I drove it I have been pretty conservative with it because I know that it could easily hurt itself if the tune is off and the previous owner could only tell me that the guy before him had done 'some tuning work' so I thought, ok ill be easy on it until I get hp tuners and have it checked out, well until the other day, 15 psi was the max boost I had ever seen so I thought maybe it was not too aggressive, well I guess i was not pressing all the way down on the throttle or something because the other day I made a point to see what WOT was like and the boost guage tried to go WAY past 15 but before it actually made power it broke up and flashed the CEL, Then it went off, scanned it and no codes not even stored codes?? Scared to try WOT again without some info. It seemed VERY aggressive. Any help? Sorry so long but.......

 

Hello and welcome to the site. I'm assuming you are on the stock K04 so your boost should be around 22 to 24psi. Yes a log to check on your trims is really important. I would throw a new set of AC Delco plugs in it. NGK plugs seem.to misfire in LNFs so make sure you run AC

 

Thank you, I put new A/C Delco 41-108 iridiums gapped at .032. I have refrained from going WOT until I get the mpvi4 to do some logging. And of course figure out how to use it! Been trying to watch videos on understanding VCM scanner but its hard to follow without it in front of me. It feels sluggish up to 80% throttle tho it registers 15 psi of boost at that much pedal. Only driven like 40 miles since the incident since I dont daily it. No more misfires yet, but also no WOT

 

I'd mainly look at your trims and get those under control first because bad trims can cause many issues. You also need the scanning config to read the car.

 

Not sure what you meant by scanning config?

 

Im guessing you were referring to having the right PIDs recorded when I datalog. I dont have hp tuners yet but when I get it in the next couple of weeks ill try to make sure I get all the right ones recorded.

 

does it have stock coils or them red zzp coils?

 

It has stock coils. Crazy thing is it has been running pretty strong the last couple of times I drove it. Of course staying away from WOT. Which sucks because I have a base model if I want to go slow! Anyway, I installed zzps lnf fuel filter and im going to get hp tuners soon because I did a plug read on a new set of plugs I put in and it looks to me like there is aggressive timing going on even at 80% throttle. Plugs dont lie so I absolutely want to get the tune checked out before something bad happens.

 

Ya once you can scan the car it'll be much easier to figure out what's going on.

 

I do have a regular innova 5210 scanner that reads codes and does live data. But it doesnt record or anything. What I jave been doing, is reading a ton of stuff on tuning the lnf, which has taught me that I basically dont lnow squat about the complicated tuning process! However, I know enough about cars to know that if the tune is overly aggressive and wrong, it can turn my pretty little silver coupe into a driveway ornament pretty quick. So there's that. I drove it about 20 miles today just to keep it fresh, and check to make sure my ZZP lnf fuel filter install was not leaking. I spent $20 on some of that silver insulating sheathing to go over the fuel line to insulate it from the turbo heat shield. Probably not necessary, but I was a helicopter mechanic in the service so I dont like to take chances. I dont know if ill ever be able to comprehend all the tables and stuff in hp tuners so I feel like getting the interface solely for the purpose of logging and getting help remotely is probably worth the money. Ive heard mixed reviews about ZZP's remote tuning but at this point, I think renting (and keeping) the mpvi4 interface and laptop from them with 2 credits included is probably the most cost effective way to get set up with their tuners input being included for a grand total of ~$900 seems ok. Reading the hptuners forums kind of makes me skeptical of everything and everyone! Lol! Man this stuff is COMPLICATED! BUT....I LOVE ❤️ the car! Just want it to perform as it was meant to and then go UP from there. The right way!

 

Good luck with the car and your build. You said you can see live data what are you STFT and your LTFT that will tell us what we need to know.

 

Ok, so i drove the car today to drop the hood off at the body shop to get a dent fixed in it and repainted and plugged in the scanner to lool at the fuel trims and the short term trims are like 0 at idle and fluctuate quite a bit not really going past either 7%+ and 7%- but mostly the numbers were lower than 7. Here is the crazy part....the LTFT was NOT MOVING. just stuck at -5.5% the entire way there. Locked. Then on the way back after it was shut off for a coulple of hours when i started it back up it was in OL again and it quickly went into CL and the LTFT was locked in at -7% all the way home like 10 miles. Also i emailed TRIFECTA to see if they could tell me if they tuned the car and they said that its easy to tell if they tuned it because the cruise control ON/OFF button will select stock/tuned parameters. So i was trying to see if i could tell a difference without going WOT because i want to be able to tell whether or not my PCM is going to be locked sp i dont waste monet attempting to get this pcm tuned again. Is there a PID that i can maybe pinpoint a difference on when i cycle the cruise button without going WOT and risking popping a ringland? I dont have anything to compare the power of the car to but i know its been tuned because it has CAI, INJEN CP, ZZP CDP, ZZP IC, besides the fact that the time i did give it pedal it pulls pretty freaking hard.

 

Those trims will cause some small issues themselves. Sounds like you need a retune. I like getting the trims around 2 to 3% or at least under 5%

 

Also i forgot to mention that wjen the scanner first links up abd says 'no dtcs' three of the monitirs are red EVA CAT and O2S they are not ready

 

Is the LTFT supposed to be stuck? I thought it was an average of the STFT over time?

 

LTFTs should be more stable after the ECU adds the correction factor into the tune. Your STFTs will change all the time and if the error % is too hight it will take away from the STFT and add that % to the LTFTs.

 

Do you know if the monitors not being ready have anything to do with the tune possibly having the cat overtemp turned off or something? Maybe the evap monitor is off becauee of somethibg with the tune? Or is something not working right so the emmisons monitirs aremt 'ready'?

 

Your have to download the tune to see what has been turned off. Some monitors take forever to ready. I've heard of people who have to pass emissions saying they have problems with monitors readying up. You Evap is obviously working because you have LTFTs

 

Do you know if the monitors not being ready have anything to do with the tune possibly having the cat overtemp turned off or something? Maybe the evap monitor is off becauee of somethibg with the tune? Or is something not working right so the emmisons monitirs aremt 'ready'?

 

But arent the ltft supposed to move? Not be stuck at tge same number for 10 miles of regular around town driving? I have a base model 2.2 cobalt also and the ltft move around quite a bit on that one. Im sure whoever tuned it was in ohio where the car lived for the last few years also. Ive heard that these things are quite reactive to atmosheric conditions or DA. i would think that the PE mumbers or SD tune would be kind of off since i live in south floida and at WOT the thing switches to SD, right? At least thsts how i think it works. When you go WOT it switches to PE tables? Long story short a retune is probably the best advice. Im not racing the car but i bought it for the WOT fun and cool turbo noises! Lol! I have a base model for daily duty! Man the hood being off sounded really cool today driving home! The Typhoon intake really lets the turbo sound out!

 

Are we still talking about your misfire? It has nothing to do with emissions it's the tune. The sensors becoming ready is only for emissions I turned all that off on my car.CAT over temp is used when you have a cat delete or you are trying to make max power and want no limits up top.

No LTFTs are learned over a long time as it uses avg numbers the shouldn't move that much unless you just had a retune or disconnected the battery.

The 2.2 and LNF use completely separate ECUs and the LNF does everything different.

Yes a good time should fix your problems if you get those trims cleaned up