Ugh... I can't believe I have to post this. Today on my way home from work I was merging on to the highway from an exit. I decided to have a little fun so I NLS'd 2nd to 3rd and 3rd to 4th. 2nd to 3rd was beautiful. 3rd to 4th choked as if I misfired but only one pop and the cel didn't come on.

I continued on my drive and thought nothing of it... my intercept gauge cycle by ltft and stft. As this point I nearly **** myself. My ltft was -20.0 and decreasing pretty quick. My stfts also jumped very negative. I eased off the throttle a bit to about 10 percent throttle. My stfts hovered near 0.0 on the negative side slightly. My ltfts started to decrease to -15.0 percent.

Ive concluded that when ever I throttle it the stfts and ltfts go crazy negative. When I got home I listen to the engine while it ran. Sounded like a new ticking noise... could I have floated a valve and caught it before Cel tripped? Its coming from right behind the valve cover... its faint but noticeably different than before. The sound changes with throttle. Anyone know how to pull apart the valve cover to see this in my area?

I could be imagining the ticking, not sure really. But I do know my car behaving totally different now than it did before the car had a hiccup.

 

is this what happened to cmiller as well?

 

lifter?

mine shatterd on a 3-4 nls

 

I dunno... its one of those things where I need somebody with a good ear and see if they hear the same odd noise, lol. I can still drive the car if I baby it to keep the trims up. I really dont want to make a retarded dealer visit... and if its something cheap to fix, i'll do it and for go the dealership raping.


oh also just to let you guys know, the car is stock with bolt ons. Meaning its never been tuned/calibrated. I have the mods in the sig.

okay guys, this might be my issue. Read my symptoms and read this thread.

https://www.cobaltss.net/forums/2-0l-lnf-performance-tech-153/solenoid-issues-whatever-you-want-call-revisited-222294/

again Im not sure if my car is really making a new noise, might be me imagining its a new noise.
Their fuel trims go really negative too however I didnt trip the cel probably cause I caught it.

 

Samething sortive happened to me except my popped like 5 or 6 times no joke and it felt like it wanted to die.

I had steve (Trifecta dealer) datalog it and send the file to vince and said that it was something to do with my fueling system

I dont know how with 6k miles but anyways the cel came on and started to falsh a couple times so we check that

Ramdom misfires in cyl. 1,2,3 and then something else but I can't remeber

So I'll try changing the press. reg or pump and see if that does anything

He also said that the Comp. was calling for more fuel but the car wasn't giving it

 

I just tuned someone here with a dejon CAI and charge pipe, he was throwing MAF codes due to his solenoid. after about a week of fixing the trims i found the thread on the evap solenoiod. disconnected it, got the trims perfect. hes been driving it for a week now with no problems.

I can help you out if you like.

 

yes that would be great! I will not be available today or tomorrow but I should be available sunday or anytime after 5pm next week. This freaked me out at first when I saw these negative fuel trims and I couldnt find any sort of unmetered air loss... I listened to my valve cover again today and I still think I hear a noise that shouldnt be there... When I rev it I can't hear it though, just hear the ticking of the oil pump/ fuel pump combo.

....Someone just told me its because I have an aftermarket intake on with the stock tune.... Im about to go punch a baby... This is not that. This is different. This is a real prob.

I will throw my stock airbox back on just for ***** and giggles to see the aweful fuel trims with a stock airbox and prove some people wrong... I mean how could my car for the last 2 months of having an SRI drive totally fine (hell, I even took it to the track and had some good times) and now the car ***** the bed over an intake?

 

Well, I'm less likely to blame the intake 'cause it has been fine, but have you checked to make sure everything is still tightly seated as it was before just in case beating on the car a bit jarred something loose?

 

in my case with my friend, his fuel trims went from +/- 2 to about -15 just from the intake. not saying its the issue here, but his fuel trims defantly went out of wack.

if you want you can just unplug your evap sol. and watch your ltft. they will freeze. i did mine while the car was cold and not running. not sure if it freezes it where its at, or if at 0. Ive only had one lnf with this problem.

the only problem ill have is you need me to adj. fuel trims ill have to register your car with my hptuners. i do not have any lnfs unlocked yet

 

FYI if a lifter is sticking, sometimes when you rev them the extra oil pressure will quiet them down a lil. Not saying that is your problem though. I really like your idea of the pure solenoid, but you never mentioned if you can even hit full boost or not.

Also is this a constant issue? Or does it come and go?

 

If this is the same problem i worked out, it comes and goes. weather here changes from 100 to 70 degrees from day to day. which can sway fuel trims enough if that sol. was bad.

when i had the problem, idle was sputtering, normal driving seemed ok, but once you got on to it, it just fell on its face didnt wanna go at all. Adjusting the fuel trims didnt do it for me.

https://www.cobaltss.net/forums/show...ighlight=purge

and a simple search on hptuners forum for ltft and stft tuning you will see BYT guide to tuning fuel trims. which includes unplugging the sol.

Which i never got to thank BYT for the help, so THANKs lol

 

Okay further info is needed, here it is:

This is constant, it does not come and go. Its like the story Dr. jekl and Mr. Heid.... only, the car stays as Mr Heid and doesnt go back, lol. Something definately happened during the NLS... Thats was the magic potion that made my car awnry.

Yes I can hit and hold full boost, but I dont do it for too long cause the freakin ltfts "negative sky rocket" or rather sky plummet at WOT.

It appears as though the ltfts increase in negativity rate as I increase the throttle rate.

No CEL.

No missfires recorded at the time on the Aeroforce. well one, but thats insignificant. It was on cylinder 2.

Idles fine for the most part.. Sometimes I've seen it go positive at idle by as much as +10%

 

I am not discounting the fact intakes can skew the MAF in these cars. The Card style MAF is hypersensitive to changes, i used to have it as its also used in the LS7 on my LS1... **** was annoying as hell.

However, CudaJoe has been monitoring fuel trims daily for 2 months now. Unless a coupler came loose or something drastic changed if it was the intake he would have noticed.

I was second with that intake and easily have 5,000 miles on it with no skewing on the maf. But you linked unplugging the evap purge sol so thanks for doing that(i forgot there was a post with pics already), i have really been wanting to test that, but i always forget by the time i get home lol. IIRC CSRT-4 owners do this as well?

 

yeah fuel trims have been fine for quite sometime. The NLS was a catalyst here. Something happened right then and there and I caught it before I let it get to hairy. I checked the intake first thing to be honest and it was still holding firmed, the sensor didnt collide with anything, and the couplers were connected from what I saw, unless there is a tear in the back of the coupler. Further inspection tonight when I put the stock airbox back on for ***** and giggles.

Just thought of something... since the MAF is seated so close to my heatshield... could a NLS have cause my engine to torque the MAF into the heat shield seeing how the intake is ONLY bolted to the engine.... the engine moves then so does the intake?

 

i prolly should have been more clear sorry. when he was having these problems, i adjust the fuel trims aback to +/- 2 car drove amazing for 2 day or so. then back to ****. the only reason it went back and forth is because everytime i adjusted the trims back. if left alone it woulda ran like **** all the time.

to be honest i thought it was a maf problem or coupler myself, because doing mostly lsj's ive had very little problems with MAFs. but the lnfs seem way more sensitve with CAI.

try unplugging the sol. and see what happens. you should should see the ltft stay right at 0 and not move.

after tuning with it unplugged, car is noticable smoother as well...

 

The maf is fairly tough, and if it was broke i would assume it just wouldnt work at all. Mine is close to the heatshield like yours and i havent noticed it touching at all even during NLS. I cant see any indication of rubbing or hitting at all.

Try unplugging the Evap purge should be easy and quick to do, and it would answer a lot of questions.

 

It is a boost leak check your CPs and IC.

 

I agree,

My CP came off and I jumped to -15 within a mile. no CEL no other symptoms besides the jet engine sound coming from the open charge pipe.

 

iv had my car go a bit crazy on a nls, i just turned it off and back on and it fixed itself.

 

Lost boost. Got an engine code p0101. I noticed I COULD NOT get full boost when this happened. lol. the most I got was 12psi. and it dropped real fast when letting off the pedal. going to take my bumper off now and check the intercooler.

found out my MAF back screw was loose. there was dirt all over the rubber gasket but the sensor looked clean. will test it as soon as someone moves their car.

 

If that's what it is, I'll take a large chocolate chip cookie for my earlier post in this thread thanks . Hope the solution is this simple and you get 'er back up and running normally!

 

Point for Permafried!

 

That is the code the car gives when you have a big boost leak! Ask me how I know. I doubt the one screw being loose was the issue. The MAF stays put pretty well because it is under vacuum not pressure.

 

LOL , this happen to me first trial installing the hot side .. They said be careful because you might crack the plastic and so I was a little too careful ..

 

i got the p0101 code when my IC had a crack in it