Topic: High RPM (5100+ RPMS) WOT Hesitation!!!!!

[elff]

I'm gonna break this down real easy

Your hesitation is a lean condition in your tune. The car is retarding itself due to knock. Take it from me. I had this issue to a T. I’m saving you $2500 and hours of frustrating replacing the engine that you will soon blow the rings out of. Run a log and send it to the tuner.

2. Get an update to your tune.  You need to log a bunch of runs and send them to trifecta.  The budget tune is fine on a stock car.  Any modifications and you need to step up to a custom tune.  The good news is - you'll get a bit more power out of it too! 

I asked in another thread if you were re-tuned after adding the new downpipe.   Now that you have stated you have the budget tune, numerous times, my advice is simple.  You need a retune.   

The budget tune is for stock hardware.  You no longer have stock hardware and you no longer have stock airflow and your AFR, IMHO is off.

It was solved after multiples logs he exchanged with the Trifecta developer.

See a Trend?

[MattM]

I log LITERALLY every time I go out and beat on it.  A lean condition is not showing in the logs.  If anything it's a little too rich.  The KR I see is also no different from before the downpipe.

I've been in contact with Trifecta and given them logs and THEY said that me paying an additional $300 to them for a custom tune wouldn't fix these issues..

[elff]

I don't agree with that, but It's your car.  Already stated why in 2 different threads, so I won't rehash.
Good Luck with it.
I'll be waiting for your next thread.

Lost Cylinder# suggestions!!!!!!!!

[Johnny_gxp]

OOO OOO!!! Cylinder 2!

[Sol Asylum]

Things that make it go boom?

[MattM]

I don't agree with that, but It's your car.  Already stated why in 2 different threads, so I won't rehash.
Good Luck with it.
I'll be waiting for your next thread.

Lost Cylinder# suggestions!!!!!!!!

You guys are hilarious!  First, apparently you know more than my datalogs AND Trifecta. Second, you don't read!  I've stated on multiple occasions that this symptom occurred BEFORE I GOT THE DOWNPIPE AND BEFORE I GOT THE TRIFECTA TUNE.

HOW DID TRIFECTA HAVE ANYTHING TO DO WITH THOSE SYMPTOMS BEFORE I GOT A TRIFECTA TUNE?

Now because I took everyone's advice and DATALOGGED my damned car with Trifecta's software and red cord and then sent it to TRIFECTA and was told that a RETUNE WOULDN'T FIX THIS SYMPTOM BECAUSE IT'S NOT LEANING OUT OR THROWING TOO MUCH KR BY THEM you guys are getting butthurt and now telling me I'll blow my car up.  I've also verified what Trifecta was telling me with multiple datalogs in addition myself.  How could I know it's actually running rich and not throwing extra KR in the area I'm having the symptoms if I wasn't datalogging?  I also know how to tune and read a datalog and if anything related to a bad tune stood out to me I would be contacting Trifecta to have it fixed immediately.  Even though I've relayed all of this...according to you guys I should just throw an extra $300 at Trifecta to have my issue NOT fixed..

BTW....I've crossreferenced these symptoms with LNFs on the cobaltss.net forums and NOT ONCE did it have anything to do with a Trifecta tune.  It was always a mechanical issue.

[Johnny_gxp]

May b u haz a streched timming chane, dawg.

[elff]

No one is butt hurt except you.

You provide sketchy incomplete and conflicting information and then get mad when people try to provide some help.
If you were as talented as you think you are, you would have solved the issue, but you aren't, and came to the internet to get help.

FYI no one said bad tune, we suggested re-tuning as an option, due to the facts you provided.
Budget tune, with non stock hardware. 

I personally have no stake in your car getting fixed and due to your attitude and order of work you have done, I feel that it's going to go boom.
Why??
Simple, it's because as you  stated,

this symptom occurred BEFORE I GOT THE DOWNPIPE AND BEFORE I GOT THE TRIFECTA TUNE.

HOW DID TRIFECTA HAVE ANYTHING TO DO WITH THOSE SYMPTOMS BEFORE I GOT A TRIFECTA TUNE?

You have followed a recipe for engine failure.
Car had an issue.
Before fixing the issue, you added a performance part and tuned the engine for more performance.

As I stated before, good luck

[Critterman]

Ask how we all know that you stand a good chance of your engine going BOOM!

[MattM]

No one is butt hurt except you.

You provide sketchy incomplete and conflicting information and then get mad when people try to provide some help.
If you were as talented as you think you are, you would have solved the issue, but you aren't, and came to the internet to get help.

FYI no one said bad tune, we suggested re-tuning as an option, due to the facts you provided.
Budget tune, with non stock hardware. 

I personally have no stake in your car getting fixed and due to your attitude and order of work you have done, I feel that it's going to go boom.
Why??
Simple, it's because as you  stated, You have followed a recipe for engine failure.
Car had an issue.
Before fixing the issue, you added a performance part and tuned the engine for more performance.

As I stated before, good luck

You win big man Elff you put me in my place!  Good job!

I hope I don't disappoint the rest of you when my engine doesn't blow since you all hope that will happen..

Hilarious group I gotta say....

[Critterman]

You just made his day, Elff is all of 2'3" on his tippy toes and lives in a tree.  You may have eaten some of his cookies.

[Gentleman Jack]

Yikes!!!  What is going on in this thread?  We are supposed to be the forum where this shit doesn’t happen. This forum has a single owner, is designed to be user focused and is barely monitized.

OP- do me (and you) a favor. Start fresh. Put all the issues, mods, timeline etc in one clean post below this. Maybe a fresh look at ALL THE INFO IN ONE PLACE will help. The people that are trying to help you here are in the top 10% of knowledgeable Kappa folks. They have seen, fixed, driven, broken, crashed, repaired more kappas then most GM mechanics.   If I had to guess, I’ve personally had my hands on 200 kappas
I’m not saying that to brag. I just want you to know we are trying to help and have seen patterns in what you are describing. There are really only about a dozen things that could cause your issues.

So, let’s start over and get your car fixed and running great!  That way I can get back to drinking good whisky and enjoying my convertible 

GJ

[Steelmesh]

With HPTuners there is a simple fail with the air flow tables that set fueling.  For example you set fueling by changing the MAF tables.  With the E67 in the Solstice, it has a low and high table for MAF.  For example:

Low table: 0 - 5800 Hz
High table: 5800 - 12,000 Hz
(something like that, just an example)

I found out the hard way that changing the 5800 Hz value in the Low and not matching that to the 5800 Hz value in the High table created a bad lean spot because the car doesn't know which value you want to use.  The fix was making each 5800 Hz value equal super simple and related to the tune. This can be easily overlooked if you're not specifically/exactly looking for it.

I assume Matt sent recent logs to Trifecta and they said it's not the tune but take it with a grain of salt, it is so difficult to diagnose anything remotely.  Remote tuning is risky business because the tuner does not have access to reality, just data and customer perceptions which are notoriously terrible.

Consistent combustion needs:
Predictable and Consistent Airflow
Predictable and Consistent Fuel Flow
Predictable and Consistent Spark Timing
*that is the guide here, your mission is that simple: everything that impacts any of the above has to be checked out.

The LNF is ubiquitous, if you can't figure it out via the interweb then you probably have a unique problem related to you the mechanic and/or the VIN specific car of yours.  When something like this happens, I always expect it to be something silly simple and embarrassing to admit especially after tons of diagnosis time. 

Below is a list of some things I haven't heard or remembered been performed during this diagnosis.  Here is where the attitude problem comes into play, saying "naaah it's not that" without proof is the reason you need to do these silly things.  It's like trying to figure out why a tire has a slow leak and the person says they checked the tire tread 3 times and replaced the valve but didn't find anything, and someone says check the rim for a leak and they respond "nah I just bought that wheel it's brand new dumbass."  Like I said before, when I drop a critical part on the floor like a special bolt and it zips off into another dimension never to be seen again, it is actually still in your garage but in the LEAST EXPECTED PLACE on the other side of the garage under a bench inside of a pouch that fell down there 6 years ago.

- Cylinder leak down test
- Intake tract/Boost leak test
- Pull the intake manifold to take a peak at everything
- Pull the valve cover to take a peak at everything
- Pull the injectors to take a speak at everything, try to find a used set and swap them all out
- Inspect the high pressure fuel pump system, pull the fuel pump and inspect it
- Continuity and wiggle test wiring related to the coils, replace all the coils
- Pull the turbo and inspect it, check function of everything, replace turbo solenoid check wiring

The idea here is to run into something crazy like a broken part or melted wire or blown out gasket or something unimaginable. So if you can't do most of the above and more related stuff I didn't spell out, then your only options are:

- Leave it with Werks, ZZP, or DDM
- Sell the car


The value of people responding to posts on a forum is priceless, time and knowledge and experience of people all across the country and world is something that needs to appreciated even if it doesn't work out. Your issue for sure sounds very frustrating, just make sure you catch yourself when your frustrated and not try to project it on people that want to help out and who 'mean well' even if they're wrong at the time or wrong in the end.

[MattM]

I get it.  I definitely did not mean to be so frustrated with my responses.  Half the time I post on here I'm on my phone which means I'm posting bits and pieces at I time.  I should have realized that I posted my pre Trifecta pre downpipe hesitation issue on skyroadster two years ago and not on here, so no one here likely saw that.

When I get a chance to post from a computer to run through everything I've done and everything that's happened to the car since I bought it. 

I did run across something on cobaltss.net for the same strange issue I'm having...In a number of cases there was an issue with the evap purge solenoid,  I'm going to look into that as well.

If I haven't already I definitely want to thank everyone for taking the time to try to help me with this situation.  I do appreciate it even if it doesn't seem like it.

[elff]

It's cool man.  Let's move forward and see what we can figure out.

Do you have a way to post your logs from Tirfecta?   Maybe using a free version of the HPT Scanner? 

From my point of view, since you have a new downpipe, I think your tune can be optimized for the new airflow.  This will help the car maintain the commanded AFR and run better.   It's also been documented with numerous Dyno's by kappa owners that a retune can pull an additional ~20WHP+ over a kappa with the stock cat. 
I agree, this may not be your problem but it's worth it.

Check this out for the Solenoid.  That has been an issue for a bunch of cars and is a cheap fix. 


Steelmesh's suggestion of Carbon buildup is something to look for in any Direct injected engine over 30,000 miles.   It's a big problem on a lot of cars.  That normally shows up as random misfires across the cylinders that may have some valves with the buildup.

At higher RPMs you are pushing more boost.  Maybe do a Boost test and see if at the higher pressure you have a leak.  Pop the IC Pipe off the turbo and pressurize from there and check all connectors going to the Throttle body. 

[MattM]

Regarding the Trifecta logs, apparently only they (trifecta) can see the datalog information.  When I get time from home I'll try to post a snippet of my torque pro datalogs which still allows me to datalog issues going on with the ecu or tune. 

Regarding Steelmesh's post about the coked valves, the thing that sucks when I look at this website at work is for some reason the pics don't show up for me so I didn't know that was what Steelmesh was talking about until I checked on my phone.  To that point, I have seafoamed it through a vac line and it did really clean up the crap in the valves.  A cobaltss.net poster seafoamed his LNF every other oil change then at 70,000 had the heads taken off and checked the valves and they were very clean, so it definitely works if worked through the vac lines.   

Ok.  To start from the beginning of what I've done and what the car was doing.

So....I bought the car in Jan of 2017 from a dealership in New Jersey.  It had 60,000 miles on.  When I got it it idled nicely and ran well, but when I would go WOT it would "break up" (for lack of a better term) around 5700 rpms or so.  I thought it was possibly the rev limiter being set too low (because that's what it felt like).   
Anyway, I get the car home and research everything and find out that Trifecta's tune raises the Rev limiter some so I decide to go ahead and get the tune.  I get the tune and it still does it, so now I know it's not the rev limiter.  I proceed to tear through everything I could think of that would cause this sort of problem. 

I found out that the EGR line from the valve cover to the intake wasn't attached, but kind of glued on (leaving an unmetered hole in the intake).  First thing, I rip that off, plug the EGR line hole in the intake and vent the tube from the valve cover to a filter.  I then start datalogging with my Torque pro app.  I put 93 octane from a reputable gas station with octane booster bottles on top, and around the same time I also got new spark plugs (gapped them lower and lower) to test that theory.  I also seafoamed it.  After all of that the full rev limiter feeling "breakup" issue I was getting went away, and I was able to get it to pull all the way to 6000 rpms.  Now it's possible I was getting this hesitation feeling then, but compared to the rev limiter issue it might not have registered as a problem (I can't remember).  The other problem was I just wanted to fix the car, and I didn't do one thing at a time to see what actually fixed the issues.  I did all of it around the same time.

Feeling better about the car I took it to the track and it ran a strong 13.6 at 102. 

The track run was last September, and I didn't drive the car too much between September and March of this year.  In between I put the downpipe on it (I do want to point out that I spoke with folks at Trifecta at the time and asked if I needed a retune and they told me it wasn't necessary because the gain is small and it wouldn't cause any issues).  I get the downpipe put on and looking for any problems with the car I'm driving around and feel (what feels to me like) a hesitation above 5200rpms or so.  It sort of lets up some, but continues to pull after until redline.  I pulled out my torque pro app and have logged and logged looking for misfire events or leaning out of fuel or really high instances of KR, but I don't see anything that corresponds to the "hesitation" feeling I feel.  There is no backfiring, and my plugs don't show signs of detonation.  The one thing the logs do show is that at 5000rpms and up the afr goes from 11.9 to a low of 11.  To me, that seems to be really rich, and, I guess, could possibly be part of what I'm feeling in the "let up" of the cars powerband that feels to me like it's hesitating.  The spark plugs I put in it were NGKs originally, so three weeks ago I got the AC Delco 108s and gapped them down to .28 now verified and also changed the air filter to a brand new ac delco one.  Right after I made those changes I took the car out, logged and tested it and swear I remember the "let up" feeling happening.  Three weeks later I take it out and on the way to work I don't feel the "let up" feeling.  On the way home I didn't get a chance really to test it again.  I need to keep testing and logging to ensure, but I'm assuming those weren't the issues.     


My other issue (and the things that frustrates me) is that I don't have a garage and ordinances say that I can't work on my car in the driveway of the house I own!!!!  That means I can't even jack the car up.  I am planning on taking the car to a mechanic that is pretty smart with these cars to have him check the intercooler piping, intercooler.  I might have him put t-bolt clamps on everything.  Beyond that, I'm still leaning towards something stupid like the evap purge solenoid, or something along those lines.  I might also seafoam it again, which doesn't really hurt anything but will keep the valves clean.

Oh, also.  My plan was to first take the car to the drag strip with just the Trifecta budget tune (which I did) and ran that 13.6, and then take it back with the new downpipe.  After that I was going to pay the $400 to do the e47 tune and get track times with that.  That's another reason why I really don't want to pay Trifecta to do the custom tune (if it won't fix anything) only to have to pay an additional $400 for the e47. 

That basically brings us up to this point.     

[JoshMcMadMac]

MattM, I have an HPTuner interface and am relatively local. It's unlocked for the 2009 Sky, but I don't think you have that year? Either way, if you are interested you can borrow it or I'll sell it to you. I gave up the Kappa over two years ago now and really need to start clearing some of this stuff out.

[MattM]

MattM, I have an HPTuner interface and am relatively local. It's unlocked for the 2009 Sky, but I don't think you have that year? Either way, if you are interested you can borrow it or I'll sell it to you. I gave up the Kappa over two years ago now and really need to start clearing some of this stuff out.

Thanks, I have a 2007 though. 

[Uranium-238]

Thanks, I have a 2007 though. 

You can still data log, even without the license for that model year.

Any serious engine troubleshooting and you need HP Tuners, in fact reading through your post on the history of your car, my knee-jerk reaction was you should have bought HP Tuners instead of the Trifecta tune. IMO, even if you run a canned tune you should have HP Tuners (or something with similar insight into the ECM) in order to troubleshoot issues that will inevitably arise.

[Sol Asylum]

And you can buy the credits to use it on an 07.

[Steelmesh]

Trifecta business model is pretty good (in a profit sense), lock out the ECU so customers are forced to stay with Trifecta.  Then it's a hassle and cost to go away from Trifecta, Matt and others alike are invested into the company.  With HPT you can work with many different tuners or just tune it yourself; but people have to re-invest getting their ECU unlocked or a new ECU programmed then buy the HPT hardware and credits.

[MattM]

Trifecta business model is pretty good (in a profit sense), lock out the ECU so customers are forced to stay with Trifecta.  Then it's a hassle and cost to go away from Trifecta, Matt and others alike are invested into the company.  With HPT you can work with many different tuners or just tune it yourself; but people have to re-invest getting their ECU unlocked or a new ECU programmed then buy the HPT hardware and credits.

So true! Beyond that though....They definitely give decent tunes from Trifecta, and for the most part they are safe tunes!

So a quick update.....I had to drive the car today to work, and I decided I would test it again....That "hesitation" feeling wasn't really there again, or at least it was much "milder."  I sort of felt maybe the powerband let up slightly around 5100rpms but not as drastic as a miss then pull again to redline. 

I'm almost thinking maybe it's not even engine related whatsoever!  I mean, you guys now this car much better than I do...Is there a chance something with the ABS system is causing them to add a slight brake at that RPM?  It would have to be RPM related though.

[Uranium-238]

I'd blame traction control or stability control prior to thinking ABS. Traction control hits like a hammer in the Camaro, I don't run with it on for fear of damaging an axle.

What's the weather like today compared with when you last noticed this issue? Here in MD its a nice cool dry day, could be something IAT related.

[MattM]

I'd blame traction control or stability control prior to thinking ABS. Traction control hits like a hammer in the Camaro, I don't run with it on for fear of damaging an axle.

What's the weather like today compared with when you last noticed this issue? Here in MD its a nice cool dry day, could be something IAT related.

Hmmmm....I do have to put it in competitive mode for the tune to work.  I was thinking weather too, but the last time I took it out and didn't have a problem it was 85 in the morning and humid.  This morning it was 65-70 and dry, and still no problem. 

The IAT suggestion is also something I'm looking at.  Id did notice on my datalogs that with an extended run my IATs were jumping up to about 120-130 degrees (from 2nd until 4th).  I did test that today again by doing a WOT pull into 4th through the entire power band.  That definitely has it boosting enough to pump those IATs up.  Unfortunately I was running late for work so I couldn't start a datalog.  I'll do one on the way home today though to check the IATs.

[elff]

I'd take up Josh's offer for HP Tuner's 
Since you only need it for logging, you do not have to buy credits.
It can really help a ton as you can log a bunch of information.

It eliminates a lot of guess work.
and
you can then take screenshots, and or upload the logs so others can look at it in more detail.
There is nothing like seeing what the car is doing at the time you feel it.

@steelmesh  Your comments are why I don't like Trifecta's tuning.  Even if I don't do the tuning myself, I want to be able to compare the tuner's changes to the stock tune.