2012 ctsv negative timing at idle and just off idle

[ctsvpharmd]

Hey guys I was hoping I could get some help here. I have a 2012 ctsv 6 speed coupe. On e85, brian tooley/weaponX stage 3/track sweeper cam dual titanium springs, hardened push rods, tit. Retainers, seats and locks, 2.4 upper sc pulley 8.6 lower, id 850cc injectors, kb. Boost a pump, airaid intake, ported tb and sc snout, sc lid spacer, stainless works. Headers and catless x pipe to stock muffs w/ cut outs, weapon x track attack heat xchanger, norcal expansion tank, high flow heat exchanger pump, custom adv.1 rims with mt et street 2s on the rear slightly larger than factory roklibg diameter, 1 step colder plugs, msd wires, lingenfelter launch control box, eibach sport springs, d3 sway bars 160 degree tstat.

Ok here is my crazy issue.
After abiut 1 to 2 hours of spirited driving the starts to pull timing dramatically at idle so that I actually see negative timing numnbers. The car then seems to randomly misfire and pop at idle. The exhaust note is less full and sounds weak. Then upon acceleration the car still has very little timing and chugs as if im only firing 4. Cylinders ir running into a slight rev limiter. This happens regardless of tuning style. Maf only, speed density, blended speed density, open or closed loop fueling. We have changed the plugs....still happened eventually. Went open loop just in case it was bad o2s...still happened eventually. The last time this happened something started comanding like 38% throttle at idle. Changed the tb. This made that go away it has still fallen into that neg. Timing at idle deal but the just off throttle chuging is less severe. It sounds like a Harley. ...chop chopp chop...the exhaust notes are seperated a lot more...less exotic sounding....llike a beater runing with open headers. Thought mayve the lingenfelter box so disconnected it and it made no difference. Totally puzzled.
Help! I have iver 100k in this car included in its price and want it to run well.
Thanks for any and akk help
-Mike

[SultanHassanMasTuning]

post your file, so we can see whats going on. and a log would be great!

[ctsvpharmd]

Ok will do. Tonight night after work. I live right next to injector dynamics. I spoke with one of the engineers randomly at a car wash...he said they have had a few issues with the 850s overheating, then leaking. From the symptoms he described this makes sense. Ill post after 10pm tonight
Thanks for the help.

[Badassbird]

Every time I have seen this it has been due to an aftermarket TB.

[SultanHassanMasTuning]

^not properly calibrated? or just giving fault signals?

[Badassbird]

I have tried recalibration and had limited success. Usually replacing the TB is the fix. Common problem with the TPIS TB.

[ctsvpharmd]

We put a stock tb back on and at first it was less severe but eventually decayed to chug a lug mode. Been in direct contact with ID said they have had some overheating and subsequent leaking issues with their 850cc injectors. We logged it and 1 bank has gnarly fuel trims as if feul is dripping into the cylinder, thus not combusting O2 sees tuns if un combusted O2 thinks its lean fuel trims rise car goes to chopper style. Im not sure how too post them from my phone but ill give it. A shot

[DSteck]

I saw the tune from your vehicle. You SEVERELY need it redone by a professional that knows what they are doing. Your idle issue is due to trying to run excessive timing and airflow at idle.

Leaking injectors are not something that make issues surface while running. Leaking injectors cause engine start issues. I just wanted to clear that up.

[ElecTech]

Sounds like an air leak to me. The negative timing is trying to compensate for a high idle air, either that, or a misfire causing the trims.

If you are right next to them, take the injectors out and let ID test them for you. That will put that theory to rest.

[ctsvpharmd]

I saw the tune from your vehicle. You SEVERELY need it redone by a professional that knows what they are doing. Your idle issue is due to trying to run excessive timing and airflow at idle.

Leaking injectors are not something that make issues surface while running. Leaking injectors cause engine start issues. I just wanted to clear that up.

Mr. Steck I appreciate your input, I do have huge start up issues as well. I have also loaded previous tunes from other big names around dallas.
While the off idle acceleration and idle were the issues you had, we took your suggestions and the car literally wouldnt run, well would not hold idle at all..falls on its face and stalls. The base idle air flow of 2.7grams or something like that(dont even know if Im referring to the correct value or term) is some 2 or 3 times what other cts-v typically require this seems odd to all of us working on the car. Everything we have changed seems to help for a while then back to thomas the train air compressor mode. The tune that you saw believe it or not ran perfect, did not hang idle when decelling or during clutch application. We have changed plugs, 02s, throttle bodies(at one random point when the car was the worst my ported tb was being commanded to stay at almost 40% at idle). Put a stock one back in and it helped a bit. The odd thing is that it comes and goes and above around 2000rpm in runs smooth as buttuh, no flat spots air fuel is dead on and 0 knock. At idle and just off of idle if getting off the clutch bellow around 800 rpms is when this issue is the worst and it is clearly misfiring the entire time it is chugging. Changed out the injectors last night for some 1300 and it seemed to help, but before it was the worst after sitting for more than about 4-5 hours. if it sat for 8...it was a cross my fingers lets hope this SOB starts. Ill find out if this truely made a difference in a bit when I start it for the first time in 8hrs
The intermittentcy(not really a word) of the whole issue is what drives me crazy. We have tried 5 different tunes and 2 differnet tuners. Maf only (open and closed loop) pure speed density from scratch(took hours to build given the hundreds of tables) blended speed density and maf (open and closed loop). the tuner working on it now has done hundreds of ls cars and 10-20 Vs...some with nearly double the power of mine and has never had an issue but has fixed many issues from other tuners. The tune you saw was all done to make the car run well...i think I have a unicorn.
I have the first lingenfelter 2 step ever on an lsa cts-v my norcal ice box sits right over the passenger side igntion harness where the 2 step Ts in...it gets leaked on as well as the ecu heat sink also located directly bellow the ice box. The ice box will spew coolant once in a while if over filled due to ice. Im really clueless now as to what it could be. Im thinking maybe a short in the wiring harness clip from coolant corrosion, or plugs bad again (I run e85 and am not sure if this is extra stressful on plugs).
Once again thank you for all your input it is much appreciated and any further input is greatly appreciated as well. Please dont think your suggestions were not taken into consideration as we went thru last night and changed nearly everything you suggested. I think it is a spark issue or leak somewhere. And the tuning is going wild trying to compensate!
Best Regards, Mike

[ctsvpharmd]

Hey Jaime, we changed the inj to 1300s last night and it helped a bit but it still has issues. It is def misfiring at idle and jsut off of idle when accelerating starting bellow 900rpms...this is all only when the problem is present. It is intermittent. Once above about 1500rpms out of first gear when this issue is happening...it stops, the car runs perfect above this and when wot, airfuel(lamda rather) is dead on, 0 knock and zero flat spots. Im at a loss of words at this point.

[DSteck]

Good luck.

[ctsvpharmd]

mikes emailable tune.hptmike log 4.hplOk fellas here is the log and tune. I think about 10min into the log you will see the issue start to occur. Keep i mind this tune runs well makes good power and really has no drivablity or idle issues...until this stupid problem precipitates. The issue does not only occur with the tune posted. It occurs with the 4 previous tunes one of which is from a pretty well known shop in the dallas ft worth area, the tuner has 15+ yrs of experience and teaches for HP tuners...this issue occurs with his tune and the other tuner whos tune will be in the post...It is clearly misfiring when sputtering at low rps and at idle its a bit tough to see on the narrow bands but is noticable

[ctsvpharmd]

Thanks! Just hope there are no holes in my pistons. The thing I hate about tuning is there is 10 different things that could cause the same issue or 10 differnet ways to get the same thing accomplished. In my profession there is 1 f***** way to do things...that is the right way, all other ways have been discounted with 10-15yrs of studies. Cars are far less difficult to study and diagnose than humans seems like there should be some software by now that could run complete all inclusive diagnostics on a tune and mechanics of a car that could pin point ones exact problem. Trillions would be made!
Take-er easy

[ctsvpharmd]

Just posted sorry for the delay CVS be keepin a cracker down

[turbomystic]

Post your file please.....I have same set up with id850....I will try e85 tomorrow and want to compare against your tune file

[Pulse_GTO]

Find a fix?

[MStefak]

Humor me and take the Spark > Advance > Spark Ramp Out > Spark minimum table and put your main spark table in it .

[youngsmab]

gm had a recall/tsb on the cts-v hose clamp rubs on main engine harness would cause drivability problems

[Speedmaster747]

I had a Trailblazer SS a few weeks ago that was idling on -13 degrees of timing, it made the headers glow red....
Commanded idle was about 800 rpm and it was sitting at 900+ rpm. The truck had a LS7 ported throttle body, I doubt it was done professionally since it looked uneven.
I did some adjustments to the Throttle scalar and idle went back down to normal, timing went back to normal and no more glowing headers...