I will PAY YOU if you can tell me whats wrong with my car before I drive it off a cliff

* My current tuner is awesome and am not saying anything against his name, he's doing a great job, im just asking for some outside help. Maybe someone else has had this same issue?


I am so angry that I have typed this about 500 times. I am not angry at anyone in-particular just with this car and the overall process.
I wont say what isn't wrong with the car because I don't even know what is wrong with it, and neither does anyone else. What I can say is this:

• My engine has been rebuilt within the last 1000 miles.
• As far as I know and tuner number 2 knows, my car has no mechanical issues.
• Tuner number 1 wanted me to replace my Comp Cams with factory cams because he thought but wasn't sure, that I degreed my cams wrong.
• He thought this because his tune has about 20* of timing around the high idle he gave me of 1200 rpm
• Tuner number 2 provided me with a base tune and a few adjustments that had timing at 0.00 at idle and it purrred like a ****ing COBRA KITTEN.
• This made me and everyone else think that if it truly was a cam timing issue, by this point, it would have bent a valve and broken my soul beyond repair

I have replaced the following parts during this whole tuning process:

• Upstream o2's
• TR6 plugs @ .028
• Oil & Filter
• FRPS
• Oil Catch Can

Latest tune process as follows:

My initial WOT 3rd gear pull (30mph to redline)
AFRS 12-12.5 range
one upstream sensor was disabled (for exhaust balance issues)

2nd WOT 3rd gear pull (30mph to redline)
Major hesitation at low rpm (did not exist in prior tune)
AFR's went to 10.0
STFT bank 1 and 2 went opposite of eachother until WOT run at which point they went to 1.03 and 1.05.
At idle after my WOT run Bank1STFT 1.3 Bank2STFT .88

Now i asked if he had turned on both o2 sensors in the revised tune and he said the following
"No, the only change between that and the last was just WOT fueling, something else had to be going on.
I took out 4% out at 550MAF counts on up, should lean it out to perfection.
The log at 200 maf counts, the o2 sensor removed 28% fuel and still didnt switch. It was perfect before at 200 maf counts, no reason why it shouldnt be now."

he sent a revised tune and it acted even worst with my STFT on bank 1 going to 1.99 and then bank 2s in the 1.08 area. When I get on it they both go to around 1.03 but then afterwords they do what they want and bank 1 skyrockets again.
I replaced the FRPS and now the STFT are a little closer, but it still bogs out and takes fuel out for whatever reason.

CAN ANYONE help figure out WHY it would remove fuel? Why a tune would work one day, the next it runs like shit?

I have a VMP GEN1 blower that used to be at 19psi now at wot its only around 15psi. so not sure what thats all about.
SCT BA3000
Fore everything, return style, dual gt pumps (running full time)
63# injectors
EGR delete
DSS GSX forged pistons 8.23:1
Comp STAGE 3 cams (beehive springs etc)
ARP studs, bolts you name it
Canton pan with windage tray
etc etc etc

Low compression motor, there should be no valve piston contact.
Just my guess and few hours work to double check, vacuum leak. Pull the intake/blower new gaskets.
Sounds like a headache, keep us posted.

So pull the intake, blower and new gaskets?
Can you tell me why either of those items would signal the upstream sensors to pull 28% of fuel?

What fuel ?
who's injectors ?
i'd dump the TR6 and go 7's

Fuel is 91 (all this state can do) DEKA injectors.

WOT your car is in open loop, which is why they’re reading differently. Obviously some major issues if it’s trying to pull that much fuel. Injectors are recently cleaned? What injectors are you running (I see the 63#, I mean specifically)

I wonder if something is corrupt in the tune. When you go WOT the STFT should reflect whatever commanded lambda is. Like for my car it's .78. So anytime I enter open loop the STFT's show .78 on the datalog. At which point I'm looking at the wideband reading.

IMO this isn't a plug or hardware issue. It's a setting somewhere in the tune.

it's just The tune.

Sent from my SM-G930V using Tapatalk

The tuner who’s currently doing it now is a reputable member of this forum, and he was taken back by what the car is doing. The injectors are DEKA and have been clean and serviced last month.

the previous tuner was a brick and mortar shop, with both the shop and the tuner having a outstanding rep with mod motors.

I can post data logs if you guys want to take a look.

honestly, could it be the VMP? ECU?

So did you have this issue with Tuner #1 as well? If not, why did you switch to Tuner #2?

if the cam timing is off any noteworthy amount wouldnt you see a compression variance bank to bank? Might be worth doing a compression check just to cross that off the list

the boost fall off when everything else remained constant would have me worried. you may have a pressure leak somewhere. injectors may be a problem too.

I'm also interested to know why you changed tuners

Have you confirmed the t/b is opening completely?

Tuner number one couldn’t figure out why it ran amazing the night before only to Fall on its face the next morning.

The injectors were cleaned and serviced less than 100 miles ago.

TB opens all the way as well.

Also to note, tuner 1 was able to get it to run rather great but only in open loop and shutting off the o2s.

maybe you have an issue with the o2's? from what you're saying it sounds like it's leading to that

Since then the o2s were replaced with brand new ones, now with less than 20 miles on them . The issue continues

Interesting. I do know that o2's can cause a lot of problems, especially in tuning. That's why most tuners just turn them off (or did)

Just my thoughts on things....

If it were a mechanical issue such as cam or cam timing the issue would be constant. It wouldn't run fine one time, then run like crap another time. Although that being said, I did have a mechanical issue that caused weird problems. My crank bolt on my old set up wasn't torqued properly. So it allowed the timing wheel to move around. When I pulled it apart the notch for the crank key was about a 1/2" wide. Which explained why sometimes the car would drive fine and other times would knock really bad. But my fuel trims were usually good. Even with 80lb injectors.