need MAJOR COMPUTER HELP - LS3 in speed density

[cdoggy81]

Hi guys,
I am in need of any tips or ideas as to how & proceed with this one as it has a lot of people stumped....

Everything started off as the following:
LS3 swap out of a 2008 Corvette into an old Trans Am.
Stand alone wiring harness from Current Performance, E38 computer & TCM to control the 4l80e tranny
2008 Corvette Operating System was loaded - OS & base files, Vats removed, no MAF, will be run in Speed Density (SD).
87mm CTS-V / Truck throttle body on top of a Holley Single Plane intake (this is to keep the look & functional shaker for the Trans Am as seen below).
Engine mods are: BTR cam 225/238 .612"/.585" 113+3, Ported WCC heads, 1 7/8" headers, 2.5" exhaust, no cats.

Car started up pretty easy at the builders for the first time with no major issues, just pig rich so all we did was drive it around the complex a bit to make sure everything was working properly & mechanically safe to take it to get tuned. Got the car in to the tuner finally & was able to to start the process. We get all the basic parameters adjusted, set it to fail the MAF on startup & started working the SD tables. Started right up after the re-flash & even idled better so we took it for a run to start filling in the tables. Got back to the shop to load some more info & she would not start again after turning it off. After a lot of back & forth (thinking it was a fuel pump, maybe wiring or a bad ground, bad computer, etc.) we determined that the corvette OS did not like the fact that we had an 87mm truck TB on there vs the stock 90mm corvette one. When I got her back home on the trailer & the next day put the stock corvette TB back on the problem was solved. Started up every time, idled good, drove around good (nothing fast or hard).

Brought the car back to the tuner & he loaded a truck OS overtop of the corvette so it would now work with that TB but as my luck goes it bricked the computer.... :l So now I have to buy a new e38 computer from the dealer & have it all setup from the start for a 2012 Silverado. At least we now have a clean slate & correct base OS to work from.

Back at the tuner everything is working good with the new e38 & base OS, it is taking all the changes & file adjustments he is throwing at it in HP Tuners. All is looking good until we start doing wide open pulls. When we go WOT the car goes into protect mode every time. We reset everything & try it again but this time by rolling into the throttle & it seems like once you hit a certain RPM (say 4500+) or throttle position (like 2/3 open +) it goes into protect mode. Tuner asks out of the blue if the TB has been modified bc sometimes over ported ones cause problems. Sure enough I said yes this is a ported TB out of a CTS-V. He said that maybe causing the problem so we decide to buy a brand new 87mm truck TB for the 2012 Silverado just to be safe as it should fix the issue... :l

TB comes in & a few days later I am back at the tuners. We put the new TB on., she starts right up, we take it out to start tuning again & same issue, limp mode at WOT!!! It didn't fix anything.

Does anyone have any ideas as to what could be causing it to go into protect mode? What are we missing as I am at the end of my my rope here... Thank you all very much for any help or direction!

[cdoggy81]

Here are some pics so you have a better understanding of the setup, why SD & no MAF plus why I had to use the compact 87mm TB vs the 90mm corvette one (won’t fit under an air cleaner).
Thanks

[icemanrd19]

4th gear pulls above 4500 rpms I was tripping a p2135 and another code. One of my wires in the throttle body grounded out. What code are you tripping?

[cdoggy81]

IDK as I do not have access to the tuners info or computer but I can ask him.
We did however check all of the wiring the first time we had issues (before we figured out the TB issue) & it all was good. This electrical stuff is so hard to diagnose

[joeko23]

DM andrewb70 he’s on here a lot I’m surprised he hasn’t chimed in on this. He’s highly recommended on here.

[SSLance]

Andrew is on a road trip for next couple of days I believe.

[cdoggy81]

Andrew the moderator with the 70 GTO? Yes he is pretty knowledgeable with this stuff & hopefully may have a tip for me. There was also a professional tuner out of Orlando I think that was pretty active back in the day as well but I forget his name.
Thanks to all who have or may have ANY tips for me on this one. This is costing a ton & causing me a huge headache for something that was to be such an enjoyment after so many years of building ;(

[btmatt]

I need an air cleaner adapter just like that. Mind sharing where it came from?

Thanks, Matt

[cdoggy81]

Custom made, a day on the mill & lathe at the shop.
Delmos has a nice one though & if I were to buy one I would get theirs.

https://www.delmospeed.com/product/t...y-adapter-ls3/

LS Classics has one too but not sure if you can just buy that solo.

[icemanrd19]

Without the code we are only guessing. Start it and drive until the check engine light comes on and then let us know.

[cdoggy81]

I have speed hut gauges so no way to check the code unless someone can hook up a scanner. Hopefully the tuner has a log & can look up what the code was. I sent him another follow up just now so hopefully I will hear something back...

[cdoggy81]

I did just hear back from the tuner & another reason this is so frustrating is bc it is not throwing any DTC's!
We are going to go back through & verify the entire OS did in fact make it onto the PCM.
Also airflow limits are maxed as airflow diagnostics are disabled when he does a new camshaft tune.

[Bad Bowtie]

There was also a professional tuner out of Orlando I think that was pretty active back in the day as well but I forget his name.;(

No longer in Orlando,
http://www.mikenorrismotorsports.com/

BB

[KnightmareZ]

Sounds like your airflow is exceeding the stock parameters set by GM. GM sets, as a safety precaution, a max amount of airflow, based on tps and rpm. Exceed this value and it goes into limp mode.
Tell your tuner to check under engine diag/ calc airmass- P1514/P0068 error
This needs to be scaled up to compensate for the additional airflow from the heads and cam.

[andrewb70]

Sorry for the late response.

Sadly, I do not do any OE system tuning. I only do Holley EFI tuning. If you had a Terminator X Max I would be happy to help. You have a super cool setup and I know the Holley would not have these issues.

Andrew