Mis-matched combo w/ e38 barely running, need some ideas!!

[Nate007]

We've got a customer project that we're supposed to be sending home in a day or so, and are having a few issues, hope somebody has some suggestions.. Sorry for the long explanation, but this is a bit of a confusing mess....

We've got an '08 6.0 from a wrecked 2500HD (L96?) that we've had sitting around our shop for quite some time, and decided to sell it. Ended up with a customer job to install it into a 1971 K10. (4x4 short bed). We've also added Vintage Air, Dakota Digital VHX gauges, and have added electric fans. Fuel pump is a Walbro 255 with a Corvette filter. Pretty standard swap stuff.

To keep this from becoming a novel, I'll just say that this motor had a chopped up harness (missing connectors all over) and was missing throttle body, MAF, 02's, and most of the front accessories when we bought it. We didn't care because it was extremely low miles and a price we couldn't say no to. We bought it for our '91 S10 2wd Blazer shop truck, and was to get a 2.8 KB, cam (VVT delete) etc and controlled by a Holley Dominator ecu. Now it's a customer project and mostly stock except for a cam swap (VVT delete). (Specs are at the shop - I can't remember exactly what they are)

The original 6L90 we got with the motor when we bought it had a broken bellhousing from the accident. We were unable to find a suitable transfer case for a RH drive front axle given it's 34 spline output, so we bought a 6L80 from a '13 Camaro that was being built by another local shop. We had it gone through and converted to a 4wd, added an NP208 and installed it.

We didn't have any problems with licensing or being able to edit the file(s), but the ecu we bought ended up being from a '10 GMC 6.0/A6, So now we have an '08 motor, a '13 transmission, and '84 transfer case all assembled in a '71 truck. We picked up a used throttle body from another local shop and ordered a throttle pedal for an '08 Silverado from our local parts supplier. Pretty normal day for us really.. Now for the issues...

1. We did struggle to start it at first, mainly because we figured out the MAF is junk. It reads 12,500 hz at idle, so we've got a new one coming in the morning. Just to mess around with it and try to get it to not sputter and run on just a few cylinders, I multiplied the entire MAF table by .10 and it would then start and run surprisingly good..

2. The throttle pedal also worked just fine when we first turned the key on, but... It would operate the throttle body and had full range of motion with the key on/ engine off, however immediately after starting it the throttle position would stick st 33% and the engine would start surging and eventually stall. One time I was able to start it, and rev the engine a couple times with the pedal , but then it wen't right back to crap. I'm sure the REP mode is something in the tune, but I'm concerned that we'll fight this due to the mis-matched years of all the components??

3. My main concern with all this it that through all of the stuff we went through to get it running, the check engine light was on in the Dakota Digital dash/display. I could use the VCM controls to turn the light off, but it would come right back on. The really strange thing though was that it would NOT pull any DTC's?? It wouldn't even highlight the boxes in that window as it ran it's checks and was completely unresponsive. Not sure what gives with this, does anyone have any ideas? I'm pretty sure that if I could get this thing to read the DTC's, we can work through the issues one by one..

I'm looking to see if anyone knows of any compatibility issues between the '10 e38 and a '13 6l80 w/ an '08 6.0 (stock & original intake/injectors and MAP) Could any of this be the problem? It does work, just not very well yet..

We do also have a 100 ohm resistor across the #6 & #14 pins (LAN+ & -) on the back of the DLC. I've read that it needs a 120ohm, but I've got either a 100 or a 150, and our local Radio Shack closed a couple months ago. Should have an assortment delivered tomorrow, but I'm doubting that's the problem..

Thank you in advance for any help! Hope to send this thing home in the next day or so if we can get it tuned/working right..

[brawls43]

Was the throttle pedal with the original engine? I'm in to hear any answers, as I'm tracking similar issues with an L76 6.0L. I've seen some stuff posted about OS's but haven't seen a straight answer. Might be an issue with the '13 trans controller vs the '10 ecm, but I don't know. Could check the repository and see if some of the base settings need to change to match? Definitely don't flash an '08 file to the '10 ecm, I've read that's bad with the e38's. Hope to hear about an answer.

[Nate007]

No, the pedal was a Standard brand service part from our auto supply warehouse.
We've actually gotten the truck to run, and are sorting out small startup to idle transition issues while finishing up putting the truck back together so we can actually drive it..
The REP issue was due to a MAF issue. It was looging idle hz in the 14,500 range with airflow readings between 7-10.. Replaced the MAF, everything worked great..
We anticipated issues with the compatibility of the different years, but we compared nearly every '07, '08, '09 and '10 tune we could as well as the few that we've tuned before, and started copying differences to the '10 ecu. Did one write entire to remove the securities, and that was it. Haven't had any issue with copying the calibration(s) from most other years. It seemed that there were a few things that wouldn't copy over, but for the most part, it worked just fine.
I'm not experienced with tuning to be as confident as I'd like, but I'd like to think I'm enough to be dangerous.. I'm not sure if the people who experienced issues flashing a "file" from an '08 were doing it differently than I am, but all I do is copy calibration settings/table adjustments from other years, and the ecu/TCM still has their same OS's. Other than going in and editing myself, I mainly use the repository for calibration "suggestions". Seems to have worked fine for me so far, although I think we've only got 12-13 licenses so far..
We do have a MAP voltage issue with a P0108, so we may have to swap that as well. All the wiring tested fine, so that's the next replacement.. Not sure if something is wonky with the sensor, or if there's a setting we can try to adjust to rule out the issue/narrow down the problem?

Only thing I've noticed is that with the key on, engine OFF, there is a faint high pitched whine that seems to be coming from the TCM? Has anyone heard this before? It stops briefly when the editor switches to a TCM erase/write, then it comes back after. Is that anything to be concerned about?