Noob. Trying to get running without tuning.

Hi All.

I swapped a LY6 and 4L80e into a 1976 Winnebago (I saw Turbo LS Swap on youtube and couldn't resist - just all stock still though).

Anyway, engine and trans combo were purchased together (but were not from the same vehicle; eng from Yukon, trans from ??). It cam with standalone eng harness and computer (e38-12614088), and matched trans harness and tcm (t42-24235341). The harness had no knock sensors or O2 sensors, and VVT was tuned out (I believe for a hotrod) - I added the wiring for the knock sensors, primary O2 sensors, and VVT since I was hoping to be more stock (the Winnebago is no hotrod - yet). The engine starts and runs well sitting and revving (although a little looping at idle but strong on the throttle - the MAF sensor is not calibrated I think), but when rolling it goes slow then coughs and stalls abruptly, but if I quickly shift to neutral before it stalls it stays running. Attachment 109797 Attachment 109800

I have been scouring local junkyard for an LY6/MT1 e38/t42 combo (2008 Savana/Express). I found one but they would not give me the t42 without me also buying the transmission. I took the LY6 e38-12617631. I also tracked down another can (also 2008 Savana/Express) with an 6.6L diesel and an MN8 (4l85e) - so I grabbed the t42-24239927. I connected them to the Winnebago wiring and pulled the tunes as a combo. Attachment 109798

I also tripped over another van (also a 2008 Savana/Express) with an LY2/MT1 that had e38-12617631 and t42-24239927 as their combo (same OS's 0 I am not sure if that is a coincidence. I also connected them to the Winnebago wiring and pulled the tune. Attachment 109799

The Winnebago would not start with either the LY6 computer or the LY2 computer. VATS???

I plugged the MN8 computer in with the hotrod computer, but it wouldn't idle enough to idle in gear.

I was hoping to connect the LY6 computer I picked up with the MN8 computer and drive to a pro-tuner (or peraps the LY6 with the MT1 computer). But maybe using the LY2/MT1 computers together (since they are from the same van) is better then tuning it to run. Would the LY2 computer run the LY6?

Sorry for the long post, I have spent a hundred hours cruising the posts, and at least that many cruising the junk yards. I am hoping I am close.

Thought's?

Thanks
Roger

One of the o2 sensors still isn't working in that log. The ethanol content is stuck at 38% too. if you aren't running a blend of E85 fuel you need to disable the flex fuel feature and put the stoich at 14.2ish for regular E10 fuel at the pump.

VATS is still enabled on that first tune file posted, that would need to be turned off to let it start and run.

You will have to go back into that computer and turn on things and turn off things still. All the o2 sensor codes for the front sensors need to be turned on again. VVT is off in that first tune etc etc.

Sometimes it may be best to find a stock tune like you already have and just do a copy/paste to make it all stock again and then do the changes you need. Like turning off rear o2 sensors, cat codes, cat test, rear o2 sensor test and any other sensor it's not running.

Interesting. I could see lots of that, but it seems pretty far the wrong way for running as a stock engine/trans. (regular 87 octane fuel, O2 management, VVT, etc.)

Could I use the LY6/MN8 controllers from different vehicles together? Or would it be better to use the LY2/MT1 controllers from the same vehicle and adjust the LY2 setting to match the LY6. Or even the LY6 controller with the MT1 controller. I also downloaded a LY6/MT1 van stock tune from the repository to, but that may not be useful for me.

Can I turn of the VATS just by clicking the two tabs in the OS screen to disable (and the starter tab to disable also)? Then do a write entire across everything. I recall seeing a couple other starter tabs in other screen too - do I need to do anything with those also?

I have not licensed any of the computers yet, so I was hoping for some advice on which to do, and then the simplest possible configuration to be drivable for getting me to a pro tuner.

Thanks again
Roger

I have a bone stock 2006 lq4 tune from a Silverado/Sierra if you want it.

Thanks Mr. Guy.

I was mostly wondering which computer configuration of all the parts I have, I should license and then remove VATS in the hopes of actually having the engine and trans I have start and drive out of the gate.

I guess, specifically, will the LY6 e38 I have work and can I put the MN8 t42 I have with it, or would I need to use the LY2/MT1 e38/t42 combo pulled from the same vehicle as the start and remove VATS and configure as LY6 tune. I am likely not writing that all right, but best I can do while my knowledge develops.

I'm not the right one to answer the questions. I'm just getting started with tuning. Let me know if you would like the stock LQ4 tune for reference. It may not be what you want but it would allow you to use it as a reference to the stock set points.

Yesterday, I ended up going with the LY6 computer since I wanted to go with LY6 tune and it was the only one I could save the tune back too (I am sure I could have with the others, but it was easiest with the LY6 computer).

Step 1) I disabled just the two VATS toggles in the OS tab, uploaded the tune. The engine started right up. Bad idle thought, and not much throttle response (It wouldn't start without the VATS disabled).

Step2) I have a cold air intake, so I figured out what vehicle the MAF in the COI was from (2013, 5.3L Silverado), downloaded that tune from the repository, copied the MAF frequency vs. airflow table, and the slope and offset values to the LY6 tune. The engine still started right up again, and it idled perfect and there was good throttle response. It backfired quite a bit though.

Step3) Plugged in the MN8 controller. The transmission shifted amazing. So I was all set to move ahead with the LY6/MN8 e38/t42 combo (e38-12617631 and t42-24239927).

I drove it and ran it through several heat cycles. The backfiring went away, but there still seems to be a misfire or something. The Bank1 Sensor1 O2 sensor is pretty jumpy (very high and low) - the other side is perfectly stable. I do not know which is right, but it seems like it should be pretty stable. There are a few codes - one is for Cylinder 1 Injector Circuit (P0201), and a Random Misfire (P0300); all shown below. Can anyone shed some light on what I need to do next?

Attachment 109889

Attachment 109890

Check that the injector connector is properly connected to injector 1. If it's connected properly, check that the injector does have 12V with key on.
If everything looks good, check the injector wires. If they are intact, and have proper signal, swap the injector.

That was it. The injector (ground side) female was a bit bent. I pulled it out, pinched it a bit, and put it back together. Problem solved.

The stable O2 sensor was the working one. The other one wasn't even plugged in. I plugged it in and CL-Normal so good to go there.

Now I have an IAC glitch. If I let it sit for a bit, it starts and idles at 550. Drive it for 10 mins, then put it in park and idle is at 1500ish. It puts up DTC P0507. Does anyone have any ideas about that?

Also, how do I get it to stop looking for the second O2 sensors and the evap. (those seem to be the only regular DTCs left to iron out - for now).

The latest log is attached. Attachment 109894

B1S1 is not working, it's flatlined at 450mV. The other sensor is what a normal narrowband looks like in closed loop, it's supposed to switch from full low to full high, the computer then uses the midpoint to know where stoich is.

Click the Details tab (bottom of the Channels pane) in your log to see the codes. The B1S1 codes need to be diagnosed and fixed; if you don't have any post catalyst sensors the codes for those need to be turned off (along with the other settings to tell it there are no catalysts or downstream sensors in use). Evap codes need turned off if the hardware is not used in the swap. Once those basics are taken care of, see what the misfire situation is and diagnose whatever remains.