monte0

iTrader: (1)

I just finished up doing my swap into my 70 monte carlo a month back and I'm running into some tuning issue's that's I'm having trouble ironing out. Specs on my setup is L96 2014 motor, 08 4L80, E38 pcm/T42 tcm with a 08 2500 van file as my base file. Running the stock #50 injectors that came with the motor and vvt is disabled.

Issue's I'm running into is high idle when you let of the gas and coast, plus when you come to a stop it holds the idle and slowly comes down. And if you let off the brake and coast the idle goes right back up again. I'm a little new to the gen4 stuff so not sure what tables control that (I have no throttle cracker tables)

Second issue is when warming up the engine, when cruising steady will surge up and done a little. Can hear it in the exhaust and feel it. Once fully warmed up the issue mostly disappears but you can faintly notice it still on the expressway.

Third issue is the trans. I'm having issue's still getting the trans to do what I set in the tables for pressure. Most of the time the trans shifts ok, not great or solid like I would like to see. But every once in a while when I start it and drive down the start the trans will go full pressure slamming every gear. Only way it stops is if you cycle the engine on/off and then drive again, then things return to normal. Torque management is mostly off and shift times are at .2 with shift pressure raised a decent amount.

Any help or direction would be great, I'd love to finish up to the tune so I can take it to the track once before the snow flies this year

gmorris

Have you calibrated the MAF/VVE tables or is the tune stock? The idle issue sounds like a minimum idle air issue...I'd try lowering that 10-15% and see what happens.

monte0

iTrader: (1)

You meant VE tables right? VE is stock, maf has been tuned to -7 to 0 range. What exactly is that table called?

eaglegoat

Or he could calibrate it for what the car actually wants instead of just guessing.... dunno.

Both problems you describe could be either air/fuel or timing related or a combo of both. My bet for the idle issue would be timing. The surging is harder to nail down. Are you running open or closed loop?

monte0

iTrader: (1)

I took the stock timing table for the high octane an smoothed them out some last night, still is doing the same. (I haven't touched the low ocatne tables at all) When I watch my timing it's pretty steady. I'm pretty sure it's air/fuel related. When idling it's smooth when stopped, but as soon as you let off the brake and coast the engine rpm picks up and idles higher. On the gen3's it would be the cracker table and decay tables but on the gen4's I don't have those tables, so not sure.

subeone

iTrader: (5)

no, he meant VVE. VVE are virtual volumetric efficiency equations and are used in e38 operating systems. You need to change your OS thats why you see those issues. You can try messing with the throttle follower tables, but you need a different OS. Had this happen countless number of times.

monte0

iTrader: (1)

Well I'm very limited on what OS's I can use with my combo. e38/t42 combos need matching hardware to run my 4l80 and think 08 was the first year. What OS would you suggest? And what's the difference a new OS would help me with?

subeone

iTrader: (5)

who told you that lie? The TCM has its own OS. If you attempt to read a e38 with the TCM disconnected, the downloaded file won't have any trans parameters. The same happens if you have ANY e38 and hook up a T42 with an 80e segment, then proceed to download the file, you'll end up with the e38 OS and the 80e segment combined in the final downloaded file. I've done it in at least 20 vehicles.

You can also modify the harness for control the 80e with a 60e segmented T42.

So no, you're not limited on the OS. Just trying to give you a heads up. 1st rule if you want help is post the HPL and HPT file.

Is it cammed? is it stock? need more information. Seems like its stock, if it is, then i can assure you its an OS issue, you could find some alleviation by manipulating the idle timing tables and the area effective size of the throttle body. But it is just a bandaid.

LSX Power Tuning

iTrader: (4)

It really sounds like you just need it tuned. We tune a good number of E38/T42 LS3/4l80 swaps and use the same ECM/OS setup on all of them.

subeone

iTrader: (5)

If he didnt setup the fuel tables properly i agree with you. Bad IFR will cause a hanging idle because the torque calculations would be off. But ive had the instance of different throttle bodies having different maps and ultimately having a hanging idle. Could be, or not. Im sure though, if he uses a l96 e38 oem OS from that year along with the proper IFR, the issues would be fixed (if its stock). If not then that goes out the window and just needs a plain tune. Lol.

monte0

iTrader: (1)

I was told by psi conversions when they did my Harness and a few other people doing tuning. I do realize the ecm and tcm both have their own OS's.
Good to know info though, I'm new to the ls gen4 stuff so learning as I go.

I'd post the file but I use tunercats so I don't have a .hpt file to post. I might be able to convert it to a .bin but that's it. Motor is completely stock except headers, maf is a ls7 and gas pedal is a C6.

So by what your saying I could use my stock e38 pcm from my 2014 l96? The t42 will function correctly as long as I match the vins right?

monte0

iTrader: (1)

I'm getting close to just saying screw it and have it tuned but good places locally are few and far between. Is their a good OS for both I should get that would be better for my combo? I can contact tunercats and they are pretty good at supplying the newest osid of whatever you like

monte0

iTrader: (1)

IFR seems good. I scaled it for the #50 injectors. I'm betting your correct though since all the sensors are 2014 and tables are 2008. I did keep the oem 2014 l96 e38, I could swap that in the vehicle and get a base tune with IFR's set and see.

LSX Power Tuning

iTrader: (4)

You can't use the 2014 e38, in order to make all the swaps work you have to use ecm/Tcm combo that was in a factory vehicle. Far as I know there are no 2014 E38/T42 combos so it won't work. You can't just flash a E38 to any year.

monte0

iTrader: (1)

Ok so that's what I was saying in my earlier post about the hardware being matching.
Is their a osid that would be better on my current setup?

gmorris

When did I mention guessing there genius? I suggested trying adjusting minimum air (which probably causes 80% of the idle issues on gen 4's) to see if it helps. He doesn't sound experienced so I gave him a value to try first.

monte0

iTrader: (1)

Did some more checking and found my surging issue. I noticed when the car came to a stop and idled for a few minutes,the trans would engage something quick while sitting. (Felt like the car got pushed from the rear) Had a gut feeling it was the TCC so disabled any engagement completely and the surging disappeared.
Drives much better and rpms are steady now.
So I noticed in my tables a setting for max TCC limit torque was set to 0 stock. From what I can make sense of this 0 means no torque is allowed to TCC. When I compared to one of my other 4l80 files the setting was maxed out to 6042. I'm guessing the maxed out setting means its disabled and 0 means it's not letting the TCC engage. Any thoughts?


Also on a side note separate from the TCC is the maf readings while driving. I'm using a LS7 card style maf and have a diverter screen in front of it. I've noticed up to 200-300 hz fluctuation of the maf while driving steady. I have read on other sites of people having similar issue's and having to put a second diverter screen after the maf too to keep turbulence down. Any thoughts on this too?

eaglegoat

When you randomly pulled 10-15% out of your butt, genius. Sure glad you're here to make up random statistics and suggest random values to use.

monte0

iTrader: (1)

I narrowed it down the idle issue to my adaptive idle control. THe speed for it is set to 1.2mph and that's exactly when the motor rpm picks up. What tables are related to the adaptive idle enable?


Also like I mentioned in my last post, anyone have any ideas on this?

"Did some more checking and found my surging issue. I noticed when the car came to a stop and idled for a few minutes,the trans would engage something quick while sitting. (Felt like the car got pushed from the rear) Had a gut feeling it was the TCC so disabled any engagement completely and the surging disappeared.
Drives much better and rpms are steady now.
So I noticed in my tables a setting for max TCC limit torque was set to 0 stock. From what I can make sense of this 0 means no torque is allowed to TCC. When I compared to one of my other 4l80 files the setting was maxed out to 6042. I'm guessing the maxed out setting means its disabled and 0 means it's not letting the TCC engage. Any thoughts?

Also on a side note separate from the TCC is the maf readings while driving. I'm using a LS7 card style maf and have a diverter screen in front of it. I've noticed up to 200-300 hz fluctuation of the maf while driving steady. I have read on other sites of people having similar issue's and having to put a second diverter screen after the maf too to keep turbulence down. Any thoughts on this too?"

subeone

iTrader: (5)

Set the top value and bottom value to 120 mph and see what it does on that adaptive idle entries. It should alleviate the issue. But merely a bandaid.