8.1 dbc conversion help

[94heritage]

So Ive recently swapped an 8.1 into my 86 c30. It originally had a 6.0 4l80 combo. Ive got the truck running good on the 8.1 avalanche file but Im not getting any actual iac counts but I get desired iac counts. I cant get it to go into an idle routine when its warmed up and it?s pulling spark down to like 5 degrees to get idle down to where it needs to be. So I did some reading on here and found a couple threads saying that I need to use a dbc os and transfer all of my 8.1 tables to that file. So I used the original stock file from my 6.0 80e combo and transferred everything over using a template of the 8.1 file that was running good. I now have actual and desired iac counts but the truck will not stay running. It fires up and runs for about 10 seconds if you hold the throttle open but then it dies. I made sure that vats is off and all the normal stuff you would think of. If I do a write entire and flash the original 8.1 file back in it fires and runs perfectly. Im lost does anyone have any tips.

[Fast4.7]

So Ive recently swapped an 8.1 into my 86 c30. It originally had a 6.0 4l80 combo. Ive got the truck running good on the 8.1 avalanche file but Im not getting any actual iac counts but I get desired iac counts. I cant get it to go into an idle routine when its warmed up and it?s pulling spark down to like 5 degrees to get idle down to where it needs to be. So I did some reading on here and found a couple threads saying that I need to use a dbc os and transfer all of my 8.1 tables to that file. So I used the original stock file from my 6.0 80e combo and transferred everything over using a template of the 8.1 file that was running good. I now have actual and desired iac counts but the truck will not stay running. It fires up and runs for about 10 seconds if you hold the throttle open but then it dies. I made sure that vats is off and all the normal stuff you would think of. If I do a write entire and flash the original 8.1 file back in it fires and runs perfectly. Im lost does anyone have any tips.

What is the PCM part number and hardware number you are using?

[94heritage]

Using a p01 ecm. The 6.0 os is a 12208322
The 8.1 os is a 1272013

[Fast4.7]

Using a p01 ecm. The 6.0 os is a 12208322
The 8.1 os is a 1272013

Good deal, I was concerned you might have a P59 without IAC drivers installed.

Shot in the dark here and you may already know this. Have you switched off the ETC setting in system options matrix? You did not mention what you are using to tune it. If it is HP Tuners, go into the system Tab, General Tab, Systems Option Icon on the upper left under the Platform Type drop down bar. When you open it, will show the whole systems option matrix. If it is a GMT800 file, look on the GMT800 row. The first option is ETC. With DBC it should have 0 there rather than the 1 it was stock.

[94heritage]

I do have the etc shut off in the system tab. Yes I am using hp tuners to tune it.

[5FDP]

Usually helps to post the tune files and logs...

[Fast4.7]

I do have the etc shut off in the system tab. Yes I am using hp tuners to tune it.

Assuming you tried using the basic 8.1L file with the ETB switched off. I have tuned a P59 DBC 8.1L and that was all that had to be done as all the IAC stuff was already there and populated in the code. There is so much not defined by HP Tuners in the calibration I highly caution the copy paste method.

Then again in my G20 van and 99 Tahoe with the 8.1L, I simply used the DBW. 8.1L is one of my favorite swap engines. Where others want a 6.0L, I want an 8.1. Fantastic engines and easier to swap than a LS.