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Thread: EGR Delete OBD1 1994 Corvette

  1. #1
    Carb and Points! lesman's Avatar
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    EGR Delete OBD1 1994 Corvette

    I removed the EGR and AIR Pump when I put headers on the LT1 corvette. I followed a B body EGR Delete that was generated by EEHack online tool. Just compared the bins from a normal LT1 Y body and tried to get everything related to the EGR / AIR pump system. There were too many other related items to check all the differences so I might have missed a couple or so.
    When I ran my logs I noticed I was getting an EGR duty cycle on the graph. After seeing this, I zeroed out the EGR Spark Advance Correction ( I missed that one and added it). The spark advance shouldn't happen any more.
    Is there something to stop the duty cycle of the EGR? It shouldn't be calling it all. I put the maximum RPM to 0 and the minimum RPM to 6500 as in the tool generated bin.

  2. #2
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    Quote Originally Posted by lesman View Post
    Is there something to stop the duty cycle of the EGR? It shouldn't be calling it all.
    I put the maximum RPM to 0 and the minimum RPM to 6500 as in the tool generated bin.
    EGR Min MAP > 103KPa
    EGR Enable Min RpM 6375RpM
    EGR Enable Max RpM 6350RpM
    EGR Enable Coolant Temps (both) > 116C

    No need to zero the EGR table with constants set as above.
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  3. #3
    Carb and Points! lesman's Avatar
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    Quote Originally Posted by LeMarky Dissod View Post
    EGR Min MAP > 103KPa
    EGR Enable Min RpM 6375RpM
    EGR Enable Max RpM 6350RpM
    EGR Enable Coolant Temps (both) > 116C

    No need to zero the EGR table with constants set as above.
    I found the first 3 settings but not the 4th (EGR Enable Coolant Temps). I looked through all the tables and scalars. Using TunerPro with EEX.xdf.
    I found the AIR Enable - Min Coolant Temp and I added 116 for that.
    Last edited by lesman; 03-25-2023 at 05:41 AM.

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    Yes, some of the early stuff was in weird areas, IAT enable egr, watch for that. Either way, it's a one way, both have to pass enable check to qualify. :)
    -Carl

  5. #5
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    Quote Originally Posted by lesman View Post
    I found the first 3 settings but not the 4th (EGR Enable Coolant Temps). I looked through all the tables and scalars. Using TunerPro with EEX.xdf.
    I found the AIR Enable - Min Coolant Temp and I added 116 for that.
    The two EGR Enable Coolant Temp addresses are 2617 and 2618. You can find them using EEXTRA v0[1].001[MOD_V0005_03_02]V6_3.xdf, which can be found here: http://www.gearhead-efi.com/Fuel-Inj...ll=1#post92678
    1990 Corvette (Manual)
    1994 Corvette (Automatic)
    1995 Corvette (Manual)

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    Carb and Points! lesman's Avatar
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    I tried downloading the file but its doesn't load as a valid ZIP file but a RAR file with a ZIP extension add on. When I remove the zip extension and decompress it, it is EEHack executable only. I do not see any XDF file. Where can I find the correct file noted in the forum?
    If it is not available any more, how do I manually add the parameters in Tuner Pro?
    Is there a way I can create a new scalar in the program and add them that way? and if so, what would that process be?

    Edit:
    I found the XDF file that has a lot of the information you referenced. Also some other EGR settings that could be changed. I am still getting a duty cycle graph on the logger but I did not find the XDF till after I made my trip. It was not the one you referenced on page 10 but the XDF on page 6, version 5.
    I will change the settings and give it another shot.
    Last edited by lesman; 03-26-2023 at 01:39 AM. Reason: update

  7. #7
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    The XDF file is attached directly to the post I linked. It's the XDF that you'd want to edit the BIN. There's no reason to grab that modified EEHack executable if you aren't planning on using the custom patches. Just download the attached XDF by itself.
    1990 Corvette (Manual)
    1994 Corvette (Automatic)
    1995 Corvette (Manual)

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    Carb and Points! lesman's Avatar
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    The EGR duty cycle has stopped logging. I changed the settings from the list above and it worked. There are no calls to the EGR cycle or AIR pump anymore.
    I do have other questions on the tune but by me being new to the forum, I do not know if I need to start a new thread or continue on this one here. Its not topic related but a Tuner Pro patch question on the Y body O2 calcs and the Y body MAF calcs. Are these OK to load in my tune? I would also like to load a data run and have some information on what might need to be adjusted or if the systems looks ok.

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  10. #10
    Carb and Points! lesman's Avatar
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    The first values are my default BIN from my Vette. Now these may have been modified by the HyperTech programmer that I have when I adjusted the fuel for higher octane. The tool they sold for the C4 94-95 LT1 was very limited but I guess for back then it was great. Default octane rating from factory was 89 but this tool moved it up to 91 - 93. It also firmed up shift point and various curves but as I said very limited. Mainly yes or no questions but there was some data entry areas that I did not fool with. Power Programmer Plus. They are right around the corner from my house.
    This is a comparision of the bin file taken as backup and the patched file from Tuner Pro. the right hand side is the Tuner Pro patch.
    Which ones would be more effective?
    patched O2-MAF.jpg

  11. #11
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    I've seen the Hypertech """"tune"""" from the device for the 94-95 Corvette, as my '94 Corvette's previous owner had used it. It's garbage, like most of Hypertech's stuff is. You'll be glad you're just doing the tuning yourself.

    I did save a copy of the changed BIN just for reference, but then promptly undid Hypertech's changes and just implemented my own instead.
    1990 Corvette (Manual)
    1994 Corvette (Automatic)
    1995 Corvette (Manual)

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  13. #13
    Carb and Points! lesman's Avatar
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    I have the factory bin stored in the old programmer so I can push it back into the unit and start from there. I found the 16181333 BKFS bin the file area. My 16181333 has a BKFS suffix also. In case the storage is scrambled, would be this be the upload to start with?
    Also, some have said the 16188051 LT1 ecm is a replacement (to a degree) for the 1994 Corvette LT1. I know there was added components in the 16181333 for the future ODBII addtion that didnt come until 1996. It may be a dumb question (and over the years I have asked a many of them), would there be any harm in using this as a tester since I would hate to accidently tank my factory ECM? I have one of them.
    Last edited by lesman; 04-02-2023 at 07:07 AM. Reason: update

  14. #14
    LT1 specialist steveo's Avatar
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    you can totally program a y-body bin to the f-body/b-body 8051 ECM and use it in your 'vette. they are interchangeable-ish, the extra code for the diagnostic crap doesn't do anything worthwhile, in fact i have a patch that replaces it with something more useful (a shortened datastream message to get a higher sample rate when logging with eehack)

    if you are flashing the 8051 ecm with a y-body bin for the first time in-car you might have to pull the fuse for the CCM for that initial flash, since they will fight over who runs the ALDL bus, in a y-body the CCM runs the aldl bus and in the other cars the ECM does....but my hunch says flashhack will probably figure it out and work anyway after a few attempts.

    here's every bin we've found so far, including factory code patches, just pick the one that matches your car and go for it. you could even look at the 1995 bin and get some ideas, i know they revised a few things but the engine itself did not change, but i think you will want to run the 1994 bin they are by calibration ID number not broadcast code though. there are only three choices for a 1994 'vette, and two of them are just different final gear ratios (so speedo calibration and shift points are different)

    http://ecmhack.com/tutorials/bin-files/

  15. #15
    Carb and Points! lesman's Avatar
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    Yes,
    I found the LT1 8051 ecm on a Buick Roadmaster a while back. When I first tested the replacement theory I though the ecm was junk, couldn't talk to it very well in the vette. Searched every where for a solution on why it wasn't talking and in a far away forum, deep into an old thread, was a suggestion that the 8051 gets confused from LT1 to other LT1 models. They said to pull the CCM fuses till it talks. I pulled CCM2 and it came to life. Programmed right up.

    I appreciate all the help. Even though the opti has bit me many a time, I still love my vette LT1.

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