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Thread: 1992 P30 7.4 / 4L80E M.H. Chassis

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    Fuel Injected! dktool's Avatar
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    1992 P30 7.4 / 4L80E M.H. Chassis

    This vehicle is bone stock original, it has a dead band around 60 - 70% throttle that I have been chasing. The following statement is what I have found as the cause, any input on obtaining a chip or complete ecm that does not have this trait would be appreciated; "After a long delay, I finally took a 2 hour trip with my laptop on the dash in gauge mode running TunerPro V5, what I observed confirmed that the dead band is indeed a result of spark advance being pulled, BUT....... It is not a result of knock count, which over the course of a 2 hour drive at freeway speed including a few pulls up grades, the total knock count only increased by single digits. Here is where the problem lies; Contrary to common knowledge on how an egr system would work to cool combustion chamber temps under hard load, what this ecm does is that past a certain percent of throttle opening,(55-65) modulation of the egr goes to zero (no egr) and at that exact time the timing advance drops from, depending on load, from 25 to 30 to as low as 12 degrees. Now, how can an engine spinning at 3200 rpm at 80 to 90 percent throttle opening make any horse power and torque with 12 degrees of total btdc advance, answer it can't ! I could pedal the throttle and watch the egr and advance toggle on / off, up / down and feel the power follow suite. So, with the new insight, it would appear the only cure would be to have an ecm the didn't have this way over the top engine protection function.

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    Super Moderator dave w's Avatar
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    One experiment would be to disable the EGR in the chip programming and try to replicate the dead band. If deleting the EGR solves the dead band, then re-enabling the EGR and experimenting with the EGR tables might be the long term solution. dave w

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    Fuel Injected! dktool's Avatar
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    Quote Originally Posted by dave w View Post
    One experiment would be to disable the EGR in the chip programming and try to replicate the dead band. If deleting the EGR solves the dead band, then re-enabling the EGR and experimenting with the EGR tables might be the long term solution. dave w
    I assumed that a re-program of the EGR function would be needed. Can the chip be sent to someone to burn a copy of it and modify the ERG table ?

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    Super Moderator dave w's Avatar
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    In the long run, burning your own chips offers the best solution..........A Burn 2 chip programmer from Moates.net http://www.moates.net/burn2-chip-pro....html?cPath=64 A G1 Adapter Board http://www.moates.net/g1-memory-adap....html?cPath=64 a chip http://www.moates.net/c2-sst-27sf512....html?cPath=26 will be the nuts and bolts needed for burning you own chips........An optional quick release chip socket (ZIF - Zero Insertion Force) http://www.moates.net/s4-aries-28pin....html?cPath=26 is nice but not necessary......The learning curve is steep to burn your own chips? dave w
    Attached Images Attached Images
    Last edited by dave w; 12-22-2016 at 09:51 AM.

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    Fuel Injected! dktool's Avatar
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    Quote Originally Posted by dave w View Post
    The learning curve is steep to burn your own chips?
    This is what I was afraid of.

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    Quote Originally Posted by dktool View Post
    This is what I was afraid of.
    Don't let Yoda (Dave) scare you. I think he asked a question. You are already way up the learning curve. I was able to burn chips within a couple of days after getting an Autoprom from Moates. The real trick is knowing what, why, and how to change the data. Stick your toe in, the water isn't as cold as it looks. Bob
    Last edited by uncabob; 12-22-2016 at 05:46 PM.
    Don't force it, get a bigger hammer!

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    Fuel Injected! dktool's Avatar
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    Quote Originally Posted by uncabob View Post
    Don't let Yoda (Dave) scare you. I think he asked a question. You are already way up the learning curve. I was able to burn chips within a couple of days after getting an Autoprom from Moates. The real trick is knowing what, why, and how to change the data. Stick your toe in, the water isn't as cold as it looks. Bob
    I do feel capable enough from the PC, mechanical and the logic side of it, I have written and done PLC programming for machine tools so in a lot of ways as you say, I am already way up the learning curve, but my main area of concern is exactly as you stated, "The real trick is knowing what, why, and how to change the data." Just finding a ADX file that would communicate with the TP software was a challenge as my ecm number was not shown on Moates support page and another source did not show it either. I first tried one that Moates suggested via email and it did not work so after reading a lot on this board and find some of Eagle Mark's ( R.I.P.) posts I tried the $85 file and it worked, it even had his name referenced in some of the sub tabs / edit windows. It was suggested that my ecm was a replacement unit, I know the history of this vehicle and am confident it has never been touched, it is: 16175071 I have not removed it to see what the prom or calpak(?) numbers are. Can the Burn 2 unit simply make an exact copy of my current chip then I can cut my teeth on that one trying to change the data ?

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    Super Moderator dave w's Avatar
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    Quote Originally Posted by dktool View Post
    Can the Burn 2 unit simply make an exact copy of my current chip then I can cut my teeth on that one trying to change the data ?
    Yes... http://support.moates.net/beginners-programming-chips/ ....The 27SF512 chip that Moates.net sells is 64K in size. $85 is 32K in size. You will need to use an "Offset" for the Burn 2 http://support.moates.net/programmin...using-offsets/ It's hexadecimal 32K = 7FFF and 64K = FFFF. dave w
    Last edited by dave w; 12-23-2016 at 12:16 AM.

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    Quote Originally Posted by dave w View Post
    Yes... http://support.moates.net/beginners-programming-chips/ ....The 27SF512 chip that Moates.net sells is 64K in size. $85 is 32K in size. You will need to use an "Offset" for the Burn 2 http://support.moates.net/programmin...using-offsets/ It's hexadecimal 32K = 7FFF and 64K = FFFF. dave w
    I read those links, so far so simple. (haha) So the $85 file I have on my laptop contains all the operating perimeters for the ecm and I don't need to burn an image of my current prom ? Will I also need the bin or any other file or only the adx ? Then there is the question of instruction for finding the egr table and disabling it to prove the problem. Then, how to modify the trip point to something like cutting the modulation to a near zero percentage at the dead band trip point in hopes it won't pull the advance back with it. Also, I have no experience with the hexadecimal language so that also needs to be learned ! I have made my career by being self taught so if it's doable with only "virtual" teachers then, I'm in.

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    If it were me I would copy the chip you have in it now and use that as your starting point as that bin might have MH transmission settings that are different than bins you might gather from pickups or suburbans.
    6395, BHDF, 7.4 BBC lightly modded now 6395 BMHM back to BHDF

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    Quote Originally Posted by myburb View Post
    If it were me I would copy the chip you have in it now and use that as your starting point as that bin might have MH transmission settings that are different than bins you might gather from pickups or suburbans.
    That was my thought too, I'm sure it has other functions that are not present in the smaller truck models such as gear ratio, decel speed fuel cut etc. This thing starts, runs and shifts like a swiss watch, it's just this one thing that make an already de-tuned Mark 5 emissions engine feel like dog, but only at that one point, through out the power band up to that, it pulls good. The fact that it is a P30 (P37) M.H. chassis is more than likely why it has this funky program. In all the searches I have done, the only ones that came up with this dead band comment were in RVs.

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    Super Moderator dave w's Avatar
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    Quote Originally Posted by dktool View Post
    Then, how to modify the trip point to something like cutting the modulation to a near zero percentage at the dead band trip point in hopes it won't pull the advance back with it. Also, I have no experience with the hexadecimal language so that also needs to be learned ! I have made my career by being self taught so if it's doable with only "virtual" teachers then, I'm in.
    The Hexadecimal information is for using Offset and for actual binary coding of the .bin file location / address (advanced class student stuff) The beginner can do very well without ever having to use Hexadecimal coding in the .bin file! Understanding Hexadecimal file size is needed for burning a chip with "offsets"..... Attached are some screen shots of the $85 transmission parameters and tables. I also included a screen shot of the Hexadecimal location in the .bin for $85, which is not necessary to know as a beginner! dave w

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    So, to be clear...... with the Burn 2, I would remove my prom, put it in the Burn 2, copy the image to my pc, remove the prom, put a new blank one in and upload / burn the saved image from my pc to the new chip. Is this correct ? Also, what is the function of the "calpack" module ? I see that the Moates chip adapter consumes the space where the calpack is.
    Last edited by dktool; 12-23-2016 at 05:54 AM.

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    Super Moderator dave w's Avatar
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    Your $85 computer uses a Memcal, see my previous pics. Attached is a Memcal pic without the blue cover, showing the soldered in chip and knock filter board. To read the PROM chip from a Memcal I use the Moates.net HDR1 header http://www.moates.net/hdr1-memcal-he....html?cPath=64 which plugs into the Memcal so the Burn 2 can read the PROM chip.... Just a note, learn where the #1 pin is on a chip!!! http://www.evilmadscientist.com/2010...finding-pin-1/ dave w

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    Quote Originally Posted by dave w View Post
    Your $85 computer uses a Memcal, see my previous pics. Attached is a Memcal pic without the blue cover, showing the soldered in chip and knock filter board. To read the PROM chip from a Memcal I use the Moates.net HDR1 header http://www.moates.net/hdr1-memcal-he....html?cPath=64 which plugs into the Memcal so the Burn 2 can read the PROM chip.... Just a note, learn where the #1 pin is on a chip!!! http://www.evilmadscientist.com/2010...finding-pin-1/ dave w
    Just as I was starting to see some clarity it looks like the fog is rolling in ! So now I am reading the prom via the Memcal ? How can the Burn 2 unit connect to the Memcal via the memcal header if it is still in the ecm and the Burn 2 is configured to except a prom chip ? So confused......... :) Edit: After some searching, some clarity is coming back, I think ! Here's my take; The Mencal board containing the prom is removed from the ecm, the board plugs into the Mencal Header which in turn plugs into the Burn 2, is this correct ? Why not just remove the prom chip and copy it ?
    Last edited by dktool; 12-23-2016 at 08:05 AM.

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