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Thread: 24* Knock retard, no knock counts

  1. #1
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    24* Knock retard, no knock counts

    I'm trying to tune a '93 K2500 with a 350 TBI, 82,000 miles, only modification is a K&N air intake. ECM# 16168625, using a $E6 mask. I'm getting 24 degrees of knock retard with no knock counts. I used to have thousands of knock counts per second, but I plugged the stock backup resistor network pack on to my memory adapter, which made the knock counts go away. I read about doing this in a post and tried it. I have no idea why this works, and would love an explanation, but it solves the problem of having 20,000 knock counts a second. Back to the real problem; the knock retard has not gone away. I have unplugged the knock sensor and changed every table that I think could possibly influence the knock sensor. I still have 24 degrees of knock retard. Does anyone know why this is? It seems to me that the issue has to be somewhere in the code, but I have no idea where it is. I started tuning with the BDJZ bin off of this website and the .ADX and .XDF files from Tunerpro. I have attached my bin, .ADX and .XDF files. My bin is far from perfect, but I have only started to tune it. I have many, many things that I still have to learn. Distributor timing is at 0* per the factory settings. I advanced the timing 10* across the board in the main spark table for both open and closed throttle, so that it will drive somewhat decently down the road.
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    did you mod the bin to change from battery volts being sent out in the datastream to knock retard like it says in the notes at the top of the xdf if not your logging batt volts i presume
    Last edited by delcowizzid; 05-22-2014 at 07:40 PM.

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    24 / (45/255) = ~141

    if it is battery volts, then ~14.1 volts, which is certainly believable.
    1995 Chevrolet Monte Carlo LS 3100 + 4T60E


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    Post the TP data log .xdl file so we can see what's going on.

    Do you hear any knock,ping etc...? How's the motor run? Any other truck noise?

    One thing to look at is does the knock sensor match the knock module in the Memcal? There are a couple differant ones, manual and auto. I'd go back to all stock knock settings or even a fresh bin to start. Loose the 10* across the board timing for now so we have a benchmark, then a data log would be even better. But any data would be good for now.

    Some systems just keep retarding when something is wrong, either in degress or knock counts. Like a short or broken wire, check contiuity from knock sensor to pin at PCM.

    Also if you have over tightened the knock sensor at some point in time? It's shot! They squeze shut and always think theres knock. Do you have any other noise? Yes exhaust rattle, motor mount vibrating, etc... I understand no knock counts, but for some reason can still have retard... seen it but don't know why?

    1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
    1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
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    i just edited my post so it looks like i know engrish better cant beleive what i just read must of been tired LOL.i dont think he has any wiring or sensor issues now hes fixed the constantly revolving knock counts he had with no memcal fitted.i just looked in the bin its set to output batt volts thats why its at 24 the whole time LOL

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    I started with a new bin today and changed the bin to output knock retard instead of battery voltage. The XDF says to change the value at L51FE. I changed it through the scalar, which then causes the change at L51FE. I think that L51FE is a reference in hex. Is this correct? How do I view L51FE?

    I have not had a chance to run the truck yet(not my daily driver). I will run it tomorrow. If the 24* that I was getting in the knock retard box was really battery voltage(after going through an equation), does the computer read the 24* and then think that it needs to retard timing by that much? Something is causing this truck to have absolutely no power at all. Advancing the timing is the only way that I could get it to run halfway decent. That is why I advanced the timing 10* everywhere. Thank you all for the help with this.

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    no that change is so the ecu outputs spark retard instead of battery volts via aldl.it should have no effect on spark advance .

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    Quote Originally Posted by delcowizzid View Post
    no that change is so the ecu outputs spark retard instead of battery volts via aldl.it should have no effect on spark advance .
    ^^ X2 ^^

    Post a data log so we can see what's going on!

    1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
    1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
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  9. #9
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    Even though I would have waited until the problem was resolved, my brother decided that now was the time to install a set of long tube headers and full exhaust. He couldn't wait any longer to get the computer fixed before he put the new parts on. (In his defense, the truck now sounds great) My apologies to you for having to now deal with this change to the truck.

    I drove it around with the stock BDJZ bin(after making the modifications recommended). It still doesn't have a whole lot of power. It takes a lot of pedal effort to get it to move any faster. I think the only reason it drives a little better now is because it is breathing easier, due to the headers/exhaust. BLM's show that it is running way rich when cruising. I will put the wideband in it tomorrow and do another data log.
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    Forgot to add that I plugged the knock sensor back in.

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    To clarify a previous statement, the truck that I am tuning is my brothers.

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    I must have been on something when I drove the truck last night. It drives perfectly fine today. Thanks to everyone for their help with this.

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    Quote Originally Posted by hellomynameis View Post
    I must have been on something when I drove the truck last night. It drives perfectly fine today. Thanks to everyone for their help with this.
    Were and how in bin did you change this exactly I have same ecm and my knock is constant 25 degrees idle up and never goes up or down I believe it's set to battery voltage too . But I can't find it

  14. #14
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    basic question - I have 93 C1500 using 16168625 with standard code BDJZ. I haven't modified anything. I am using TunerPro RT and same .adx & .xdf as above in thread.
    A201_E6_v250.adx & E6_TPV5_v250.xdf

    I read constant 24* knock retard with only low level of knock counts.
    I see in .adx file this comment for knock retard - For data logging "Knock Retard" instead of "Battery Voltage". The bin must be change at L51FE to support this.

    Since I have not modified bin running - I assume this means that standard code outputs battery voltage in datastream, not knock retard.
    Is this correct?

  15. #15
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    Yes outputs batt volts stock

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