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Thread: 95 LT-1 Idle Cell Comparison - Humidity?

  1. #106
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    Quote Originally Posted by spfautsch View Post
    , but I was seeing airflow from the MAF and the green indicator was lit the entire time.
    You have just found another bug in the patch related to manual transmission. It turns out that the routine that makes the switch between maf and speed density modes doesn`t run with manual bin. An easy fix for the next release.
    So for now the sd/maf switch will be unoperational on manual bins till the next version is out.

    If you are eager to test sooner there is only one byte that needs to be fixed for the button to start working.
    AT $A0C9 change the stock value of $F8 to $54 in hex editor and save. Than save the bin with tunerpro to update the checksums and flash with eehack.

  2. #107
    Fuel Injected! spfautsch's Avatar
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    I'll press on tuning SD with the MAF disable flashed. Hoping to have VE "close enough" by tomorrow. After that I may need some advice on the MAF pumpshot tuning.

    Once you have the patches finished I'd be happy to test.

  3. #108
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    Here is the first beta source.

    If you have a socketed pcm and wants to be a guinea pig go ahead.
    My only concerns are for some typo errors in the patch section. Otherwise I am sure you will like the new controller interface. It is also resizable and can hide the less used stuff.

    With delta ve control you can nail the overall off condition really fast.
    Attached Files Attached Files

  4. #109
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    I justflash a stock bin with the beta and evrything looks fine. There is no brick situation and the engine starts. I didn`t have the time to test functionality.
    So you can safely flash with the beta. There will be no suprises.

    I also noticed how to add info buttons to explain how to use the extra controls. Next on the list.

    Now with stock bin I found that the engine starts harder, at the 3rd 4th attempt, but the cold idle was incredibly smooth and tamed. I haven`t heard the engine running that healthy from a long time.
    So what was the difference. 4 less degrees advance, stock underspeed and maf tables and much more fuel being dumped. I guess I need to be back on the tunnig board.

    Some log for comparison.
    Attached Files Attached Files

  5. #110
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    I'll probably pass on testing until I'm done getting my tune at a respectable baseline - it's coming along really well so I'd rather not get distracted with other stuff right at the moment. I've been switching between your fork and an old version of the original that I've customized.

    Quote Originally Posted by kur4o View Post
    Now with stock bin I found that the engine starts harder, at the 3rd 4th attempt,
    Are you stock cubes but bigger injectors?

    I've been messing with that 12680 multiplier with the stock base pulsewidth table. For the sake of discussion let's call it a two byte table where both bytes must match (similiar to the target AFR tables). I followed your advice at first and used 0x44 (in both bytes). It seemed to be a little lean - hot restarts popped right off if I bumped the key and then hit it again after 5 seconds. So I went to 0x55. It hits every time but seems to be pretty rich there. I tried 0x4F and it still seems a bit rich so I'm working my way down from there. Whatever the case it's hitting on the third or fourth low res pulse every time now regardless of ECT.

  6. #111
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    an old version of the original that I've customized
    You can share the new goodies and I can try to include them in the new release. The key shortcuts are very usefull, I still haven`t had the chance to expand them to more controls.


    The 2bytes table whenever is changed, the prime pulse tables must be adjusted to compensate for the new offset factor.

    With stock settings at $6666 the stock table will look like this
    215.63 215.63
    209.38 209.38
    120.31 120.31
    59.38 59.38
    39.06 39.06
    17.19 7.81
    12.50 6.25
    7.81 4.69
    7.81 4.69
    7.81 3.13
    6.25 3.13
    6.25 4.69
    6.25 4.69
    6.25 6.25
    6.25 6.25
    When the 2 byte table is changed to $4444
    The table will look like this with new conversion factor (1.007028* X) + 0.000000
    138.97 138.97
    134.94 134.94
    77.54 77.54
    38.27 38.27
    25.18 25.18
    11.08 5.04
    8.06 4.03
    5.04 3.02
    5.04 3.02
    5.04 2.01
    4.03 2.01
    4.03 3.02
    4.03 3.02
    4.03 4.03
    4.03 4.03
    So whenever the 2 byte table is changed you need to readjust the prime pulse tables.
    With $4444 scalar the resolution goes to 1ms intervals vs 1.5 ms at stock $6666 settings.

    hot restarts popped right off if I bumped the key and then hit it again after 5 seconds
    I have done this on a cold start with the same result. Adding fuel didn`t help at all, so my assumptions it is actually rich.
    Hot restarts are tricky to tune and test due to some variables that can change on the fly. The main issue will be how much fuel left on the walls unburned with the engine switching off.

    The prefect start will be at sub 0.3seconds only on the prime pulse fueling. Than the crank ve tables hit with 2 different afr tables based on low res pulses.

    I found some 96 lt4 bin and explore the differences. The idle advance is set at 19* at cold coolant and gradually decrease to 14* while warming. On the lt1 f-body is reversed. Really interesting.



    I have changed the injectors onlyThe ls` ones flows 24lb at 3bar, so no change with fuel flow. With the old some crap accell 24lb/hr I didn`t have any hard start issues even with completely stock bins.
    So it could be the injectors needs some tweeking or the ls1 injectors patch I run needs some attention at starting routine.



    I also tried the vette CL settings and the logs I made are on par with yours. Slight blm split and less crosscounts. The idle runs perfect in closed loop.
    I have some theory how to tune the CL settings for more crosscounts, but need to test some of them to confirm how they work.

    The off idle trims made huge difference at cruising around 1500rpm. I wonder how far we can go using them safely before the air stream equalize in the cylinders.

    Stock settings are at 0-14% tps, <3000 rpm and no catprotect and PE.

    On the lt4 bin the tps is at 24%.

    I want to increase the tps as much as possible and add new conditions such as airflow or map thresholds.

  7. #112
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    Quote Originally Posted by kur4o View Post
    You can share the new goodies and I can try to include them in the new release. The key shortcuts are very usefull, I still haven`t had the chance to expand them to more controls.
    There really isn't anything new or terribly worthy of sharing. I did recently fix a problem where the IAC override would set it to 4 (steps) and not change if switched to step mode. But that might have been a bug I created. Aside from the key accelerator stuff it was mainly making fields like knock count and stuff big enough this old blind guy could see them on the 11" screen.

    Quote Originally Posted by kur4o View Post
    With stock settings at $6666 the stock table will look like this

    ...

    When the 2 byte table is changed to $4444
    The table will look like this with new conversion factor (1.007028* X) + 0.000000
    I think I'm pretty clear on that. I suppose what I'm confused on is if I were to set 12680 to 0x4c4c why wouldn't the prime pulse table look like this with 1.16ms intervals:

    Code:
    160.034    160.034
    155.396    155.396
    89.294    89.294
    44.067    44.067
    35.950    35.950
    17.395    17.395
    12.756    12.756
    5.798    5.798
    5.798    3.479
    5.798    2.319
    4.639    2.319
    4.639    3.479
    4.639    3.479
    4.639    4.639
    4.639    4.639
    ???

    You won't hurt my feelings to tell me why I'm being a bonehead as long as I can learn something from it.

    Quote Originally Posted by kur4o View Post
    Hot restarts are tricky to tune and test due to some variables that can change on the fly. The main issue will be how much fuel left on the walls unburned with the engine switching off.

    The prefect start will be at sub 0.3seconds only on the prime pulse fueling. Than the crank ve tables hit with 2 different afr tables based on low res pulses.
    You'll get no argument from me that restarts in general are tricky with different injectors, displacement, etc. I tested the above multiplier tonight (0x4c4c) and had a very obvious flood at 73c restart (fired then died, required pedal to clear on 2nd attempt). This is why I was curious if we have any idea if injector offsets are added to the prime pulses. Then we get to the subject of having good injector data. My ecm is seeing 10v average during cranking. that's about 1ms of offset for the stock injectors. If my offsets are wrong, how far off are they?

    Quote Originally Posted by kur4o View Post
    So it could be the injectors needs some tweeking or the ls1 injectors patch I run needs some attention at starting routine.
    You should put my experimental ignition system on it so you have another unknown! (joking)

    Quote Originally Posted by kur4o View Post
    I also tried the vette CL settings and the logs I made are on par with yours. Slight blm split and less crosscounts. The idle runs perfect in closed loop.
    Mind sharing a screenshot of the BLM analysis?

    I'm pretty happy with my VE table after tonight's log so I think I'm going to turn the MAF back on and fine tune a bit. Probably mostly on the damned prime pulse / restart issue. Beyond that I'd be happy to test any closed loop tweaks you would care to share.

    Quote Originally Posted by kur4o View Post
    I want to ... and add new conditions such as airflow or map thresholds.
    If you can do that I can surely conquer startup fueling.

  8. #113
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    why wouldn't the prime pulse table look like this with 1.16ms intervals:
    It is exctly like that. I have nothing to add. What I mean is that you can fine tune the tables from there.

    So for now I want to end the disscusion on the pw scalar since it is all clear.

    The 2 bytes table should be called. Multiplier to startup prime PW table.

    The formula for the multiplier will be d={x*0.0152587891}/256

    The multiplier decimal result must be entered in the crank prime tables conversion field with the following formula {x*d}.

    Now you can start fine tunning with the new multiplier.


    The InJ vol offset are for sure used during cranking. I improved that part of my patch with major improvement on the first start attempt.

    I am starting to suspect that my ls1 inj flows more than specified at 100kp range. That explains the hard startup[rich condition] with stock settings.

    I am getting rich right side at cell 6 only, 3-4 points split. I check logs with older settings and the split is also there at #6 cell. At other cells the split is negligible.
    I also changed the off idle trims but it seems they don`t affect the split.

    I experience zero split at idle so far. I tested it for a short period so it could be not very reliable.

    I thought for a way how to find the break point for off idle trims condition.

    Setting the trims on one of the side richer and look for the conditions where the blm splits equalize.
    Than set the tps map thresholds.

    I already made the map threshold patch but it interferes and interacts with the v5 patch so it is a little tricky to install. If you want to give it a try I will set you a bin. If it turns out bad I can change it to an air flow condition.


    I suspect the $26fb table to be responsible for the crosscounts. It is also the cure for idle CL along with the swing voltage.
    AT $26fb slightly increasing the values at cells 2-5[don`t touch the first cell- it is for idle]

    y-stock ;f-stock ; my old settings
    0.40 0.80 1.20
    0.18 0.18 0.35
    0.13 0.13 0.25
    0.11 0.11 0.23
    0.10 0.10 0.20
    As you can see I thought more is better but not for the first cell. For the first cell less is better, almost twice less at stock y-body vs f-body.
    At cell 2-5 increasing the value can lead to higher crosscounts. Field discovered by mistake. Not sure how good is this for engine running healthy but you can give it a try.

    $270c is also different but not in the idle region. It also can attribute to the crosscounts but needs testing.
    The main difference is at cells 2-5
    vette; f-body
    0.3 0.5

    and the swing voltage
    380 for vette
    vs
    460 for f-body

  9. #114
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    Your problems with hot restart might be due to crank spark advance. I ripped the settings from different calibrations.

    Interesting I am running 2 degrees at 80*C and 7* at 20*C stock. The closest to cammed car is lt4 setting at 5* and 11*, all other calibrations have 8-10 * and 13*.

    I suspect this might be culprit with my issues of first cold start.

    So it could be hot restarts needs less advance and first cold start needs more advance.
    Attached Files Attached Files

  10. #115
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    Interesting there's that many differences between the stock bins. On a whim I just tried the lt4 cranking spark table. Before this change pretty much all starts with anything under 0x50 in 2680 was somewhat slow and slobbery. With the lt4 startup spark it start and ran cleanly. Still hit on the 3rd or 4th low res pulse.

    Unfortunately the weather has changed dramatically here so I almost need to wrap my engine and radiator in a blanket to get a hot restart at 80 ECT. Ambient is > 10c cooler than last weekend so air density way different also.

  11. #116
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    The lt4 bin also have a lot more fuel at startup. No idea why.

    Here is printout for most of the popular combos.
    Attached Files Attached Files

  12. #117
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    Curious what the 12680 multiplier is - the injector constant shows 27 lb/hr. I didn't know the LT4s got bigger injectors.

    They did get completely different heads and redesigned intake with taller ports so that would explain the different individual trims.

  13. #118
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    Code:
    RESERVED:2B41                 fdb $34BC               ; prime pulse table multiplier
    RESERVED:2B43                 fcb $C3 ; +             ; initial prime pulse set
    RESERVED:2B44                 fcb $AE ; î
    RESERVED:2B45                 fcb $63 ; c
    RESERVED:2B46                 fcb $3A ; :
    RESERVED:2B47                 fcb $2C ; ,
    RESERVED:2B48                 fcb $1B
    RESERVED:2B49                 fcb $14
    RESERVED:2B4A                 fcb   9
    RESERVED:2B4B                 fcb   9
    RESERVED:2B4C                 fcb   9
    RESERVED:2B4D                 fcb   7
    RESERVED:2B4E                 fcb   7
    RESERVED:2B4F                 fcb   7
    RESERVED:2B50                 fcb   7
    RESERVED:2B51                 fcb   7
    RESERVED:2B52                 fcb $F4 ; ¯             ; first prime pulse adder
    RESERVED:2B53                 fcb $ED ; ý
    RESERVED:2B54                 fcb $88 ; È
    RESERVED:2B55                 fcb $43 ; C
    RESERVED:2B56                 fcb $37 ; 7
    RESERVED:2B57                 fcb $1B
    RESERVED:2B58                 fcb $14
    RESERVED:2B59                 fcb   9
    RESERVED:2B5A                 fcb   9
    RESERVED:2B5B                 fcb   9
    RESERVED:2B5C                 fcb   7
    RESERVED:2B5D                 fcb   7
    RESERVED:2B5E                 fcb   7
    RESERVED:2B5F                 fcb   7
    RESERVED:2B60                 fcb   7
    RESERVED:2B61                 fcb $F4 ; ¯             ; 2n prime pulse adder
    RESERVED:2B62                 fcb $ED ; ý
    RESERVED:2B63                 fcb $88 ; È
    RESERVED:2B64                 fcb $43 ; C
    RESERVED:2B65                 fcb $37 ; 7
    RESERVED:2B66                 fcb $1B
    RESERVED:2B67                 fcb $14
    RESERVED:2B68                 fcb   9
    RESERVED:2B69                 fcb   9
    RESERVED:2B6A                 fcb   9
    RESERVED:2B6B                 fcb   7
    RESERVED:2B6C                 fcb   7
    RESERVED:2B6D                 fcb   7
    RESERVED:2B6E                 fcb   7
    RESERVED:2B6F                 fcb   7
    The multiplier is $34BC, I suspect the conversion is set wrong on the data I have. You can recalculate the tables with that scalar.


    There are some extra tables added on the lt4 bin.

    Mat adder to MAF, useful at cold start lean
    and MAT spark correction. can save engine at high load and high mat.

    It will be relatively easy to add them to 94-95 code. Will be there any benefit of them.

  14. #119
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    While investigating my hard start issue I measured my fuel pressure and what a surprise. The crap adjustable aeromotive unit holds different pressure during pump priming. On a random basis it opens at either 2.8, 3.0 or 3.2 bar. Interesting when the engine starts it frozes at 3 bar. There is also high frequence oscilation in the gauge pointer when the engine runs. It doesn`t move but it is kind of vibrating. Could this be the reason for lack of fuel rail damper.

    The flow rate range from 24lb/hr at 2.8bar to 25.6lb/hr at 3.2 bar. A huge difference for proper fuel at starting.

  15. #120
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    Just wanted to report back that I've think I've made some progress on the startup tables.

    The LT4 cranking spark table didn't seem to solve any problems by itself. I'm currently still running it, but ended up scaling the BPW multiplier to the point the resultant prime table was about 12% rich of original when corrected for injector slope (a total of 22% with the adder for displacement). This got things to a point where it fires nearly immediately in most conditions. In warmer cells I continued to notice a start then die condition that I suspected was flooding. Reducing the initial AFR enrichment in the effected cells (table 0x12b10) seems to have helped. The only obvious remaining warm restart issue I've experienced is a point when it's been sitting for 2-1/2 to 3 hours and it will fire immediately and stay running but seems like it's struggling to do so for the first several seconds. As much as I'd like to develop a scientific method for tuning this, it seems like the cam overlap complicates things.

    Anyone have any wisdom on how the IAC adders related to a/c work? I'm feeling surge at low throttle cruise when the compressor clutch engages. There's a scalar / multiplier at 0x2691, a pressure vs steps(?) 2d table at 0x2692 and another 2d table at 0x26a3 with unknown row labels. I'm seeing IAC jump about 20 counts when the compressor output is enabled at cruise speeds, but I'm not seeing anything close to 20 in any of the tables so wondering if 0x2691 is a multiplier.

    Also wanted to mention I was shocked how much more fuel it consumed the two days running in SD mode. 18.5mpg makes me wonder if I wasn't tripping on something when I read the pump after the previous fill-up (29.4mpg).

    Edit: Sorry didn't see your post about fuel pressure before submitting this, but that's another item I changed that I can't help but think has thrown my startup fueling off. I'm hoping to check mine against another shop's gauge this week to see if theirs is any more accurate. Mine reads 40 psi with the pump running.

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