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Thread: E67 LSX stalling/idle/fuel smell tuning 7.0L CTSV light clucth medium cam

  1. #21
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    The follower torque tables are weird on this ECM, E67 is like somewhere in between gen4/5 I guess, seems to be missing things that it should have. There isn't engine torque values , it's all coefficients except the follower values. This thing is a huge PITA compared to a haltech or holley. I think it's missing some tables. Can't even log certain PIDs as they seem to be straight up missing from either hptuners or the ECM itself. I got it pretty close though by adjusting the follower values and cranking up the min air.
    For example, the thing will idle fine at 9g/s min air, but if i blip the throttle it dies on the way down (bypasses the idle point and goes to 0 like it's not even trying).
    So I set the min air to 10.8g/s and it is catching it on the way down but still goes past idle, however setting the min air up that high caused a lot of idle hangs and cruise control type effects so I adjusted the throttle follower tables (added a lot more over stock for the higher rpms and less around 1k rpm) which then got rid of the cruise control like effect or high idle hanging for a while.
    So what I'm thinking is I need more min-air, even though technically it doesn't need it to idle, but it needs it to keep the rpms from dropping too fast near idle so it has time to react.
    This seems to be a combination of min air and follower values. I also tried adjusting the proportional table around idle and see if that makes any difference, it's coefficient based and so far i haven't noticed any change when modifying it even 50%.
    The lack of documentation on what table it is using and when is really frustrating. I'm pretty sure this issue is due to my super light carbon fiber/aluminum clutch setup the rpms drop like a rock at lower RPM values like 1500 and below due to really low rotating mass, even my crankshaft is lightweight.
    Engine is basically similar to LS7 with heads,cam,intake,headers,lightweight clutch

  2. #22
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    You've actually made all of your adjustments to the tables that manage the follower airflow when it's already in a transition towards or away from idle airflow. These are only filters on the airflow change, not the initial airflow itself or its ramp rate. Unfortunately it looks like you don't have the primary table available - the feed-forward throttle follower torque table where all of this calculation starts from. I'd definitely email HP Tuners support on that one.

    You do still have the throttle follower step tables, and those definitely need to be reduced. That should help some of your problem at least. Can't be done totally right without that main throttle follower table though.

    I know the file you posted was months ago and you probably have changes since then, but couple things...set min RPM reference back down to the stock value for now. Setting it at 800rpm disables all closed loop idle control if RPM ever falls below it. That close to your idle speed with an already unstable idle will actually cause oscillation...you'll notice your alternator dropping out there because it thinks it is already close to stalling and is shedding load to keep the engine alive. And set proportional RPM error back down to 50 or so. 150 can also cause oscillation lol. I didn't look at anything else, but try that stuff first.
    Last edited by smokeshow; 03-31-2021 at 08:24 PM.

  3. #23
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    Thanks. I made a bunch of changes and it's way better. Fuel smell is better with these changes (eoit and proportional fueling).
    The car idles great, i mean, it has idled great for a while, the main problem isn't stationary idle , it's when adaptive idle is off.
    What I did was set the VSS for adaptive idle to 15 mph and now it's perfect in parking lots etc. I was just going to set it to 999 mph so it's on all the time but I'm not sure that is a good idea or it would be that way from the factory.
    So what happens is, now, when I'm over 15mph I can get it to stall by:
    1. in any gear but let's say 3rd gear, I downshift into 3rd to decel, I let off the throttle aroudn 3000 rpm, i let it slow down to 1500 rpm, i clutch in , it wants to stall.. it just goes all the way to 700 rpm or so before even trying to catch and it doesn't do anything in between.

    Is easily repeatable by letting off the throttle for 5 seconds or so in any gear (above 15mph now) and then clutching in.
    What I think is happening here is since i let off the throttle for 5 seconds or more, the throttle follower is already 0 so it doesn't come into effect at all (and tuning changes to it seem to have 0 affect so that validates my theory).
    Since the follower is 0, AND since my adaptive idle is < 15 mph, the ECM isn't using the follower tables or the adaptive idle tables in this scenario and wants to stall. So the question is WHAT is it using?? I assume the base airflow table and I've been inching that up, but it only needs 9g/s to idle and it looks like im going to need 12g/s+ in that table to keep it from wanting to stall. It does seem that this is the only table it references at that point, very odd.
    Any problems with simply putting the adaptive idle speed at some unobtainable mph?
    Any problems with putting the base airflow way more than I need? It still might not work right because the follower may reduce it more than what I put in the table which is where i'm seeing some odd results. Almost like there should be another table for idle airflow when not in adaptive idle and when follower is 0.
    Do you know what the follower max air limit is? also integral max air limit?
    I'll contact support and see if there's another table they can give me access to.
    Posted updated tune file.testing4-1.hpt

  4. #24
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    give this a test to see if it helps at all may or may not
    Attached Files Attached Files

  5. #25
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    Quote Originally Posted by smokeshow View Post
    Unfortunately it looks like you don't have the primary table available - the feed-forward throttle follower torque table where all of this calculation starts from.
    Quote Originally Posted by f00cts View Post
    Almost like there should be another table for idle airflow when not in adaptive idle and when follower is 0.
    Yes, that's what I mentioned above. You are only adjusting the throttle follower filters...not the follower airflow itself.

    TF manages the transition from on-pedal to idle and vice versa. A different cam requires changes to this table to prevent idle dips and stalls. Follower max air limit probably won't help because its the initial torque value thats too low And don't tweak the idle airflow limits too much...leave them alone unless you know what you're doing. You'll get integral windup and it'll make you pull your hair out if you know know whats going on.

  6. #26
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    Quote Originally Posted by 07GTS View Post
    give this a test to see if it helps at all may or may not
    tried this but it makes it oscillate a lot even at normal idling not moving. I didn't even try driving it because idling especially with the ac on it was oscillating a ton an stabbing throttle made it stall on the way back down.

  7. #27
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    Quote Originally Posted by f00cts View Post
    tried this but it makes it oscillate a lot even at normal idling not moving. I didn't even try driving it because idling especially with the ac on it was oscillating a ton an stabbing throttle made it stall on the way back down.
    ok if that was worse then try this its more in the opposite way see if that makes any difference, such a pain without that torque follower table
    Attached Files Attached Files

  8. #28
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    OK I'll try it.. I noticed before you adjusted the integral airflow limits and the spark table but this time you didn't.. Maybe one of those was interfering with it also ?

  9. #29
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    I suppose shooting from the hip works sometimes. Why do I bother

  10. #30
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    Quote Originally Posted by f00cts View Post
    OK I'll try it.. I noticed before you adjusted the integral airflow limits and the spark table but this time you didn't.. Maybe one of those was interfering with it also ?
    yea trying to make less changes to keep track of whats working or not, mainly trying the torque adjustments as adding a camshaft changes the map reading for idle so that changes the torque reading at idle for any torque based corrections to control, easy test to see if any of that works or not then if not can move on to other areas

  11. #31
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    Quote Originally Posted by smokeshow View Post
    Yes, that's what I mentioned above. You are only adjusting the throttle follower filters...not the follower airflow itself.

    TF manages the transition from on-pedal to idle and vice versa. A different cam requires changes to this table to prevent idle dips and stalls. Follower max air limit probably won't help because its the initial torque value thats too low And don't tweak the idle airflow limits too much...leave them alone unless you know what you're doing. You'll get integral windup and it'll make you pull your hair out if you know know whats going on.
    Heh yeah I knew there was something missing. What exactly does this table do and when I open a ticket with hptuners what table am I asking them for?
    I have a feeling i can trick it to work possibly by making the base airflow much higher but i'm not sure if that will create other issues. Aside from that sometimes it works one day and not the next day , like it will drive fine one day and then stall next day, which also makes no sense.

    Anyway I did open a request with them and attached the tune file and asked for throttle follower initial torque table, so I hope that was it. (ECM 12123)
    Last edited by f00cts; 04-09-2021 at 09:12 PM.

  12. #32
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    Looks like that table doesn't exist in my ECM according to hptuners support, and I have to mess with the torque model stuff like 07GTS did. I'm still working with them but it might not be possible.
    I'm getting tired of the massive fuel smell as well. Still trying to figure out how to stop it from being so rich.
    It's so rich my oil is full of gasoline, even smells like gas and is way more viscous than it should be from being mixed with the gasoline. Time to pop out the injectors and see if something is leaking ugh

  13. #33
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    Quote Originally Posted by 07GTS View Post
    ok if that was worse then try this its more in the opposite way see if that makes any difference, such a pain without that torque follower table
    Tried this and made 0 difference that I can tell. I'm thinking it might have been one of the other changes you made in the other file which made it oscillate so much, maybe the airflow limits?
    It still oscillates more than It should with this current file..
    Seems like it changes though, I can flash in something and it works great for a day or two and then all of a sudden it's crappy again.
    I think this ECM is just horrible, and my best bet is to drop in a haltech or something of the sort

  14. #34
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    Quote Originally Posted by f00cts View Post
    Tried this and made 0 difference that I can tell. I'm thinking it might have been one of the other changes you made in the other file which made it oscillate so much, maybe the airflow limits?
    It still oscillates more than It should with this current file..
    Seems like it changes though, I can flash in something and it works great for a day or two and then all of a sudden it's crappy again.
    I think this ECM is just horrible, and my best bet is to drop in a haltech or something of the sort
    even try the first one with just the torque changes and not the airflow limits encase the limits screwed it up, those limits can do wonders but only if they are exactly right

  15. #35
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    Quote Originally Posted by 07GTS View Post
    even try the first one with just the torque changes and not the airflow limits encase the limits screwed it up, those limits can do wonders but only if they are exactly right
    Tried it, and no real noticeable changes..

    Pretty much done messing with it at this point, has been years of nothing but headaches. I guess the key to tuning something is to use an aftermarket ECM, or make sure what you are doing is compatible with the stock one (i.e. most likely if i didn't have a super light rotating assembly an clutch it wouldn't be a big deal)

    Going to wire up my haltech from my other car to it and see how it runs , if it's good and does what i want then only problem is making sure the actual car stuff still works (dashboard stuff, cruise control etc)

  16. #36
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    Quote Originally Posted by f00cts View Post
    Tried it, and no real noticeable changes..

    Pretty much done messing with it at this point, has been years of nothing but headaches. I guess the key to tuning something is to use an aftermarket ECM, or make sure what you are doing is compatible with the stock one (i.e. most likely if i didn't have a super light rotating assembly an clutch it wouldn't be a big deal)

    Going to wire up my haltech from my other car to it and see how it runs , if it's good and does what i want then only problem is making sure the actual car stuff still works (dashboard stuff, cruise control etc)
    Because I was curious myself and also felt a bit bad for you lol, I dug the table out of the hex with user defined parameters. I'm betting HPT said it doesn't exist because it appears to be before the throttle follower was broken down by gear. Just looked like two rows indicating D/R and P/N rather than 6 forward gear, reverse and park/neutral. This is what I found...

    06 CTS-V TF.PNG

    Edits that I might make to try to fix the issue...

    06 CTS-V TF edit.PNG

    Unfortunately I don't have the new cable yet and can't save the file without licensing it. Templates also don't work for user defined parameters. If you have user defined parameters I can give you the memory location for this table.

  17. #37
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    Holy f@ck, didn't know you could do that. How cool is that. Always wondered how powerful user defined parameters were... How does one get started in digging through to find these things? Just a memory dump and a bit of inside knowledge or is there a bit more available to give half Joe a chance?

    That HPT support person needs a kick up the ass if it was said this table didn't exist.