Timboj Posted January 31 Report Share Posted January 31 It's happened to me several times, but from memory it's only been while the car is still warming up to full operating temp. In this instance I was at 67/68C. My CLL kicks in at 50C. You can see that where I've stabbed the throttle quickly for a downshift, fuel correction seems to have switched off, fuel goes rich, the TPS starts bouncing all over the place and the exhaust sounds terrible. It takes a few pedal pushes to eventually snap it out of it. Any idea what the heck is happening here?? https://drive.google.com/file/d/1FSWBUUmnv4oldYTVPb7ZrL1og04n_zRb/view?usp=sharing https://drive.google.com/file/d/1MnxwbTUHz82Fb5drquz0V5QFy2D8cCRK/view?usp=sharing Quote Link to comment Share on other sites More sharing options...
Vaughan Posted January 31 Report Share Posted January 31 That's the E-Throttle struggling to get to the target position of 3.7% and oscillating around that point. You will need to adjust your PID values and maybe your feed forward table. Quote Link to comment Share on other sites More sharing options...
Timboj Posted January 31 Author Report Share Posted January 31 Sure, thanks Vaughan. Can you advise on why it's only happening under these specific conditions and not the other 99.9% of the time I'm driving? Quote Link to comment Share on other sites More sharing options...
Vaughan Posted January 31 Report Share Posted January 31 Probably because that is right by the neutral point that it is sprung to which will be the least stable point. You can use the PID Setup functionality to see how much each part of the PID loop contributes to the overall value. Timboj 1 Quote Link to comment Share on other sites More sharing options...
Adamw Posted January 31 Report Share Posted January 31 20 hours ago, Timboj said: You can see that where I've stabbed the throttle quickly for a downshift, fuel correction seems to have switched off, fuel goes rich, the TPS starts bouncing all over the place and the exhaust sounds terrible. It takes a few pedal pushes to eventually snap it out of it. And to cover a couple of the other points - CLL is disabled due to the TPS delta lockout, and the lambda goes rich because the throttle oscillation is continually activating accel fuel. Quote Link to comment Share on other sites More sharing options...
Timboj Posted January 31 Author Report Share Posted January 31 Makes sense. Thanks for the extra context, Adam. Quote Link to comment Share on other sites More sharing options...
Timboj Posted February 1 Author Report Share Posted February 1 So I've done another run with PID Setup on the eThrottle. How does one interpret this? By my eyes the feed forward looks fairly steady, as does integral. Do I read this that proportional/derivative need to be reduced? Edit- and is the correct approach to zero any feed forward and tune the PID first, then fine tune feed forward after? Another example, same settings: Quote Link to comment Share on other sites More sharing options...
Timboj Posted February 2 Author Report Share Posted February 2 Would you mind taking a look at this log/map? I zeroed the feed forward, played around with the PID and got it to what I thought was pretty good in terms of target v actual. Then after a short drive came the dreaded post-throttle blip oscillation. https://drive.google.com/file/d/11MtAY5lPMSPbg_iJAfugEA-mJ4K26KkW/view?usp=sharing https://drive.google.com/file/d/1ZE7bKd_CpzO-yhMLJBsafuclvRR5ehey/view?usp=sharing Is there something else going on here? This oscillation issue has only existed for me sometime in the last few months, and making any changes to feed forward was something fairly new to me too (previously 0), so I'm wondering if there is another value/setting that could be contributing? Quote Link to comment Share on other sites More sharing options...
Chocobuilt Posted March 31 Report Share Posted March 31 I am having this exact same issue. Same car. Same oscillating issue with the throttle blip. Did you ever figure out what the solution is? Quote Link to comment Share on other sites More sharing options...
Timboj Posted March 31 Author Report Share Posted March 31 After having the car off the road for nearly 6 weeks (more upgrades...) I've been for a few drives lately and haven't had the issue. Admittedly I haven't been trying to trigger this issue specifically. I rev match on my regular driving and it's been driving fine, but I'll test it a bit more aggressively today. Current settings on ethrottle, with feed forward still zeroed: Chocobuilt 1 Quote Link to comment Share on other sites More sharing options...
Chocobuilt Posted April 14 Report Share Posted April 14 I had some help from Adam with mine from the fb forum. i did adjust my feed table a bit but it was my PID settings. i am using P Gain 6.00 I Gain .100 and D Gain 60.00. and that settled it down a bit. haven't had the issue since i started using those. Timboj 1 Quote Link to comment Share on other sites More sharing options...
Timboj Posted April 14 Author Report Share Posted April 14 I noticed a touch of it today while I was driving (much less) so I'll give your settings a try and see if that makes a difference. Quote Link to comment Share on other sites More sharing options...
Timboj Posted April 20 Author Report Share Posted April 20 Can confirm that the combination of your suggested PID settings and the feed forward tweaking, it's working very well now. Cheers Chocobuilt 1 Quote Link to comment Share on other sites More sharing options...
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