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I like using it, some people don't like using it. Whenever your car is going lean is normally where over-run fuel cut would kick in and fully cut fuel, due to the 3 second delay it sweeps the 20 kPA vacuum line and references those cells for fuel. Using the Idle VE Table probably wouldn't help as it would still be in the normal VE table still where your AFR goes over/under 14.7. My advice would be to get it a little richer than 14.7 and let it be, it won't hurt anything not being at exactly 14.7 for a few seconds on throttle lift.
I like using it, some people don't like using it. Whenever your car is going lean is normally where over-run fuel cut would kick in and fully cut fuel, due to the 3 second delay it sweeps the 20 kPA vacuum line and references those cells for fuel. Using the Idle VE Table probably wouldn't help as it would still be in the normal VE table still where your AFR goes over/under 14.7. My advice would be to get it a little richer than 14.7 and let it be, it won't hurt anything not being at exactly 14.7 for a few seconds on throttle lift.
Okay thanks! So I’m currently idling around 14.2 to 14.4 AFR due to trying to mitigate the lean condition that is causing my RPM dip. Is that fine as well? Sorry if I misunderstood what you were trying to say!
It just seems the closer I get to 14.7 at idle, the more likely it is I will get that RPM dip for some reason.
Yeah that's fine, I have 15% EGO at idle and my idle VE is normally around 14.2-14.4, with EGO pulling fuel til I hit 14.7 after it sits at idle for a few seconds.
Yeah that's fine, I have 15% EGO at idle and my idle VE is normally around 14.2-14.4, with EGO pulling fuel til I hit 14.7 after it sits at idle for a few seconds.
Awesome thanks! I'll do a bit more tuning and see how it goes! I will let you know if I get hung up, thank you!
I think I may have to play around with my EGO control a bit. I have noticed recently that after the car has been sitting for awhile, and then I start driving it, the AFRs are VERY jumpy and the car is a bit jerky at acceleration and cruise. This seems to happen for anywhere from 5-10 minutes of driving, and then everything smooths out. Its kind of weird that it does that, so I took a log and video of the condition. From what I'm thinking, it must be the EGO control, but I could be wrong. I've attached a data log I took of the condition, my tune, and here is a video:
I don't think its EGO, it looks like the car stutters when its between these 4 VE values, they are pretty far apart and the difference between the two values seems great enough that the car stutters. Try tuning that part of the 30 kPA column by hand, I would suggest putting them 1-3 VE below the 40 kPA Column.
Try something like this instead, I suspect it will stop stuttering. Keep autotuning your VE Table and hand tuning the cells under 40 kPA that aren't touched by VEAL.
I don't think its EGO, it looks like the car stutters when its between these 4 VE values, they are pretty far apart and the difference between the two values seems great enough that the car stutters. Try tuning that part of the 30 kPA column by hand, I would suggest putting them 1-3 VE below the 40 kPA Column.
Try something like this instead, I suspect it will stop stuttering. Keep autotuning your VE Table and hand tuning the cells under 40 kPA that aren't touched by VEAL.
Ahh okay thank you! I will make those changes and see how it goes. I will probably do this on Friday after these tropical rainstorms pass by.
I made the changes that you recommended, and it looks like around there the jerkiness has stopped! So thank you! However, now I'm getting jerkiness across other parts of the fuel table along with a rapidly fluctuating AFR reading. I did run VEAL, and it seemed to help somewhat, so I may just need to do some more VEAL tuning to get that sorted? I will have to see how it behaves after sitting overnight as well. One thing I did notice is that now going into overrun, the car jerks/bucks slightly, but the bigger issue is coming out of overrun. When I apply throttle coming out of overrun, particularly light throttle, the car jerks quite a bit. I'm thinking it may have something to do with my bottom row of my fuel VE table being 34 due to me being a ricer and wanting some popping noises, but I'm not entirely sure. I'm not sure what is causing that, but I did take a datalog of my drive today. I will upload that along with my tune! Any guidance would be appreciated.
If you want to have your lower row really lean, make the row above it closer to it in kPA so you don't hit it while cruising (it looks like your car will sit between 30 kPA and 20 kPA so it interpolates between the two rows and leans way out when you are cruising and the issue is the same as the previous fuel cells causing jerking)
To fix, change the row above 20 kPA to 25 kPA instead of 30 and your jerkiness will probably stop. My VE Cells go from 13 > 19 > 25 so even if I cruise at a really low kPA I don't ever interpolate into my 30 VE cells at the bottom.
If you want to have your lower row really lean, make the row above it closer to it in kPA so you don't hit it while cruising (it looks like your car will sit between 30 kPA and 20 kPA so it interpolates between the two rows and leans way out when you are cruising and the issue is the same as the previous fuel cells causing jerking)
To fix, change the row above 20 kPA to 25 kPA instead of 30 and your jerkiness will probably stop. My VE Cells go from 13 > 19 > 25 so even if I cruise at a really low kPA I don't ever interpolate into my 30 VE cells at the bottom.
Gotcha, thank you! I will give that a try. Would you recommend I interpolate all through the kPa range after making the change to 25? Just asking because I will have to then find a way to keep the top at 220 kPa due to going to boost later on. And of course, I will have to retune the whole fuel table after.
I would probably just change the 30 y axis straight to 25 and pull like 1-3 VE from the entire row and see how the fueling at cruise looks, then adjust from there
I would probably just change the 30 y axis straight to 25 and pull like 1-3 VE from the entire row and see how the fueling at cruise looks, then adjust from there
Thank you! I did that and the car improved a bit, but still wasn't quite right. I was trying to use VEAL to get some of the cells, but it didn't seem to act correctly based on what I was experiencing. So, what I did was I started to hand tune the cells where I was still having some issues. I also noticed that my car really did not like the bottom cells to be as lean as they were, so I richened them up. That helped smooth it out a bit more. Unfortunately, no more popping for me...kinda bummed about that. The fuel table is nowhere near perfect though. I'm not sure why my car is such a bear to get tuned correctly. I'll upload my tune and a datalog from today. What I did is that was hand tuning mostly the cells in the 2000 RPM to 3700 RPM area between 50kPa and 70 kPa. I'm still getting some jerkiness and irratic AFRs. For example, in the datalog, between 2835.058 seconds and 2836.530 seconds, you can see my AFRs lean out to 15.8 and fluctuate while accelerating from 2618 RPM to 3447 RPM. Not sure what is causing that, unless its just a fuel tuning issue. You can also see which cells I have locked out for VEAL I believe under the VEAL tab. Also still pretty rough coming out of overrun.
Thanks for any help you can give me! I was thinking of backing up this tune file and taking a datalog then running VE Analyze in megalogviewer just to see what it comes up with and giving that a try as well.
Here's why, I think I missed this earlier. It isn't the lower load cells (although changing the 30 kPA to 25 kPA is a good idea) (you can bring back exhaust popping), your VVT PID settings are FUBAR and the car is oscillating/hacksawing around the target super bad and it never holds target, even with a constant RPM.
You could try tuning this the way you typically do, however your current PID settings are so bad I think anything different would work better than your current values.
Try these, they seem to work well on many VVT cars (MS3 Basic Basemap values). Pretty sure the PID algo is the same for you as it is for me on an older firmware.
Here's why, I think I missed this earlier. It isn't the lower load cells (although changing the 30 kPA to 25 kPA is a good idea) (you can bring back exhaust popping), your VVT PID settings are FUBAR and the car is oscillating/hacksawing around the target super bad and it never holds target, even with a constant RPM.
You could try tuning this the way you typically do, however your current PID settings are so bad I think anything different would work better than your current values.
Try these, they seem to work well on many VVT cars (MS3 Basic Basemap values). Pretty sure the PID algo is the same for you as it is for me on an older firmware.
Ahh okay thank you very much! I will try those values in the VVT PID settings and see how it goes. VVT keeps coming back for more it seems. I'll try that and do some more fuel tuning, see how it goes and let you know, thank you!
Here's why, I think I missed this earlier. It isn't the lower load cells (although changing the 30 kPA to 25 kPA is a good idea) (you can bring back exhaust popping), your VVT PID settings are FUBAR and the car is oscillating/hacksawing around the target super bad and it never holds target, even with a constant RPM.
You could try tuning this the way you typically do, however your current PID settings are so bad I think anything different would work better than your current values.
Try these, they seem to work well on many VVT cars (MS3 Basic Basemap values). Pretty sure the PID algo is the same for you as it is for me on an older firmware.
So I used these settings today while I went out to tune, and I definitely think the car smoothed out a bit! I did notice that the car leans out when giving it throttle while accelerating, and the AFRs seem to fluctuate for a second or two before evening out again. This can be seen in the log from 92.261 seconds to 106.860 seconds. I'm not sure if that is just a fueling issue with the fuel table, accel enrich, or if VVT is doing something to cause that there as well.
I also noticed it is still a bit jerky on the throttle while exiting overrun. Its not nearly as bad as it was before, but its definitely still noticeable enough that I would like to see if there is something I can do about it. That same time interval I mentioned above, is where I got a bit of jerkiness; when looking at the fuel table, the circle with the dot in it kind of goes in a zig-zag motion, which I suspect is causing that jerkiness. You can also see that behavior exhibited from 146.441 seconds to 150.000 seconds when you load my fuel table in megalogviewer. Thanks for any help you can give me, I appreciate it!
All of your previous autotuning is basically worthless with how bad your VVT was at hitting target, I am pretty sure running more autotuning will fix your fuel table issues you seem to experience. Stumbling when exiting over-run sounds like it might be your acceleration enrichment or your over-run fuel cut re-engagement settings, your AE adds a lot of fuel and you could try cutting the amount of fuel by a ton and seeing how that works, could be getting too rich and stumbling. Something like this might work.
VVT Target VS Actual now seems perfect on that log, so the PID settings seem great.
All of your previous autotuning is basically worthless with how bad your VVT was at hitting target, I am pretty sure running more autotuning will fix your fuel table issues you seem to experience. Stumbling when exiting over-run sounds like it might be your acceleration enrichment or your over-run fuel cut re-engagement settings, your AE adds a lot of fuel and you could try cutting the amount of fuel by a ton and seeing how that works, could be getting too rich and stumbling. Something like this might work.
VVT Target VS Actual now seems perfect on that log, so the PID settings seem great.
Awesome, thank you! I’ll give those a try. Although, I do remember trying lower values for my AE before, and the car would basically act like it cut all fuel, the AFRs would lean out to 22.0 and then it would rev up high after that stumble. Maybe I had the values too low when that happened.
I gave those settings a try for AE, and my car did not like it at all. :( It would go stumble, go full lean, and then rev up. I also tried my current settings, which are also not ideal. I tried playing around with the values, but couldn't get anything that really worked very well. I have attached the two logs; one with my current settings and one with the new settings you recommended. Anything you can think of that may help with that?
Not every car is the same, I guess yours wants lots of AE, that's fine. Just wanted to see if anything with a little less fuel worked.
May just want to work on smoothing out your fuel map to see if smoothing it out improves drivability, issue probably doesn't lie in AE.
Something to possibly look at, your lag factors for the TPS signal seem a bit high, maybe try less smoothing on that so the MS picks up the TPS signal sooner (i think that's how that works?)
My settings are on the right, try out just the TPS Lag factor maybe?
Not every car is the same, I guess yours wants lots of AE, that's fine. Just wanted to see if anything with a little less fuel worked.
May just want to work on smoothing out your fuel map to see if smoothing it out improves drivability, issue probably doesn't lie in AE.
Something to possibly look at, your lag factors for the TPS signal seem a bit high, maybe try less smoothing on that so the MS picks up the TPS signal sooner (i think that's how that works?)
My settings are on the right, try out just the TPS Lag factor maybe?
Cool thank you! Yeah for some reason my car wants more fuel...weird, but I can live with it. I will try smoothing out the fuel table as well as the TPS lag factor and see how that goes. When do you think would be a good time to install the larger injectors? Just wondering since winter is coming very soon and I wouldn’t have the ability to tune my fuel table during the winter since there will be salt on the ground (trying to preserve the car as best as possible). The plan is to throw the turbo parts on over the winter, so just curious if I’m going to have any issues doing that.
11-09-2020, 02:11 PM
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