EBL Acceleration Enrichment with 3500 stall converter
#1
EBL Acceleration Enrichment with 3500 stall converter
EBL Flash II. 86 305 TPI, Stock with headers and high stall converter.
When I stab the throttle - from a lower RPM such as 900, my wideband will go rich (often as rich as 8 or 10), then it will swing way lean - 20:1 or more at times. It seems that my AE is too aggressive but too short. In my datalogs I see both TPS and MAP AE being added, which brings the AFR way down to the 8-10's, and then the AE stops, and the AFR climbs up to 18+ then settles back to 14.
I read through the information on the AE tables, and although there are supposed to be adjustments made for different sized injectors, all the sample tunes have the same AE tables regardless of 19 or 22 lb injectors. I'm running Bosch III 24's with my BPC set to 161
It seems to me that due to the high stall converter, my RPM's climb higher and more rapidly than a stock setup and that may be what's leading to this effect.
It seems like I need to lower the size of the AE, but extend the duration - it's too rich too quickly but doesn't last long enough. So should I lower the AE pulse width tables, and also lower the filter tables to shrink the size but extend the duration? I've tried some small changes to the filter tables with no perceptible effect. The numbers in the table are already pretty low - in the 20's and 30's. I'm not sure how much of a change I should try here.
When I stab the throttle what should I be looking for on the wideband? I understand it should richen up, but 8-10 AFR seems likely too rich. And it doesn't seem like 18 would be acceptable under load. What should I aim to keep the AFR at during the AE event? I assume I want to see it go slightly richer like 12.5, and then climb back to 14.7 and stabilize?
I've included a datalog with multiple events. If you look around runtime 10:04 and 10:05 you will see what I mean.
Also - a related EBL question - when I'm looking at the datalogs etc, I see tpsAE and mapAE change to positive values and the AE changes to "Y", but the aePW value is ALWAYS 0.00 so I'm not sure what the aePW value is indicating or what that's telling me. I do see the AE box in the WUD change to green when I get on the throttle - but in the logs aePW is always zero. What is that parameter tracking?
GD
When I stab the throttle - from a lower RPM such as 900, my wideband will go rich (often as rich as 8 or 10), then it will swing way lean - 20:1 or more at times. It seems that my AE is too aggressive but too short. In my datalogs I see both TPS and MAP AE being added, which brings the AFR way down to the 8-10's, and then the AE stops, and the AFR climbs up to 18+ then settles back to 14.
I read through the information on the AE tables, and although there are supposed to be adjustments made for different sized injectors, all the sample tunes have the same AE tables regardless of 19 or 22 lb injectors. I'm running Bosch III 24's with my BPC set to 161
It seems to me that due to the high stall converter, my RPM's climb higher and more rapidly than a stock setup and that may be what's leading to this effect.
It seems like I need to lower the size of the AE, but extend the duration - it's too rich too quickly but doesn't last long enough. So should I lower the AE pulse width tables, and also lower the filter tables to shrink the size but extend the duration? I've tried some small changes to the filter tables with no perceptible effect. The numbers in the table are already pretty low - in the 20's and 30's. I'm not sure how much of a change I should try here.
When I stab the throttle what should I be looking for on the wideband? I understand it should richen up, but 8-10 AFR seems likely too rich. And it doesn't seem like 18 would be acceptable under load. What should I aim to keep the AFR at during the AE event? I assume I want to see it go slightly richer like 12.5, and then climb back to 14.7 and stabilize?
I've included a datalog with multiple events. If you look around runtime 10:04 and 10:05 you will see what I mean.
Also - a related EBL question - when I'm looking at the datalogs etc, I see tpsAE and mapAE change to positive values and the AE changes to "Y", but the aePW value is ALWAYS 0.00 so I'm not sure what the aePW value is indicating or what that's telling me. I do see the AE box in the WUD change to green when I get on the throttle - but in the logs aePW is always zero. What is that parameter tracking?
GD
Last edited by GeneralDisorder; 07-13-2019 at 03:02 PM.
#2
Member
Re: EBL Acceleration Enrichment with 3500 stall converter
I would start by reducing the AE until it stops going rich. If it is too rich and stumbles, the miss fire will fool the o2 sensor so it reads lean even if it isn't.
#3
Re: EBL Acceleration Enrichment with 3500 stall converter
Thanks I'll make sure to do that first. Though I don't feel any misfire. Best to rule that out though - you're absolutely right it would drive the sensor lean. Someone else mentioned that to me also. Thanks for reinforcing the point.
What should I target for an AE air fuel ratio? Or should I only be trying to stop it from going lean?
GD
What should I target for an AE air fuel ratio? Or should I only be trying to stop it from going lean?
GD
#4
Re: EBL Acceleration Enrichment with 3500 stall converter
Not familiar with the EBL, but in 8D theres a switch called reset integrator when AE is active. It prevents the ECM from adjusting fueling when you're in a throttle transition.
Not sure if the EBL has that or something similar.
I found that without disabling the fuel trim during AE, I'd be chasing my tail with the ECM trying to "correct out" purposeful rich conditions during throttle transitions. When I finally discovered that switch and turned it on, the AE became much easier to tune.
Maybe that lean out you're seeing is the ECM reacting to the momentary rich condition? The longer the duration of the AE, the more time there would be for the ECM to "interfere" with AE fueling.
Not sure if the EBL has that or something similar.
I found that without disabling the fuel trim during AE, I'd be chasing my tail with the ECM trying to "correct out" purposeful rich conditions during throttle transitions. When I finally discovered that switch and turned it on, the AE became much easier to tune.
Maybe that lean out you're seeing is the ECM reacting to the momentary rich condition? The longer the duration of the AE, the more time there would be for the ECM to "interfere" with AE fueling.
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Re: EBL Acceleration Enrichment with 3500 stall converter
EBL Flash II. 86 305 TPI, Stock with headers and high stall converter.
When I stab the throttle - from a lower RPM such as 900, my wideband will go rich (often as rich as 8 or 10), then it will swing way lean - 20:1 or more at times. It seems that my AE is too aggressive but too short. In my datalogs I see both TPS and MAP AE being added, which brings the AFR way down to the 8-10's, and then the AE stops, and the AFR climbs up to 18+ then settles back to 14.
When I stab the throttle - from a lower RPM such as 900, my wideband will go rich (often as rich as 8 or 10), then it will swing way lean - 20:1 or more at times. It seems that my AE is too aggressive but too short. In my datalogs I see both TPS and MAP AE being added, which brings the AFR way down to the 8-10's, and then the AE stops, and the AFR climbs up to 18+ then settles back to 14.
Also - a related EBL question - when I'm looking at the datalogs etc, I see tpsAE and mapAE change to positive values and the AE changes to "Y", but the aePW value is ALWAYS 0.00 so I'm not sure what the aePW value is indicating or what that's telling me. I do see the AE box in the WUD change to
GD
GD
For the TPS based AE look at the aPW value. It is injected asynchronously so that there is immediate fuel.
Setting this flag will prevent the INT from changing (reset to 128) as long as AE is active:
Option Word 1 - Bit 5 - INTae
RBob.
#6
Re: EBL Acceleration Enrichment with 3500 stall converter
Excellent. Thank you! I have been reducing the AE - TPS PW. That is helping. I need to reduce it more.
And I think I need more MAP based AE - quite a bit more. Because it's always 0.0 in my datalogs. I'm going to increase the AE-MAP PW table quite a bit. I get a big shot of AE from the TPS (too much), then I can see the dMAP but it doesn't result in any aePW.
I will set that flag to reset the INT. That sounds like a good idea. And yes my throttle transitions are likely significantly different than stock due to the 3500 stall converter. My RPM drops a lot when I'm off the throttle and then when I'm back into the throttle it has to climb sometimes 1000 to 1500 RPM to bring the converter back up to speed. It's very drive-able and you really can't feel these rich and lean conditions much but learning to tune them out is important to me.
GD
And I think I need more MAP based AE - quite a bit more. Because it's always 0.0 in my datalogs. I'm going to increase the AE-MAP PW table quite a bit. I get a big shot of AE from the TPS (too much), then I can see the dMAP but it doesn't result in any aePW.
I will set that flag to reset the INT. That sounds like a good idea. And yes my throttle transitions are likely significantly different than stock due to the 3500 stall converter. My RPM drops a lot when I'm off the throttle and then when I'm back into the throttle it has to climb sometimes 1000 to 1500 RPM to bring the converter back up to speed. It's very drive-able and you really can't feel these rich and lean conditions much but learning to tune them out is important to me.
GD
Last edited by GeneralDisorder; 07-14-2019 at 07:22 PM.
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#8
Re: EBL Acceleration Enrichment with 3500 stall converter
Ok. To close out this thread if anyone runs across this:
After talking to RBob it was found that there was a small bug in the EBL firmware that causes the aePW to be zeroed out anytime the TPS AE is set to asynchronous (required for port injection). So that made it impossible to use MAP based AE on port injected (TPI) applications.
For now - contact RBob if you need to use this feature. The bug has been fixed but the new version of the firmware is still considered to be in testing as of this post's date.
GD
After talking to RBob it was found that there was a small bug in the EBL firmware that causes the aePW to be zeroed out anytime the TPS AE is set to asynchronous (required for port injection). So that made it impossible to use MAP based AE on port injected (TPI) applications.
For now - contact RBob if you need to use this feature. The bug has been fixed but the new version of the firmware is still considered to be in testing as of this post's date.
GD
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