The next things to take care of under fuel tuning is Acceleration Enrichment and Over-Run Fuel Cut, stay tuned... :)
Acceleration Enrichment - AE:
What is AE and why do we need it - and what is EAE... ?
AE is a function that takes care of fuel when you go from TPS 0% to TPS >0%.
Why is it needed ?
When the throttle is unpressed (TPS=0%~) and you press the throttle (TPS>0%~) you open the throttle body and let air in the manifold, the engine goes something like, "mmm OK, air is good but what about fuel.... mixxturree tooo leeeaaannnnn I CAN NOT RUN ! HELP !
Same happens when you start moving, shifting gears or just rev it.
What we want to do is, let MS know how much fuel to add (Pulsewidth added ms) when rapid change in TPS is sensed.
Picture:
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You can just try the settings in the pic.
Lets go over a few options:
- Accel Enrichment MAPdot<-->TPSdot Blend(%)
You choose if you want AE to work with MAP or TPS as guideline.
If your TPS is good and not too noisy - choose 100% TPS
- Accel TPSdot Threshold (%/s):
TPSdot = TPS + "dot" part is "derivative over time", speed of change.
The threshold is the point you want AE to kick in.
You can start with the second way I used to tune AE. (Scroll down a little)
You want to log the situations where your TPSdot makes you lean & impact drive-ability.
Static rev, gear shifting etc'.
In the log you will see what TPSdot level makes you lean.
These are the points you want to fix and let AE make them less lean - more rich.
You can see in my log:
TPS (green) going from 0% to 90% fast - around 200 %/sec TPSdot,
TPSdot - white
AFR (red) going lean 20:1- the spike
Tune the AE until it is not too lean or too rich, numbers aside, drive-ability is your first priority.
Even if the numbers are not perfect (never will be) and car's running smooth - stop right there !
EAE is Enhanced Acceleration Enrichment, it goes dipper into fuel AE management and is targeting low speed throttle movements with high resolution AE.
Haven't touched it yet, AE works good for me, but maybe some day....
Updated way to tune AE:
1. Zero out all AE "Added ms".
2. Set four TPSdot points. (slow tip, medium, faster and fastest)
3. Set a good TS dashboard to work with...
4. Start with idle rev, try to test the first TPSdot you set until you see the AFR not spiking (no 20:1, more like 14-16:1, no less)
5. move to the next TPSdot and repeat 4.
Set AFR as a "Line graph" under "Gauge style".
Helped me alot !
Turn off Over-Run Fuel Cut, when tuning AE !
Over-Run Fuel Cut
After I got AE tuned so good with Over-Run turned off, I need to look deeper into it before i turn it on again...
Wanna get better mileage ? good. Turn it on then,
Over-Run Fuel Cut: will shut off the fuel to the engine. tune it right and forget about it.
You can try my settings:
More to come...
Not sure if this is a double post or not..
ReplyDeleteI was wondering if you had any issues with the fuel returning after the Over-Run Cut turns off? From the indicator in TS I can see the overrun cut kick in and then go off but the fuel return does not come back on. Did you have that experience? Any ideas? Thanks!
You set the rpm you want the fuel to return... am I missing something ?
ReplyDeleteWhen it hits the rom my fuel does not return.
ReplyDeleteso your engine stall with no fuel down to 0 rpm ?
ReplyDeleteNo, interestingly enough it will run but AFR maxes out and acts like no power. I can pump the pedal and AFR will drop and then max out.
ReplyDeletetune your idle ?
ReplyDeleteCar is running great. Never enabled it. Saw your post and thought I would give it a try. Then had the problems so I disabled it.
ReplyDeleteIf it's working, don't fix it, when I changed to sequential injection I disabled AE, needed it only when was running batch.
ReplyDeleteWhat I wanted to implement was the overrun cut. Thought it might save some fuel. With sequential you do not need AE? I just bought the sequential module and want to add it this weekend. Any tips on the settings etc? Is it worth it? Can you send me your current msq? Thanks!
ReplyDeleteSorry I'm making a mess, overrun cut works, no problem can you log your problem ? send me the log.
ReplyDeleteAfter seq inj I disabled AE - for now I run great, after I will finish some other stuff, maybe I will fine tune it for my needs - buy I the ride is great.
I got a writeup about seq inj here - read it - if you need any help, talk to me.
YES IT IS WORTH IT.
Give me your email.
I did not know that the stock motors had it from factory. Had I known that I would have done it right away!. How do I send you my email without posting it in the blog?
ReplyDeleteelior77@gmail.com it is on the bottom of the page
DeleteYour Time-based AE/Decel Fuel Amount of 98% was an incredible change to my stock-internal NA 1.6. A value of 95% was extremely abrupt/jerky on-off throttle and really bothered me as I tuned my VE table and logged WOT runs on daily commutes...98% is OEM smooth.
ReplyDeleteThanks for documenting your thought process here and expanding on what Tunerstudio intends for these settings. It's giving me enough to keep moving forward in tuning my MS3X.
Cheers!