Accel Enrichment Tuning

[moonwell]

So I've got a bit of a stumble on tip-in, and I've finally got around to messing with the AE to try to fix this. According to my wideband, it shoots rich for a split second (~11-12:1), then goes way lean (19-20:1) So it would seem to me that the AE is too much initially, but it decays to quickly.

This is my OBD1 3400, tuning with Tuner Pro. In TP, I have the following AE tables available.

AE Async Pulse Multiplier Vs. Delta TPS
Accel Enrich Factor Vs. AE Pulse  
AE Async Pulse Multiplier Vs. Coolant Temp. 
AE Async Pulse Multiplier Vs. Baro     
AE Async Pulse Multiplier Vs. MAT

I've worked a bit with the "AE Async Pulse Multiplier Vs. Delta TPS" table. Increasing values in this causes to to go even richer and then not quite as lean. But it doesn't appear that there are any tables available to control the rate at which the AE decays.

in GMPCM, there are a few additional tables, so maybe those are what I need to mess with?

TIME-OUT REDUCTION FACTOR  
TIME-OUT REDUCTION FACTOR MULT

[sil]

have you tried 0-2 multiplier table ?

it is delta tps table

maybe try fiddlin with the 0 to 12.5 %Delta Tps mults


is this an idle "tap the throttle" and you get a stumble ?
or is it fine in idle?


man i had a bad stumble when i was using aubu on my df, switched to bhak and it dissapeared, didnt feel like ironing out the tip in stumble so i said f it and started tuning with the bhak

so im not too good at the stumble fixes
hopefully someone will chime in and help ya out


if its not in the a1.xdf heres the code

                                                 *##############################################################
                                                 *  F101B                                                      #
                                                 *  0-2 MULTIPLIER OF ASYNFACTOR VS. DELTATPS * 2              #
                                                 * TABLE VALUE = FACTOR * 128                                  #
                                                 *##############################################################
 * -------------------------------------------------------------------
 0AAD        60     96               0.75 MULT    0.00      %-DELTATPS
 0AAE        70    112              0.875 MULT    3.13
 0AAF        70    112              0.875 MULT    6.25
 0AB0        70    112              0.875 MULT    9.38
 0AB1        70    112              0.875 MULT   12.50
 0AB2        65    101               0.79 MULT   15.63
 0AB3        65    101               0.79 MULT   18.75
 0AB4        65    101               0.79 MULT   21.88
 0AB5        65    101               0.79 MULT   25.00
 0AB6        65    101               0.79 MULT   28.13
 0AB7        65    101               0.79 MULT   31.25
 0AB8        63     99               0.77 MULT   34.38
 0AB9        60     96               0.75 MULT   37.50
 0ABA        60     96               0.75 MULT   40.63
 0ABB        55     85              0.664 MULT   43.75
 0ABC        55     85              0.664 MULT   46.88
 0ABD        55     85              0.664 MULT   50.00

[moonwell]

have you tried 0-2 multiplier table ?

The 0-2 table is what is labled as the "AE Async Pulse Multiplier Vs. Delta TPS" in the A1 definition, so yeah, that is the table I have already been messing with. (The values in the table you posted actually match those shown in my screenshot right on). I have been making global adjustments to the table though, not adjusting just single cells.

is this an idle "tap the throttle" and you get a stumble ?
or is it fine in idle?

Tapping the throttle at idle, it doesn't really stumble, there is just a half second or so delay before it revs up. It shows the same rich-lean condition on the wideband as I get when rolling onto the throttle during cruise and between shifts though.

Thanks

[Syclone0044]

Brilliant post!! I have the exact same problems on my 1990 Turbo Grand Prix with the 8F code and upgraded from stock 22# injectors to 28# injectors. I have everything retuned beautifully but the tip in has a hesitation and I also suspected it was one of these 5 tables. I made adjustments to the "0-2 Multiplier" AE table and I must be missing something because while it does affect my issue, it doesn't affect it in the sense that I'd imagine. Reading your guys discussion gives me some ideas to try though. I think mine has the "idle rev hesitation" also.

Did you figure it out? I'd like to hear your thoughts.

Josh

[Mars]

Brilliant post!! I have the exact same problems on my 1990 Turbo Grand Prix with the 8F code and upgraded from stock 22# injectors to 28# injectors. I have everything retuned beautifully but the tip in has a hesitation and I also suspected it was one of these 5 tables. I made adjustments to the "0-2 Multiplier" AE table and I must be missing something because while it does affect my issue, it doesn't affect it in the sense that I'd imagine. Reading your guys discussion gives me some ideas to try though. I think mine has the "idle rev hesitation" also.

Did you figure it out? I'd like to hear your thoughts.

Josh

You are not using the same code mask as Moon, I doubt...

He is on A1, you should be 8F...

If you figure out the tip in hesitation, let me know... Mine goes tp 9:1 when you even tap the gas for a second. a second later it's back to 12:1 or 13:1 depending on what my RPM/boost is.

[Mars]

Alright, I figured out my pump shot.

AE Factor % vs. BPINJ Table.

It's an 8 bit table begining at 0A97.

I scaled all values by .75 - AWSOME, still rich.
I tried a tad more .65 - Better.
Then .55 and it's about perfect, car is SOOO smooth now, it's unreal. I can roll onto it as smooth as possible in 5th gear starting at 30 MPH. It's a beutiful thing.

It now shoots to 11:1 for an instant, then accels smooth.

HOWEVER this is with 30# injectors and a CENTRIFUGAL blower. I think with a turbo you'll want alot more pump shot, to get a nice rich burst of "heavy" rich exhaust air to get some spool...

This is $8F only. A1, I don't know.

[Syclone0044]

Thanks, Mars. I'll give it a try next time I burn a chip! I've never touched the AE Factor % vs. BPINJ Table before.

Josh