Guys,
My $E6 '8625 uses a n Accel Enrichment table called "AE Sync Pulse Width Correction Vs RPM" .. Can anyone explain what this does? I was under the impression that AE was Async.. Confused
TIA,
Ben.

 

As I read it, that would be you AE correction vs RPM. At lower engine speeds you need more AE, to cover the *hole* to get to PE.

If it uses a decay the numbers will decrease as the RPM rise.

Mess with the numbers and see what happens. With AE a big change, and one blip of the throttle will tell you which way you want, or if it matters. Without source code, you can't tell what's really in use. Some codes have some tables/ entries, that aren't mentioned in the code. The injector constant for the 58 being one of them.

 

Thanks Grumpy, that clears it up quite a bit. I'll have a play with it.

 

It must be the same as the "Diff MAP AE Correction vs RPM" table that is in the $0D, $0E, and $31 masks for the 16197427 which is almost exactly like the '8625. TPS AE lasts only about .1 seconds as I mentioned in your other post so it must be for MAP AE. The hacks are full of confusing and incorrect descriptions, or so I have found. HTH

 

Is ther anything like this in $42. I've looked through the hack till I went cross eyed and couldn't come up with anything. I guess I need to go start bugging the speed reader guys so I can get Rbob's badd asp tbi code.......I do have a spare ecm I could convert to romless.

 

I looked again after my eyes went back strait and I found this in the asdz hack.

;----------------------------------------------
; ASYNC MULT vs RPM TABLE
;
;
; THIS MULT IS USED TO CONVERT SMALL PW
; (PW/CYL)TO ASYNC (PW/12.5 Msec) INJ.
; FOR ASYNC INJECTIONS
;
;
; ASYNC IS BOTH INJECTORS, SYMO
; SYNC IS ATRNATING INJECTIONS
;
; FACTOR = (NUM CYLS/2) * (RPM/60) * (0.0125/2)
; .0125 = PULSE PERIOD, (80 Hz)
;
;
; TBL = MULT * 64
;----------------------------------------------
LD46B: FCB 8 ; 9 LINE TABLE
;
; MULT RPM
;----------------------------------
LD46C FCB 0 ; 0.000 0
LD46D FCB 21 ; 0.328 800
LD46E FCB 43 ; 0.672 1600
LD46F FCB 64 ; 1.000 2400
LD470 FCB 85 ; 1.328 3200
LD471 FCB 107 ; 1.672 4000
LD472 FCB 128 ; 2.000 4800
LD473 FCB 149 ; 2.328 5600
LD474 FCB 171 ; 2.672 6400
;----------------------------------------------

I'm guessing it's alot like or the same thing as the tables you guys are talking about. The thing that got me was the explanationf of sync and async in the comment. I didn't know that synce alternated injector firings and async fired both injectors. Does that sound correct? Also is this the table I need to play with to increase my pump shot at lower rpms and lessen it at higher rpm's? I thought that AE or pump shot was async so this would control that.

 

The 42 hac is about a decade old, alot has been learned since then.

Last I heard, Syn meant in sych with the DRP, and Asyn was a time based firing, ie 12.5 msec apart.

I believe the AE for the C3 TBIs, is an Asyn pulse. It's an time based pulse in additon to the sync pulses. I'd venture a guess that it's to get as much atomized fuel as possible.

 

I'm not sure that is the same table as the values seem reversed (see table below) and the table for the $0D, $0E, and $31 masks ends at 2800 RPM. To me, it looks like a table to handle the transition from synchronous pulses to asynchronous pulses which would explain the rising values as RPM increases. I could be wrong though. Can't hurt to play with it.

;---------------------------------------------
; ACELL ENRICH DIFF MAP CORRECTION FACTOR Vs. RPM
;
; Dissassemby of BDWM
;
; TBL = MULT * 128
;---------------------------------------------
ORG $4B9A ;
;
L4B9A FCB 128 ; 3200 UPPER TBL LMT
;
; MULT RPM
;---------------------------------
L4B9B FCB 215 ; 1.680 0
L4B9C FCB 144 ; 1.125 400
L4B9D FCB 107 ; 0.836 800
L4B9E FCB 78 ; 0.609 1200
L4B9F FCB 62 ; 0.484 1600
L4BA0 FCB 50 ; 0.391 2000
L4BA1 FCB 45 ; 0.352 2400
L4BA2 FCB 38 ; 0.297 2800
;---------------------------------------------

 

I increased the values in that table yesterday and it basically richened up my tune any tim I was in Asynch mode. I guess I could use it to dial back or up AE by moving this table then messing with my VE tables to get my AFR back to where I had it.

That brings me back to another problem or question I have been messing with. Where do you guys have your Synch to Asynch switch point set at? I'm using stock 454 settings and it throws the ecm for loops if I try anything else than those settings, but it seems like I'm in asynch alot.

 

That table is used to convert a sync PW to the equivalent amount of fuel in an async PW. It is only used when the normal fueling changes from sync mode to async mode due to short PW's. It is an RPM based table which should only be changed when changing the number of cylinders in the engine. It isn't used for the AE async PWs. Math wise the table is dead on, the problem is that the injector linearity isn't good enough.

I have given up on async mode fueling, both for the regular fuel and the AE fuel. There is a thread where I outlined the problems of async fueling. I have set the sync to async cutover PWs to 0 so there isn't any async fueling.

I re-coded the AE routine to change the AE fueling from async to sync. I also increased the injector bias to a value closer to the actual opening time.

RBob.

 

Rbob got me thinking about my Asynch settings again, I went back and reread some other post that I had printed out. Then it hit me, I was tuning my idle with my new WB and I was way lean, 15.5 to 17 and it was real jumpy and inconsitant. I started richening it up and within 2% VE change it jumped to 13 flat and was real smooth, I gained 5 KPA of vacume. I went back and hooked up winaldl, since my WB runs through my serial port I can't do both at once, and sure enough I was no longer in Asynch mode at idle. I ASSumed that since I was running big injectors at high pressure on a fairly mild motor that I needed Asynch to idle correctly.....wrong. So I went in and set my Asynch enable points back to the asdz settings, I had them set at the 454 settings, and sure enough I can now get a nice clean 14-1 idle.

Here's the other funny thing, I was badling a wicked lean spike off idle followed by my WB hitting rock bottom at 10-1 for a good second to second and half. I had quadroupled the TPS pump shot and cut the MAP pump shot in half and still had problems. Once the idle was in Synch mode and I had the TPS and MAP pump shots just slightly above stock settings my AFR is about perfect when I blip the throttle. My guess is I was using up all the available time at idle in Asynch mode so when I blipped the throttle I had no time left for AE, so I would get a lean spike then it would take a while to finally get all that extra fuel stored up "in the ecm" out into the motor.

My next step is to basically disable the asynch at idle by setting the enable PW to 0. Will I have any problems with this? Man this WB has been pricless. No way I would have figured this out without it.