RomRaider

Didn't know if anyone had discovered those on either the 16 bit or 32 bit ecus? Figured I'd ask. Thank you.

What function are you trying to descibe? What do you expect they will look like? What axes? What values? What does it do?

Well, I remember with the SAFC (very general here) for some types of setups there was a deceleration map adjustment to essentially adjust the fueling for deceleration situations. It may of been an RX-7 type thing. Didn't know if we even knew of any tables like that for the subarus.

Also, I would be unsure as to what they would look like. I dont know if it would just be a 2D table based on RPM value or what. But, nothing may exist for the injectors to add fuel while the throttle plate is closed.

Also maybe a cold start emissions function if it existed, but then again, I dont think it would make much sense.

Regardless, I'm crazy, but didnt know if it was something that existed.

I don't think what you describe exists. MAF is used for fueling. There is no real table that affects how much fuel is injected under decel conditions as far as I know. Normal OL/CL fueling would still apply as well.

The injectors do cut off completely if your input TPS is 0%, it has been 0% for about 1 second, and engine RPM is above about 1600rpm. I'm pretty sure there is a map for what RPM it will allow decel injector cut. I suppose there is also a 1D value for the delay, or maybe that is a 2D table depending on RPM. But you can't exactly tune the fueling.

I concurr with freon. There is a map of deceleration fuel cutoff. Its based on coolant temp. When the engine is cold it turns the injectors back on at a higher rpm, most likely to prevent stalling. And there must be a delay value referenced just for that because nothing we can tune with the current defs has any affect on decel fuel cutoff time.

Cool, thank you for your input. I appreciate it.

deceleration stuff is basically controlled via the idle routine.

if the car is in idle mode, and rpms > idle rpm, and rpms > fuel cutoff rpm, then idc = 0

idle mode is defined via tps, with an adjustable spread for IN and OUT to give some hysteresis.

idle rpm can be adjusted via the various 1d maps (normal, ac, high electrical load).

fuel cutoff rpm is a 2d map against ect, as mike describes.

there is also a 2x2 idle ign timing map that i've seen in other 16bit roms but have never uncovered in my own revision.

hth
ken

Thats an incorrect definition. That table has no affect on idle timing. Bill and I were playing with it a few months ago. Not sure if he's going to release the defs or not. Factory setting is locked in at 12 degrees timing while in idle mode, during fuel cut. When fueling resumes or is active in idle mode, the ECU will add or remove +- 8 degrees timing based on idle speed error. Lower rpm than desired, timing is added to the 12 degree base. Higher rpm than desired, timing sutracted from the 12 degree base. Also during idle mode, the IAC is working towards an opening amount that regulates idle speed with the least amount of timing correction. So compared to fueling, idle timing would be like "correction" and IAC duty would be like "learning" if that makes any sense.

interesting. i was always jealous of it. that is until i just used ECT to globally offset idle timing to where i wanted it to be.

i had found globally increasing advance helped stabilize the idle when using lean burn afrs, ie >15.5:1



that feedback loop using dynamic timing to stabilize the idle rpm can be adjusted, at least in terms of how much and how quickly it ramps up. it is defined as "ignition acceleration compensation" in my def.

i had played with it a while back to see if i could effectively create gear-dependent timing adjustments... ie, low gear, quick delta rpm = increased advance... high gear, slow delta rpm = decreased advance. i quickly discovered that my idle went to s*** and the timing at WOT didn't change at all.

I was jealous too, my def only has that table for the 2002 ROM (A4SGE01C) and I was running my stock revision 03 ROM (A4TC400L) so I had reflashed to the 02 rom which has totally different size timing tables and different logic here and there, and after totally re-tuning it, I realized that the definition didnt even do anything. Bill checked into it, and sure enough it was a dead table with logic that was disabled. The tables do exist, but they are 2d based on timing vs RPM, and they are all set at 12 degrees.

Yes, the 2x2 base timing table does nothing - it is left in there so they wouldn't have to recode because some non-USDM ECUs have two full-size base timing tables.