I sent this to Gadget but never got a response. I guess he's staying pretty busy or it must be a really stupid question..

As you might remember, I have a 2000 4runner with all the fuel mods done to it. The only difference is that I'm tuning it with the S-AFC instead (Low set at 10%) and with the 305cc injectors.

I'm trying to tune my closed-loop with the OBII, but I'm having difficulties.

The short-term jumps from around -4 to +4 at various speeds when not in boost.

The long-term stays at -.8 at idle and at very little throttle. When I hit the gas some more it will gradually get more negative until I reach around 2000 RPMs. Then the long-term reads -20.3 and stays that way the more i hit the throttle (while still staying out of boost)


My low setting for the S-AFC is already at -10. Should i run it even leaner?
I am also confused as to which long-term reading should be at 0. At idle or when i give it a little gas? I always thought that the long-term should stay fairly constant..

thanks so much Gadget,
-Neil

 

bumping myself
Any help is appreciated
thank you

 

You can ignore STFT as that is for minute adjustments made constantly to keep things in check. What does the LTFT look like while you are at less than WOT with boost? If the LTFT is at 0% under boost while in Closed Loop, then the SAFC is tuned properly. If your LTFT is in the -% whnile under boost then yes, you need to lean out your SAFC. You really want to try for 0% LTFT under both conditions if you can, but if that's not possible, then run it so that under boost, LTFT is at 0 and ignore what it is under NA conditions while in Closed Loop.

I think the SAFC is going to severely limit your tuning ability. I don't think it has the resolution to do what you need to do. But, I could be wrong.

Post back with more info and I hope this helps.
G