I've been poking around with my SAFC now (S4 NA, no emissions), and I realized that I can pull 40% out at a 3000 RPM cruise before getting to a lean stumble! Is this normal? I know the ECU runs rich... but is it really that bad?

I have my oxygen sensor disconnected, so the ECU never goes into closed loop mode. However, I am monitoring the voltage on it through the SAFC, and I'm definitely well into lean territory (O2 pegged at 0.00v) when cruising.

Also, if I'm running this lean on the highway, should I be using more premix when I fill up to keep the same level of lubrication on the highway? I'm currently using ~100:1 (or slightly more oil).

Fuel economy numbers soon (mid-next week), but I can say that after going on a winding road cruise this morning, I definitely burned a lot less fuel than normal.

Would a CD ignition system's hotter spark delay the onset of lean stumble by providing a better ignition source?

-=Russ=-

 

I have mine set to -12% till about 4000. I have no wideband so i dont want to go any further.

 

I'm wondering about this myself... although the most I've run is -20%, I know my ECU is counter acting at least a little of that and running RICH because of the stupid water thermosensor wiring (I'm in need of replacing the wiring harness, eventually I'll get to it) so it thinks the car is always hot and tries to run rich to cool it down.

But how did you hook up the O2 sensor to the SAFC? I didn't see any directions in the SAFC on how to do that... or anything in the menus about an O2 sensor monitor? Except maybe sensor check mode...

--Gary

 

That's about it. I connected it to the blue wire, and can view the voltage from sensor check mode.

Also, I've gone back to around -20% or so - the engine would run just fine leaner, but I wasn't gaining any fuel economy - it was actually worse.

-=Russ=-

 

With an FD pump, I'm crusing at -24% between 2-3K.

 

can i hook my fd pump up now that i have a safcII going in tommorow? no other fuel mods yet btw.???

 

The FD pump makes very little difference in fuel delivery until you get into the higher boost & larger injector territory.

You can install them together or separately, in any order.

(You will like the S-AFC.)

 

I LOVE THE SAFC!!!! just different to get the hang of it. i will be boosting my n/a soon so when tank is low i'll throw in fd pump( just to get it out of the way). thanks.

 

i have about 28% out at 3k cruise. my 02 sensor is still connected, no idea if it still works or not. my highway mileage went up a lot (to about 25, from 20 or so), but my in-town mileage got screwed. i still have a lot to learn about this thing, obviously. 87 gxl