View Single Post
Old 03-06-2008, 06:43 PM   #16 (permalink)
cfg83
Pokémoderator
 
cfg83's Avatar
 
Join Date: Dec 2007
Location: Southern California
Posts: 5,864

1999 Saturn SW2 - '99 Saturn SW2 Wagon
Team Saturn
90 day: 40.49 mpg (US)
Thanks: 439
Thanked 532 Times in 358 Posts
diesel_john -

Quote:
Originally Posted by diesel_john View Post
if you throw a curve to the ecu and unplug a sensor how long does it take the
SG to report the glich? just for fun

i define closed loop to be when the oxygen sensor is fluctuating between .2 and .8 volts at least once per second. but the newer the engine the larger the number of sensors have to be in agreement before the ECU is truely in closed loop. as the technology got better the tolerance around .45 vdc has gotten smaller and smaller. so what is closed for a 91 engine doesn't cut it for a 2001 engine.
You can disconnect the 02 sensor. The car will stay in Open Loop, using the other sensors to decide how much fuel to put in. I hear this is called "limp mode", aka limp along until you get it fixed.

I think that the majority of cars have "narrow band" sensors ( 0 to 1 volt in a lambda shape, so the 14.7 "center point" is in a narrow region), like the one on my Saturn. However, if you install a fuel controller (or have a more advanced emissions system?), you will have a "wide band" 02 sensor (0 to 5 volts in a linear shape, so the 14.7 "center point" is wider and more accurate).

If I were ecomodding from scratch and knew what I was doing ahead of time, I might go for this :

AFC NEO (in the range of $400 - )
http://www.apexi-usa.com/product_ele...=260&pageNum=1

Quote:
The SAFC NEO marks the newest edition to the world famous Super AFC line of piggy back fuel controllers. Building upon the powerful SAFC II, the AFC NEO has taken piggy back style fuel control to a new level. The AFC NEO boasts an incredible 16 points of user definable fuel correction. VTEC control has also been incorporated for Honda/Acura applications. A complete monitor mode is also available to keep the driver/tuner informed of critical engine data.

Features include:

- Completely new case design
- Compact design
- Incorporates both AFC and VAFC functions in one unit
- 16 point fuel correction
- Color FED display
- User defined button and background colors
- Inverted "anti-glare" screen

Key functions include:

MONITOR MODE-
* RPM
* Throttle
* Battery voltage
* Correction %
* Air flow %
* Pressure
* Karmann
* VTEC

SETTING MODE-
* Air map
* Air map graph
* Throttle point
* Deceleration air
* VTEC control
* VTEC unmatch

ETC MODE-
* Model select
* Mode select
* Car select
* Sensor select
* Analog scale
* Warning set
* Display set
* Sensor check

It's a ton-o-cash, but it bypasses so many other flaky workarounds, and it looks like you wouldn't need a ScanGauge.

Hrmmmmmm, methinks the wide-band 02 sensor (+$100 or more) is extra, .

CarloSW2
__________________

What's your EPA MPG? Go Here and find out!
American Solar Energy Society
  Reply With Quote