Any one seen these DIY gauges?

[tasdrouille]

Ok, here's another question then. If get real time fuel consumption output from the ECU, how much more useful a SG would be?

[diesel_john]

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.

[cfg83]

diesel_john -

Originally Posted by diesel_john

I have a digital A/F meter that shows me the magic 14.7 number. I got it because I wanted to "see" what an EFIE (02 sensor signal modifier) would do. But, when the EFIE is off, the A/F ratio is pretty much bouncing above and below 14.7, so it's not doing much, just like you said.

CarloSW2
__________________
How does this EFIE work? What does the circuit look like? I once played around with the O2 voltage by just adding 0.2 of a volt to the signal with a 3v battery and a simple $5 voltage divider circuit and it gave me a mile per gallon or more. Did not check the placebo effect. Newer ECU's are harder to fool.
diesel

Here's mine :

Eagle Research EFIE Online ...
http://www.gassavers.org/showthread.php?t=5036

I will repost this as a thread in ecomodder so you can see the pictures, but this will get you started for now.

CarloSW2

[trebuchet03]

Originally Posted by diesel_john

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.

I'll test that... maybe this weekend, time permitting...

As for closed loop definitions.... There's more than one... There's also quasi closed loop states depending on the data coming in from different sensors....

The term "closed loop" in it's usage here is really a misnomer for feedback controls...

[Who]

Or the Compucruise - circa 1979

Functions: Speed, clock, alarm, cruise control, in/out temp, batt volt, trip, fuel consumption

[cfg83]

diesel_john -

Originally Posted by diesel_john

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

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

[diesel_john]

Originally Posted by Who

Or the Compucruise - circa 1979

Functions: Speed, clock, alarm, cruise control, in/out temp, batt volt, trip, fuel consumption

hey you found it, that part on the the left is just like the flow meter I had back in the '70's, that's the flow meter that i am trying to make over in the thread about measuring fuel flow on a carb'd engine.

[COMP]

any new info ????

[dcb]

Yah, john found his old flowmeter and is talking about it on this thread:

http://ecomodder.com/forum/showthrea...0293#post20293

[JohnnyGrey]

In regards to FE instrumentation, on a usefulness scale from 0 to 10, considering a scangauge being 10, how would you rate a combination of a/f ratio meter, closed loop monitor and vacuum gauge?

Narrowband AFR meters are completely worthless.

Wideband AFR meters are highly valuable if you know how to interpret and manipulate the output.

For a fuel meter, I'd rate the SG at a 7. The other things you mentioned, the SG already does, so there's not much need for discrete components.