Temporary Cheap Air/Fuel Gauge - TCCoA Forums
 
LinkBack Thread Tools
post #1 of 4 (permalink) Old 07-29-2008, 09:35 AM Thread Starter
Seasoned PostWhore
 
Join Date: Jul 2002
Location: Cullman, AL
Age: 56
Posts: 7,758
Send a message via AIM to 94 Daily Driven 4.6L
Temporary Cheap Air/Fuel Gauge

Simple question:

Would this cheapo Air/Fuel gauge:

http://store.summitracing.com/partde...5&autoview=sku

give me an accurate reading if I used a heated O2 sensor stuck up the tailpipe?

I just need something cheap and portable that I can use to tune my F100 and 73 Vert without having to do the ole "drive, read plugs, adjust carb, drive, read plugs, adjust carb, drive, read plugs ad nauseam..."

Everything I’m finding that uses the “in the tailpipe probe” is an exhaust gas analyzer and WAY more than I need.

I’m also open to suggestions!!

And as a second question: Can the heating element in a O2 sensor even be turned on and left on for an extended amount of time or will it burn out?

97 Lincoln Mark VIII LSC (Chip'd, 3.73 T/L... so far... )
97 Ford Aspire (Slow, but getting 36 mpg (f'n Ethenol!! )
84 F250 Dually w/6.9L Diesel (7.3L IDI pending)
73 Mercury Cougar Convertible w/351C 4V (Partially Restored)
69 F100 LWB w/460 Engine
76 Glastron Carlson 23' Jet Boat w/460 CJ Engine

Last edited by 94 Daily Driven 4.6L; 07-29-2008 at 10:18 AM.
94 Daily Driven 4.6L is offline  
Sponsored Links
Advertisement
 
post #2 of 4 (permalink) Old 08-03-2008, 11:07 PM
1st Gear Poster
 
buggzz's Avatar
 
Join Date: Sep 2002
Location: Thornton CO
Age: 49
Posts: 41
Send a message via AIM to buggzz
I am certainly not an expert, but here is my understanding of HEGO's.

Basically the sensor is either 0volts or 1.4 (or so) volts. and it toggles back and forth really quickly, making roughly a square wave. You would need some kind of circuit to integrate that squarewave to get a meaningful output.

Some cars have a wideband O2 sensor which gives a reading which is more or less analog.

So the normal HEGO sensor only gives either "too rich" or "too lean" information, and the wideband O2 sensor, which gives an analog reading.

I'd bet your gauge needs a wideband sensor. They are a lot more expensive.

_That_ is the sum total of everything I know about O2 sensors.

Ken T.
'97 Thunderbird LX, 4.6L V8 - The $300 wonder, 104K and running strong.
'93 Cougar, 3.8L V6, 186K - Dead from headgasket failure - RIP
'90 Bronco, 351W, 214K - The Hunting Rig
'01 Focus, 2.0L SFI DOHC, 108K - The Wife's Grocery Getter.
buggzz is offline  
post #3 of 4 (permalink) Old 08-03-2008, 11:14 PM
Moderator & Teksid Whore
Super Moderator
 
guitar maestro's Avatar
 
Join Date: Jul 2002
Location: Laredo, Texas
Age: 39
Posts: 11,961
Send a message via MSN to guitar maestro Send a message via Yahoo to guitar maestro
the one thing you can do with a narrowband O2 and that gauge, is tune for ONLY 14.64:1 A/F ratio.....when the HEGO output reads 0.45-0.50VDC, then that is stoich for gasoline.....above and below this voltage cannot and should not be extrapolated to determine any sort of "leanness" or "richness"...so technically, you dont even need that gauge....all you would need at least is a multimeter to monitor the voltage output of the O2

if you need some sacrificial O2s, i got my old bosch ones that i took out to replace with NTKs
guitar maestro is offline  
post #4 of 4 (permalink) Old 08-04-2008, 06:43 AM Thread Starter
Seasoned PostWhore
 
Join Date: Jul 2002
Location: Cullman, AL
Age: 56
Posts: 7,758
Send a message via AIM to 94 Daily Driven 4.6L
Quote:
Originally Posted by guitar maestro View Post
the one thing you can do with a narrowband O2 and that gauge, is tune for ONLY 14.64:1 A/F ratio.....when the HEGO output reads 0.45-0.50VDC, then that is stoich for gasoline.....above and below this voltage cannot and should not be extrapolated to determine any sort of "leanness" or "richness"...so technically, you don’t even need that gauge....all you would need at least is a multimeter to monitor the voltage output of the O2

If you need some sacrificial O2s, I got my old bosch ones that I took out to replace with NTKs
Yeah, that's all I wanting; just something to get me in the ballpark during cruise. And not have to weld in a bung on two vehicles that I’ll be changing the exhaust on in the future…

But my main concern is the location. Is the exhaust still hot enough for the O2 to read correctly if it is all the way in the back in the tailpipe? From http://www.asashop.org/autoinc/dec2002/mech.htm "572 degrees Fahrenheit to 680 degrees". And can the heater be turned on constantly or will it burn out.

Actually found the answer on the same page…
Quote:
Since OBD-II vehicles may have multiple oxygen sensors located some distance from the engine exhaust ports, these sensors are generally heated to speed the warm-up time period. The HO2S incorporates an internal electric heating element to bring the O2 sensor up to operating temperature quickly (under 35 seconds). Internal heating elements usually operate continuously while the engine is running to maintain an operating temperature of approximately 1292 degrees Fahrenheit to 1472 degrees Fahrenheit. Heated O2 sensors operate at a more consistent temperature and allow greater flexibility of placement locations in the exhaust system.
I’ll PM you about the O2. I have some but they all have 100K+ miles on them…

97 Lincoln Mark VIII LSC (Chip'd, 3.73 T/L... so far... )
97 Ford Aspire (Slow, but getting 36 mpg (f'n Ethenol!! )
84 F250 Dually w/6.9L Diesel (7.3L IDI pending)
73 Mercury Cougar Convertible w/351C 4V (Partially Restored)
69 F100 LWB w/460 Engine
76 Glastron Carlson 23' Jet Boat w/460 CJ Engine
94 Daily Driven 4.6L is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the TCCoA Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome