can i use 4 wire 02 sensors, or wide range a/f sensors to monitor a/f ratio on a carbed 350? if wired to a digital a/f ratio gauge will the gauge display what the sensors are reading, or will i need to monitor the sensors with a voltmeter?
CK5
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a/f ratio question
- Thread starter g_mo
- Start date
Thunder
3/4 ton status
Autometer makes AF ratio guages that work with any 02 sensor. Just plumb A 02 sensor in your exhaust pipe near the manifold hook it up to the guage as instructed and you are good to go. The heated 3 or 4 wire sensors give the best readings. But the guages will also work with single wire 02 sensors.
Wide band O2's are 0 to 5VDC, 'normal' O2's are 0 to 1 VDC. A gauge designed for a 'normal' O2 will be confused or even hurt by a wide band.
I think I posted it here a long time ago. Search O2 readers/gauges as I have a simple reader circuit that costs about $30 at RadioShack for the components.
I think I posted it here a long time ago. Search O2 readers/gauges as I have a simple reader circuit that costs about $30 at RadioShack for the components.
Mad-Dog
1/2 ton status
4 and 5 wire sensors are for wide-band applications (very expensive),
a simple 3-wire heated sensor will work fine for you.
heated sensors are far more accurate than non-heated sensors.
I use a Halmeter AF/30 unit with a 3-wire heated sensor (check out the web page for pics of the unit in dash.
It costs around $275 but it is very accurate, 3-wire sensors have 2 blacks and a white....the white is signal and the 2 blacks are for the heater which is bi-polar and does not care which of the blacks go to power or ground.
a simple 3-wire heated sensor will work fine for you.
heated sensors are far more accurate than non-heated sensors.
I use a Halmeter AF/30 unit with a 3-wire heated sensor (check out the web page for pics of the unit in dash.
It costs around $275 but it is very accurate, 3-wire sensors have 2 blacks and a white....the white is signal and the 2 blacks are for the heater which is bi-polar and does not care which of the blacks go to power or ground.
Mad-Dog
1/2 ton status
yes, with a wide-band decoder...
you don't need to spend that kinda money bro, forget the 4-wire sensors and keep it simple man.
a single wire sensor will work for you and it will help you calibrate the jetting just fine.
you don't need to spend that kinda money bro, forget the 4-wire sensors and keep it simple man.
a single wire sensor will work for you and it will help you calibrate the jetting just fine.
Triaged
1/2 ton status
All the wideband O2 sensors I have ever seen are 5-wire. To my knowlage there does not exist a 4-wire WBO2 sensor.
The 4 wires are:
Sense Cell Voltage
Sense Cell Ground
Heater +
Heater -
If you wanted something real simple you could just watch the voltage with a volt meter. Stoich. is around 450mV, lean is lower, & rich is higher.
ntsqd,
What did you do for a circuit?
The 4 wires are:
Sense Cell Voltage
Sense Cell Ground
Heater +
Heater -
If you wanted something real simple you could just watch the voltage with a volt meter. Stoich. is around 450mV, lean is lower, & rich is higher.
ntsqd,
What did you do for a circuit?
sled_dog
1 ton status
4 wire is just a grounded/heated O2 sensor. 5 wire is wide band.
A/F guages show what the sensor is reading.... sort of. They put the voltage into a LED display. My summit one cost like $20. I could have built one, and should have. Or just put a voltmeter on the output wire.
A/F guages show what the sensor is reading.... sort of. They put the voltage into a LED display. My summit one cost like $20. I could have built one, and should have. Or just put a voltmeter on the output wire.
Triaged said:
I was told that .7 to .75 is the leanest you want to be w/o a computer. Any closer to Stoich and it'll detonate too easily. The Lamba vs. Voltage curve of a narrow band O2 sensor is quite steep in that area.
I've built several of these readers, but I do not consider them anywhere close to equal to a Horiba (sp?) or similar tool. They do work well enough to get an idea of what's going on.
EDIT: Realized that this diagram is NFG unless you know something about the LED output. It is a ten segment LED assembly. When you're where you want to be (i.e. near Stoich) the first five segments will light up. It's been a while since I used mine, by I recall that richer = more lights. You can plug this in, in parallel, to a computer controled engine and watch the computer see-saw the A/F back and forth across the ideal.
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