This is probably not the best place to put this post. . .but, hey, the question does apply to an Alto. . .
My RS-X runs a fairly early generation EFi setup which does not include an oxygen sensor in the exhaust. Now, seeing as how I'm going to do a fair bit of 'home' modification to this motor, I wanted to install a setup so that I could keep an eye on the air/fuel ratio. To this end, I've welded a nut onto the exhaust, as close to the turbo outlet as possible so that I can fit an oxygen probe, and I've constructed a cheapo 'mixture meter' kit from Jaycar.
The probe I initially used was a single wire unit (from a '89 GTi Swift). This did not work well. . .I think because the probe is too far from the turbo and doesn't stay hot enough to work properly.
So, now I've got an internally heated, three-wire probe from a VL Commonwhore. . .red, black and white wires. White wire is output and red and black run the heater.
Now (after that huge explanation), does anyone know if oxygen probe internal heaters run constantly, or are they thermostated somehow? I was simply planning to power the heater from the ignition via a relay. . .I assume this is how they would run in order to keep the temperature as constant as possible but I don't particularly want to burn the probe out if I'm wrong. . . .
Anyone got any ideas?
Thanks, as always,
Pete in Perth
Oxygen sensors
Given that the heated O2 sensor is designed to get up to operating temperature faster than a conventional sensor I'd assume that it is just constantly heated from the 12v ignition power.
The majority of sensors won't work properly until they get to something like 350 degrees celcius, so I'd be looking at your voltage levels on the GTi sensor when you've run the car up to operating temp for a few minutes.
The voltage should be crossing backwards and forwards over .45v if the sensor is working correctly.
The majority of sensors won't work properly until they get to something like 350 degrees celcius, so I'd be looking at your voltage levels on the GTi sensor when you've run the car up to operating temp for a few minutes.
The voltage should be crossing backwards and forwards over .45v if the sensor is working correctly.
F8B EFI turbo - Three pots and a snail.
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Almost a Mini
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Brayden wrote:
The majority of sensors won't work properly until they get to something like 350 degrees celcius, so I'd be looking at your voltage levels on the GTi sensor when you've run the car up to operating temp for a few minutes.
The voltage should be crossing backwards and forwards over .45v if the sensor is working correctly.
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Yeah, I think they need almost 400 degrees as far as I know. I think that's at least part of the reason why the single wire GTi sensor isn't working properly - it's a bit too low in the exhaust and stays a bit cool. Even after a good, hard run, I couldn't get voltages up much above 0.1V. The GTi sensor had also seen a fair bit of action - the car it came out of had done almost 300,000km. . . .
With the injection setup the RS-X has, I don't think I will get a rich/lean cycle. . .as I said in my first post, the '87 Alto's don't run an oxygen sensor as standard, so I assume mixtures are always set off the base maps in the ECU. . .I would expect this to lead to a steady (maybe 0.5-ish volts?) at idle.
Thanks for your help.
Pete in Perth
The majority of sensors won't work properly until they get to something like 350 degrees celcius, so I'd be looking at your voltage levels on the GTi sensor when you've run the car up to operating temp for a few minutes.
The voltage should be crossing backwards and forwards over .45v if the sensor is working correctly.
_______________________________
Yeah, I think they need almost 400 degrees as far as I know. I think that's at least part of the reason why the single wire GTi sensor isn't working properly - it's a bit too low in the exhaust and stays a bit cool. Even after a good, hard run, I couldn't get voltages up much above 0.1V. The GTi sensor had also seen a fair bit of action - the car it came out of had done almost 300,000km. . . .
With the injection setup the RS-X has, I don't think I will get a rich/lean cycle. . .as I said in my first post, the '87 Alto's don't run an oxygen sensor as standard, so I assume mixtures are always set off the base maps in the ECU. . .I would expect this to lead to a steady (maybe 0.5-ish volts?) at idle.
Thanks for your help.
Pete in Perth