Oxygen senor wired right? Also service manuals
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Joined: Sep 2007
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From: The ******* of Texas
Car: '89 Firebird Formula
Engine: TBI 305
Transmission: T5
Axle/Gears: 10-bolt, 3.42s, Torsen diff.
Oxygen senor wired right? Also service manuals
I got a '92 RS with a TBI 305 a couple of weeks ago for really cheap, and have been correcting the mistakes that the previous owners have made since.
One thing in particular is the O2 sensor wiring. There are 2 wires going down to the one wire sensor, a green and a brown if memory serves correctly. Only the green is connected though. I brought out the DVOM and checked them for voltage when the key was on, and the wire that is connected to the sensor has 12+ volts; the other was showing about .3 volts.
Is this right? FOr what it's worth, I got a Bosch universal 3 wire sensor as per the advice on this board, but I jsut need to get the car running right now.
Lastly, I wouldn't have even asked here if I had a decent service manual. I have a Haynes manual, but they damn near completely ignore the TBI engines. No wiring schematics to amount to a hill of beans. I asked the dealer if they could order a GM factory manual for me, but they said that it wasn't available anymore.
What manual do you guys recommend/use.
One thing in particular is the O2 sensor wiring. There are 2 wires going down to the one wire sensor, a green and a brown if memory serves correctly. Only the green is connected though. I brought out the DVOM and checked them for voltage when the key was on, and the wire that is connected to the sensor has 12+ volts; the other was showing about .3 volts.
Is this right? FOr what it's worth, I got a Bosch universal 3 wire sensor as per the advice on this board, but I jsut need to get the car running right now.
Lastly, I wouldn't have even asked here if I had a decent service manual. I have a Haynes manual, but they damn near completely ignore the TBI engines. No wiring schematics to amount to a hill of beans. I asked the dealer if they could order a GM factory manual for me, but they said that it wasn't available anymore.
What manual do you guys recommend/use.
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Car: 75 Beast
Engine: 383 +EBL Flash
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Re: Oxygen senor wired right? Also service manuals
dit69
What you have is a heated NBO. One of the wires supplies +12 to heater and the other wire is O2 sensor output. Usually, purple wire is used to connect O2 output to the ECM - I do not know what color is used for heater. Ground return is through exhaust manifold.
A three wire BOSCH NBO will have two white wires and one black. The two white wires are used to supply 12 volts to heater element - heater does not care about polarity. Black wire should be connected to O2 ECM input wire (purple). General comments from many TGO members indicate that BOSCH NBO do not work as well as Delco. If you really want to improve NBO operation switch to a four wire AFS-75. This NBO also provides a fourth wire - ground return reference for O2 output all the way to ECM I/O.
With key on, engine off ECM will put DC bias voltage 0.45 volts on O2 sense line. 0.3 volts is a bit low, but it could be due to the ground reference - my case and point for going to a four wire NBO.
When ever possible get factory manual - check out evil bay. For basics Haynes may be adequate.
//RF
What you have is a heated NBO. One of the wires supplies +12 to heater and the other wire is O2 sensor output. Usually, purple wire is used to connect O2 output to the ECM - I do not know what color is used for heater. Ground return is through exhaust manifold.
A three wire BOSCH NBO will have two white wires and one black. The two white wires are used to supply 12 volts to heater element - heater does not care about polarity. Black wire should be connected to O2 ECM input wire (purple). General comments from many TGO members indicate that BOSCH NBO do not work as well as Delco. If you really want to improve NBO operation switch to a four wire AFS-75. This NBO also provides a fourth wire - ground return reference for O2 output all the way to ECM I/O.
With key on, engine off ECM will put DC bias voltage 0.45 volts on O2 sense line. 0.3 volts is a bit low, but it could be due to the ground reference - my case and point for going to a four wire NBO.
When ever possible get factory manual - check out evil bay. For basics Haynes may be adequate.
//RF
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