1989 bonneville 3.8 ln3 stays on open loop
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many vehicles in the past have failed emissions because, they drove their vehicle to the inspection station, and then either turned their vehicle off or just let it idle while waiting for the inspection....many times, especially if an old O2 sensor was in the vehicle(they become "lazy" as they age), that sensor would not get hot enough to start to work.
SoooOOooOOoo glad I don't have to put up with that any more.
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Here is an old trick:
Disconnect the single wire O2 sensor.......turn key to on, don't start.....observe O2 voltage....should be around 0.455 volts in data.... now take a wire and attach it the harness half going to the ECM, not the half going to the O2 sensor....
Now hold the other end of the wire with one hand, and with the other hand, touch your index finger to the pos bat post.....O2 data should approach 1.0 volt.....now move the index finger to the neg bat terminal and data should approach 0.0 volts....if you get these readings, then the O2 sensor/harness is bad.....
If you don't get these readings, there is a harness problem/ECM problem....
You CAN'T go into closed loop if the O2 sensor is not providing a varying signal....
Disconnect the single wire O2 sensor.......turn key to on, don't start.....observe O2 voltage....should be around 0.455 volts in data.... now take a wire and attach it the harness half going to the ECM, not the half going to the O2 sensor....
Now hold the other end of the wire with one hand, and with the other hand, touch your index finger to the pos bat post.....O2 data should approach 1.0 volt.....now move the index finger to the neg bat terminal and data should approach 0.0 volts....if you get these readings, then the O2 sensor/harness is bad.....
If you don't get these readings, there is a harness problem/ECM problem....
You CAN'T go into closed loop if the O2 sensor is not providing a varying signal....
So example: i but red wire to o2 harnes, ecm side not o2 sensor side.
I take red wire to left hand and touch car battery + with right hand? Or left hand but wire is inside my hand and not touching straight to + and getting 12v? Straight 12v in red wire blows ecm?
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And if o2 is not only which can lock open loop, example maf is other reason?
If open loop is locked will it show o2 volts in ecm even wiring and ecm is good and i do the wire test?
Some forums said that o2, maf and engine temp sensor can lock open loop if some of those are broken
If open loop is locked will it show o2 volts in ecm even wiring and ecm is good and i do the wire test?
Some forums said that o2, maf and engine temp sensor can lock open loop if some of those are broken
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No, do not connect the wire directly to the bat post!!!!!!!!!!!!
Your body acts like a big resistor!!!!!!
Hold the bare end of the wire with one hand, and with the index finger of your other hand, touch the pos term and look for a change in O2 data near 1.0 volts, and then put you index finger on the neg term, and look for a change in data to near zero.......with nothing connected, should get a reading of .455 volts.....
Can do this with engine "on"(not running)........
Your body acts like a big resistor!!!!!!
Hold the bare end of the wire with one hand, and with the index finger of your other hand, touch the pos term and look for a change in O2 data near 1.0 volts, and then put you index finger on the neg term, and look for a change in data to near zero.......with nothing connected, should get a reading of .455 volts.....
Can do this with engine "on"(not running)........
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No, do not connect the wire directly to the bat post!!!!!!!!!!!!
Your body acts like a big resistor!!!!!!
Hold the bare end of the wire with one hand, and with the index finger of your other hand, touch the pos term and look for a change in O2 data near 1.0 volts, and then put you index finger on the neg term, and look for a change in data to near zero.......with nothing connected, should get a reading of .455 volts.....
Can do this with engine "on"(not running)........
Your body acts like a big resistor!!!!!!
Hold the bare end of the wire with one hand, and with the index finger of your other hand, touch the pos term and look for a change in O2 data near 1.0 volts, and then put you index finger on the neg term, and look for a change in data to near zero.......with nothing connected, should get a reading of .455 volts.....
Can do this with engine "on"(not running)........
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I tried that engine running. Without o2 plugged mv varies 200-600mv. Wire on ecm o2 wire and my hand, touching negative = nothing change. Touching positive = 1000mv.
So there is live in ecm and wire?
So there is live in ecm and wire?
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"running it with the A+B jumpered puts it in "field service mode". If it'* in open loop it the CEL will flash 2.5 times a sec and 1 times a sec for closed loop."
Will this trick work on my car or only tbi vehicles?
Will this trick work on my car or only tbi vehicles?
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Car works in closed loop now. New o2 and exhaust cleaning where o2 came cured problem.
But..
Before it cutted on 3500-4000rpm in full throttle, now only sometimes in 5000rpm. So its better now.
Will o2 sensor adjust full throttle fueling by itself or is there something sensors like maf which adjust it too?
Is my new o2 sensor too slow in full throttle and cant rich fuel that fast?
But..
Before it cutted on 3500-4000rpm in full throttle, now only sometimes in 5000rpm. So its better now.
Will o2 sensor adjust full throttle fueling by itself or is there something sensors like maf which adjust it too?
Is my new o2 sensor too slow in full throttle and cant rich fuel that fast?
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Okay, but only in wot? How about if i raise throttle more genty up to 4000-5000rpm? Not smashing pedal to floor quick.
Something cured this problem higher rpm than before and o2 was only what i replaced.
thre is link to acceleration video
https://aijaa.com/a1VqXo
It sounds like wrc rally car when it sputters.
Fuel pressure ,pump, filter ok and injectors tested good.
Something cured this problem higher rpm than before and o2 was only what i replaced.
thre is link to acceleration video
https://aijaa.com/a1VqXo
It sounds like wrc rally car when it sputters.
Fuel pressure ,pump, filter ok and injectors tested good.
