Black cloud on exhaust at full boost...
#18
“My O2 sensor is broken the signal is beetween 45 and 50 mV instead of arround 500 mV...
But the motronic give 450 mV on the wire which go to the O2 sensor (that explain why i was thinking my O2 sensor was good), is this normal or is it the reson of the O2 sensor breakdown ?”
Having an on/off switch on my O2 sensor, I have made the same observation and believe that the explanation is, that the DME sends out a high impedance ~500mV signal, so it does not correct the fuel supply, if the line to the O2 sensor is broken or the sensor presents an open circuit. If the well-functioning O2 sensor has a much lower impedance (than the ~500 mV from the DME) then its signal will override the “safety signal” from the DME.
Laust
But the motronic give 450 mV on the wire which go to the O2 sensor (that explain why i was thinking my O2 sensor was good), is this normal or is it the reson of the O2 sensor breakdown ?”
Having an on/off switch on my O2 sensor, I have made the same observation and believe that the explanation is, that the DME sends out a high impedance ~500mV signal, so it does not correct the fuel supply, if the line to the O2 sensor is broken or the sensor presents an open circuit. If the well-functioning O2 sensor has a much lower impedance (than the ~500 mV from the DME) then its signal will override the “safety signal” from the DME.
Laust
#19
I thought this was somewhat normal. My 86 did it, and my 88 S did it with Autothority chips and now with Guru chips. Mine does it when I first go full throttle, but that's it. I can look back and see a big cloud from when I first floor it, but it doesn't continue to smoke.
#21
Originally Posted by Laust Pedersen
“My O2 sensor is broken the signal is beetween 45 and 50 mV instead of arround 500 mV...
But the motronic give 450 mV on the wire which go to the O2 sensor (that explain why i was thinking my O2 sensor was good), is this normal or is it the reson of the O2 sensor breakdown ?”
Having an on/off switch on my O2 sensor, I have made the same observation and believe that the explanation is, that the DME sends out a high impedance ~500mV signal, so it does not correct the fuel supply, if the line to the O2 sensor is broken or the sensor presents an open circuit. If the well-functioning O2 sensor has a much lower impedance (than the ~500 mV from the DME) then its signal will override the “safety signal” from the DME.
Laust
But the motronic give 450 mV on the wire which go to the O2 sensor (that explain why i was thinking my O2 sensor was good), is this normal or is it the reson of the O2 sensor breakdown ?”
Having an on/off switch on my O2 sensor, I have made the same observation and believe that the explanation is, that the DME sends out a high impedance ~500mV signal, so it does not correct the fuel supply, if the line to the O2 sensor is broken or the sensor presents an open circuit. If the well-functioning O2 sensor has a much lower impedance (than the ~500 mV from the DME) then its signal will override the “safety signal” from the DME.
Laust
But my o2 sensor has a wrong signal but is heating correctly...
And when the o2 sensor is disconnected, i've the same black clouds
thanks
#22
I have a 3bar FPR and my car smokes under hard acceleration. I always attributed it to the FPR.
I am currently installing IceSharks headlight kit and upon disassembly I noticed that the vaccum line that connects to the bottom of the throttle body was not connected. I wonder if that could be part of my problem.
Anyone have a 3 BAR FPR with the same problem.
Come to think of it my car leaves a little black stain on my driveway if I let it idle for awhile.
I am currently installing IceSharks headlight kit and upon disassembly I noticed that the vaccum line that connects to the bottom of the throttle body was not connected. I wonder if that could be part of my problem.
Anyone have a 3 BAR FPR with the same problem.
Come to think of it my car leaves a little black stain on my driveway if I let it idle for awhile.
#23
I've tried another time without o2 sensor, and there no smoke, someone was behind me to see it.
So it's a good news, i will by the sensor and i tell you if it's was really the problem ;-)
So it's a good news, i will by the sensor and i tell you if it's was really the problem ;-)
#24
Alex, my car does the same thing! I have a 89 944 Turbo. It will make some smoke, as it is programmed to run a little rich. There is not a lot of smoke at all, but some appears when I am under full boost. It seems to make more smoke when I run 100 octane fuel. I have a larger turbo too, so it needs more fuel!