tadek
04-07-2005, 09:51 PM
What should be a range of voltage from mass air sensor
for BMW 525i year 92. May be somebody can measure it ( Please !!! )
In my car it is ~2.4 V for idle and it goes up to about 2.8V for 2500rpm
I doubt if the range is OK however tendency is OK. I understand that depends
also on temperature, but the voltage delta = ~0.4V is too small or rather I will say I think it is too small( ???). Bentley manual is inacurate and states voltage should be withn the range 0 - 5 V ???????.
Car behaves like that:
When it is cold and engine is started on, everything is OK - I am not really shure if everything
is OK but there in no light Check Engine. After 20 min of running engine or more( Check Engine is not active )
and turning it off, let engine cool down for 10 minutes and starting engine once again. Check Engine light is ON after ~30 seconds and remains active all the time.
Code from computer says error 46 - oxygen sensor. First time that sensor has been changed at professional service ( car was OK for 1 week ). within last year I changed that sensor already 4 times, computer has been changed too, I did check all the basics around ( I have checked fuel pressure it is OK.) At temp. 68 F inlet air and coolant temperature sensors resistance is ~2.3 kOhm, third sensor located next to coolant sensor has a resistance 6.7 kOhm ( I don't know
its designation ).Throttle potentiometer is OK Spark plugs color shows that is a too much fuel in the mixture and all 6 of them looks the same way( of course I have
changed them many times ) Each changed oxygen sensor is quicky covered with a black layer of that what engine didn't burned out properly.
Oxygen sensor relay is OK, I can monitor voltage and current which flows to oxygen sensore so I am sure it is OK
What next I should put on the check list?? Fuel injectors ?? I can take them out, check coil resistance, but it is not a real test.
Thanks in advance for remarks
Tadek
for BMW 525i year 92. May be somebody can measure it ( Please !!! )
In my car it is ~2.4 V for idle and it goes up to about 2.8V for 2500rpm
I doubt if the range is OK however tendency is OK. I understand that depends
also on temperature, but the voltage delta = ~0.4V is too small or rather I will say I think it is too small( ???). Bentley manual is inacurate and states voltage should be withn the range 0 - 5 V ???????.
Car behaves like that:
When it is cold and engine is started on, everything is OK - I am not really shure if everything
is OK but there in no light Check Engine. After 20 min of running engine or more( Check Engine is not active )
and turning it off, let engine cool down for 10 minutes and starting engine once again. Check Engine light is ON after ~30 seconds and remains active all the time.
Code from computer says error 46 - oxygen sensor. First time that sensor has been changed at professional service ( car was OK for 1 week ). within last year I changed that sensor already 4 times, computer has been changed too, I did check all the basics around ( I have checked fuel pressure it is OK.) At temp. 68 F inlet air and coolant temperature sensors resistance is ~2.3 kOhm, third sensor located next to coolant sensor has a resistance 6.7 kOhm ( I don't know
its designation ).Throttle potentiometer is OK Spark plugs color shows that is a too much fuel in the mixture and all 6 of them looks the same way( of course I have
changed them many times ) Each changed oxygen sensor is quicky covered with a black layer of that what engine didn't burned out properly.
Oxygen sensor relay is OK, I can monitor voltage and current which flows to oxygen sensore so I am sure it is OK
What next I should put on the check list?? Fuel injectors ?? I can take them out, check coil resistance, but it is not a real test.
Thanks in advance for remarks
Tadek
