X300 Oxygen sensor problem
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X300 Oxygen sensor problem
Hello,
I have a problem with my x300 xjr 1996 aj16. When i read (with a scantool) the voltage from the A oxygen sensors(before the catalyst) i notice that it will be stand all the time at 1,25 volt at idle and when i push the accelator it goes to 0,1 volt for 1 second and goes directly back to 1,25 volt. When i hold the car at 2000 a 3000 rpm the voltage stays at 1,24 - 1,25 volt.
The color of the spark plugs is black.
I recently put 6 new spark plugs in the engine and also 2 new oxygen sensors(before catalyst)
what can cause the problem?
I have a problem with my x300 xjr 1996 aj16. When i read (with a scantool) the voltage from the A oxygen sensors(before the catalyst) i notice that it will be stand all the time at 1,25 volt at idle and when i push the accelator it goes to 0,1 volt for 1 second and goes directly back to 1,25 volt. When i hold the car at 2000 a 3000 rpm the voltage stays at 1,24 - 1,25 volt.
The color of the spark plugs is black.
I recently put 6 new spark plugs in the engine and also 2 new oxygen sensors(before catalyst)
what can cause the problem?
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From: atlanta ga
I really don't want to get in ANOTHER big hairy discussion on this, but I am PRETTY SURE(written description, personal test, etc) that on the Jaguar X300, US spec cars, the rear lamdas do the control. So, IF a rear sensor was bad, you could very well get your results. To diagnose, I sure as heck would chart the response of 4 sensors for variable load and mixture. Move rich, (propane in air inlet), move lean (let air in vacuum hose) and watch response. If you find it hard to believe that the rears do the work on the XJ6, then answer why the european cars have only two sensors, at the after cat location.
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X300 oxygen sensor
Hello, my jaguar x300 is a US spec car.
What is the difference between upstream and downstream oxygen sensors?
Which oxygen sensor (upstream or downstream) doesn't affect the ECM?
Steffen
What is the difference between upstream and downstream oxygen sensors?
Which oxygen sensor (upstream or downstream) doesn't affect the ECM?
Steffen
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From: atlanta ga
steffen:
They both "affect" the ECm, but apparently on an XJ6, the downstreams are the primary control sensors, and the upstream check. That said, there are forum reports that changing the upstream sensors fixed some symptom.... however you will hear most anything.
They both "affect" the ECm, but apparently on an XJ6, the downstreams are the primary control sensors, and the upstream check. That said, there are forum reports that changing the upstream sensors fixed some symptom.... however you will hear most anything.
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When i drive the jaguar for 15 min, and i measure the exhaust gasses, i notice that when the engine idles the λ (lambda value) is 1,075 and CO 0,056 and the A oxygen sensors have both 0,1 volt and when i put the accelerator to 1500 rpm and more the λ (lambda value) goes to 0,950 and the CO to 2 and A oxygen sensors value have both stays at1,250 volt) also when i give more gas (3000-4000rpm)
what can cause that problem?
what can cause that problem?
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OK, so what you have is a slightly lean burn transitioning to rich as you increase revs. Your lambda sensor, CO measurement and sensors all apparently agree. That would INDICATE (not prove) the sensors are fine. You did not comment on how much the sensors transition low to high, so I assume they are "stuck " low at idle and high at speed.
Does your scanner tell you if the engine is in closed loop? I suspect the MAF sensor. There is plenty of archived info on cleaning it. Use MAF sensor cleaner and be careful to only hit the wire with the spray, not the nozzle. Sometimes cleaning works, and reportedly, some times it does not.
Does your scanner tell you if the engine is in closed loop? I suspect the MAF sensor. There is plenty of archived info on cleaning it. Use MAF sensor cleaner and be careful to only hit the wire with the spray, not the nozzle. Sometimes cleaning works, and reportedly, some times it does not.
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hello sparkenzap, i noticed with a hot engine (after 20 min good driving) that the car stays in open loop (what doesit means ?) but when i look at the value (scantool) of the air from (the air mass meter) it goes from 0,07g to 0,22g and more when i give more and more gas it changes upwards.
thank you
thank you
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From: atlanta ga
If you are in openloop, that means the ecu has detected a failure on one or more sensors such that it cannot control the fuel mixture. You need to fix that, since at best you are wasting gas, at worst, you can lean the engine nad burn a valve or piston, or foul a catalytic converter.
So, have you got a cel and any new codes?
So, have you got a cel and any new codes?
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I recently found that the oxygen sensor heater element on one of my oxygen sensors wasn't working. How could I tell? Well the fuel system never went to closed loop, always open loop "fault" condition. I looked at the oxygen sensor readings using a scan tool capable of displaying live data and found that both were switching high/low/high with good transition times.
But when the engine was first switched on one sensor had a slow transition time. It seemed that initially the ECU obtains the oxygen sensor reading and if not within limits (whatever they may be) the ECU will thereafter run open loop "fault". I also found the long term fuel trim to be "-10%" and short term always "0%" - i.e. not used.
No fault codes were set, no MIL/CEL lamp on!
I changed the "sluggish" oxygen sensor (which was "new" BTW!) for another "new" one and, at last, I got closed loop driving.
I also changed the air filter and reconditioned the MAF (cleaned the sensor) which both helped in the emissions testing for the MOT (UK).
But when the engine was first switched on one sensor had a slow transition time. It seemed that initially the ECU obtains the oxygen sensor reading and if not within limits (whatever they may be) the ECU will thereafter run open loop "fault". I also found the long term fuel trim to be "-10%" and short term always "0%" - i.e. not used.
No fault codes were set, no MIL/CEL lamp on!
I changed the "sluggish" oxygen sensor (which was "new" BTW!) for another "new" one and, at last, I got closed loop driving.
I also changed the air filter and reconditioned the MAF (cleaned the sensor) which both helped in the emissions testing for the MOT (UK).
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Hello,
I forgot to say that i disconnected the EGR valve connector at the egr valve and also disconnected the egr sensor connector at the inlet. and i didn't have a check engine light, it goes directly out after engine start (which is normal)
Steffen
I forgot to say that i disconnected the EGR valve connector at the egr valve and also disconnected the egr sensor connector at the inlet. and i didn't have a check engine light, it goes directly out after engine start (which is normal)
Steffen
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