horrible fuel economy.
#102
Removing the connector on the 2 wire ECT sensor how many ohms resistance do you read ?
It can be compared to a chart on page 78 of the Jaguar 801s PDF
Your gauge reading of 91 C should be around 250 ohms
The thermostat is set for just above the 88 C and not the blue marking on the gauge, so I see no coolant temp or flow issue
Looks like a hot beverage thermometer
It can be compared to a chart on page 78 of the Jaguar 801s PDF
Your gauge reading of 91 C should be around 250 ohms
The thermostat is set for just above the 88 C and not the blue marking on the gauge, so I see no coolant temp or flow issue
Looks like a hot beverage thermometer
Last edited by Parker 7; 10-01-2022 at 12:36 AM.
#103
Removing the connector on the 2 wire ECT sensor how many ohms resistance do you read ?
It can be compared to a chart on page 78 of the Jaguar 801s PDF
Your gauge reading of 91 C should be around 250 ohms
The thermostat is set for just above the 88 C and not the blue marking on the gauge, so I see no coolant temp or flow issue
Looks like a hot beverage thermometer
It can be compared to a chart on page 78 of the Jaguar 801s PDF
Your gauge reading of 91 C should be around 250 ohms
The thermostat is set for just above the 88 C and not the blue marking on the gauge, so I see no coolant temp or flow issue
Looks like a hot beverage thermometer
i have to put it onto continuity setting. I assume that is 20 ohm setting and i was getting a reading of 280
and yes that is a hot beverage thermometer. Though it would be accurate enough to give a good idea.
#105
#106
The air temperature sensor may have stripped the threads in that plastic elbow. You might want to find a replacement on eBay or something. I’d be worried about vacuum leaks now.
The following items need to be read by the ECU to enter closed loop:
1. TPS
2. MAF
3. Oxygen Sensors
4. Coolant Temp Sensor
If one of those sensors is not providing data within expected ranges, ECU stays in open loop.
You can trick the Coolant Temp Sensor by jumping the two contacts on the harness when you disconnect it.
When was the last time you replaced the oxygen sensors? They do wear out and should be replaced every 60,000 miles.
Driving in open loop does result in terrible fuel economy; so you’re on the right track….
The following items need to be read by the ECU to enter closed loop:
1. TPS
2. MAF
3. Oxygen Sensors
4. Coolant Temp Sensor
If one of those sensors is not providing data within expected ranges, ECU stays in open loop.
You can trick the Coolant Temp Sensor by jumping the two contacts on the harness when you disconnect it.
When was the last time you replaced the oxygen sensors? They do wear out and should be replaced every 60,000 miles.
Driving in open loop does result in terrible fuel economy; so you’re on the right track….
Last edited by Vee; 10-01-2022 at 07:00 AM.
#107
contained in this thread is all the details about the o2 sensors.
i changed them on the 28th August.
it does appear that the temp sensor is reading properly but i will try jumping the contacts to see if it makes any difference.
it appears the TPS is reading correctly as the torque app is showing 10.59 at idle right up to 100% with WOT. and i have confirmed by adjusting throttle cable and visually checking butterfly to confirm it is opening and the reading appears to match how much it is open. it reads 10.59 but the butterfly appears fully closed. i assume this is correct.
i have cleaned the MAF so i think it is working correctly but am not sure how to test/check.
i would like to get a vacuum tester and test for vacuum leaks but i do not have anything to do that with.
the sensor in the elbow appears the plastic part has broken off the metal thread and is spinning but not actually loosening. i have wrapped some silicone tape around it and put a cable tie there also just to ensure it is not leaking even tho i am sure it is not
same thing has now happened to my coolant temp sensor as when i went to remove it the plastic part is turning and turning but the thread is not loosening at all. and i know here that it is still sealed as there is no leaking.
i changed them on the 28th August.
it does appear that the temp sensor is reading properly but i will try jumping the contacts to see if it makes any difference.
it appears the TPS is reading correctly as the torque app is showing 10.59 at idle right up to 100% with WOT. and i have confirmed by adjusting throttle cable and visually checking butterfly to confirm it is opening and the reading appears to match how much it is open. it reads 10.59 but the butterfly appears fully closed. i assume this is correct.
i have cleaned the MAF so i think it is working correctly but am not sure how to test/check.
i would like to get a vacuum tester and test for vacuum leaks but i do not have anything to do that with.
the sensor in the elbow appears the plastic part has broken off the metal thread and is spinning but not actually loosening. i have wrapped some silicone tape around it and put a cable tie there also just to ensure it is not leaking even tho i am sure it is not
same thing has now happened to my coolant temp sensor as when i went to remove it the plastic part is turning and turning but the thread is not loosening at all. and i know here that it is still sealed as there is no leaking.
Last edited by Spud Maat; 10-01-2022 at 07:16 AM.
#108
ok, so i just used a wire to jump the coolant temp sensor plug and it actually made the idle worse. the car was more reluctant to start than i have seen it ever, sort of spluttered a bit and then the idle in park began to climb past 1400.
all this messing around i am doing and i will probably find its a vacuum leak. i can't see or find anything obvious. but who knows.
or it will be the idle air control valve.
all this messing around i am doing and i will probably find its a vacuum leak. i can't see or find anything obvious. but who knows.
or it will be the idle air control valve.
Last edited by Spud Maat; 10-01-2022 at 07:29 AM.
#109
On your ECU connector socket Red 14 and Red 31 you should see the same 280 ohms resistance after you have warmed the engine up
You would have to do the reading quickly after engine shut down and coolant cool down for accuracy
This would be what the ECU sees to get your closed loop mode and verifies a not bad connector sockets and wiring between , there are no wire splices in between the sensor and ECU
By taking a paper clip and 0 resistance for sensor value the ECU may be rejecting the sensor value and go into a limp mode
Send a pic to verify correct meter switch selection to be sure
Your 280 value is right on the edge of the 88 C for closed loop, but the accuracy error and meter calibration of the reading may be a factor
2 / 100 ohm resistors in series at the ECT sensor connector will be in an expected range and you may see on your device closed loop
You might be at a thermostat part change and is important that no O - ring on installation as parts from the vendors get mixed around
The X300 uses no O - ring because it cracks the thermostat housing casting as you clamp it down
You would have to do the reading quickly after engine shut down and coolant cool down for accuracy
This would be what the ECU sees to get your closed loop mode and verifies a not bad connector sockets and wiring between , there are no wire splices in between the sensor and ECU
By taking a paper clip and 0 resistance for sensor value the ECU may be rejecting the sensor value and go into a limp mode
Send a pic to verify correct meter switch selection to be sure
Your 280 value is right on the edge of the 88 C for closed loop, but the accuracy error and meter calibration of the reading may be a factor
2 / 100 ohm resistors in series at the ECT sensor connector will be in an expected range and you may see on your device closed loop
You might be at a thermostat part change and is important that no O - ring on installation as parts from the vendors get mixed around
The X300 uses no O - ring because it cracks the thermostat housing casting as you clamp it down
Last edited by Parker 7; 10-01-2022 at 02:58 PM.
#110
#111
The reading i was getting at 280 was a little while after the car was running so it would have cooled down a little.
i tested again a little later and it was reading 300.
so the sensor does appear to work
after next drive i will test immediately to see where it is at.
i have a spare sensor so what i might do is full a cup with very hot water and see that sensor and see what happens…
is there an easy way to test the operation of the idle air control valve?
i would think it is working atleast to a point as if i disconnect the coolant temp sensor the idle will rise a lot. That indicates to me that it is opening up but maybe it cannot close enough so it cannot change the idle when car is hot
@Parker 7 on the continuity/lowest resistance setting.
200 ohm gives no reading as its too low resistance.
i tested again a little later and it was reading 300.
so the sensor does appear to work
after next drive i will test immediately to see where it is at.
i have a spare sensor so what i might do is full a cup with very hot water and see that sensor and see what happens…
is there an easy way to test the operation of the idle air control valve?
i would think it is working atleast to a point as if i disconnect the coolant temp sensor the idle will rise a lot. That indicates to me that it is opening up but maybe it cannot close enough so it cannot change the idle when car is hot
@Parker 7 on the continuity/lowest resistance setting.
200 ohm gives no reading as its too low resistance.
Last edited by Spud Maat; 10-01-2022 at 06:53 PM.
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Parker 7 (10-01-2022)
#112
300 ohms puts you under the 88 C tipping point for close loop
this doesn't point to the sensor as it does seem to respond
The continuity test position with the diode symbol is not the best meter switch position
try the 2k ohm position
The sensor is a thermistor which is a solid-state device that has to be powered by a 9 volt battery powered meter which yours looks most likely and not a micro sized meter powered by 1.5 volt batteries
The IAC valve motor is hard to test in practice as they most likely fail when the stepper motor is heated and ex[anded as well as tapping on it
this doesn't point to the sensor as it does seem to respond
The continuity test position with the diode symbol is not the best meter switch position
try the 2k ohm position
The sensor is a thermistor which is a solid-state device that has to be powered by a 9 volt battery powered meter which yours looks most likely and not a micro sized meter powered by 1.5 volt batteries
The IAC valve motor is hard to test in practice as they most likely fail when the stepper motor is heated and ex[anded as well as tapping on it
Last edited by Parker 7; 10-01-2022 at 07:33 PM.
#113
i will try it on the 2k setting. i just figured if it got no reading on the 200 then going to continuity was btte than the 2k setting.
i will be headed to my car soon and will test my spare sensor using hot (almost boiling) water and see what reaction i get.
to determine if maybe the sensor is reading correct but the car is not reaction to the reading
i will be headed to my car soon and will test my spare sensor using hot (almost boiling) water and see what reaction i get.
to determine if maybe the sensor is reading correct but the car is not reaction to the reading
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Parker 7 (10-01-2022)
#114
Your readings are too close to either side of the 88 C tiping point
This points to a new thermostat if no faults found in the wiring condition and timely / accuracy reading precautions
Did you get a EML 327 device ECT temperature that corresponds to your meter resistance readings ?
This points to a new thermostat if no faults found in the wiring condition and timely / accuracy reading precautions
Did you get a EML 327 device ECT temperature that corresponds to your meter resistance readings ?
Last edited by Parker 7; 10-01-2022 at 07:49 PM.
#115
#120