98 XJR running rough!
#21
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Hi Everyone,
Today: Checked/charged battery, volts OK.
Removed/dried/cleaned spark plugs and checked for spark, all OK.
Removed cam sensor connector while running... stopped engine, OK.
Removed MAF air connection whilst running... stopped engine, OK.
Again introduced butane gas around possible suspects for air leak... no effect.
All the 8 plugs are wet with fuel when checked.
Is it possible the electronic throttle is faulty?... I'm fast running out of things to eliminate!!
Today: Checked/charged battery, volts OK.
Removed/dried/cleaned spark plugs and checked for spark, all OK.
Removed cam sensor connector while running... stopped engine, OK.
Removed MAF air connection whilst running... stopped engine, OK.
Again introduced butane gas around possible suspects for air leak... no effect.
All the 8 plugs are wet with fuel when checked.
Is it possible the electronic throttle is faulty?... I'm fast running out of things to eliminate!!
#22
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Wet plugs indicate low/weak spark.
Try fresh spark plugs?
Also, unplug the o2 sensors and see if there is any difference in running.
Shouldn't the car run in default mode witth eh MAF unplugged though?
The brain is going add or delete fuel based on the reading from the MAF and O2 sensors, so... if it is overfueling those would be logical points to check- unless the plugs are wack.
Do you have a scan tool that will let you take real time readings? This will allow you to see things like throttle position and O@ readings/trim to see if they are giving bad readings.
Try fresh spark plugs?
Also, unplug the o2 sensors and see if there is any difference in running.
Shouldn't the car run in default mode witth eh MAF unplugged though?
The brain is going add or delete fuel based on the reading from the MAF and O2 sensors, so... if it is overfueling those would be logical points to check- unless the plugs are wack.
Do you have a scan tool that will let you take real time readings? This will allow you to see things like throttle position and O@ readings/trim to see if they are giving bad readings.
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warrickUK (10-07-2012)
#23
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Hi, many thanks for that.
The plugs are new but the old ones were working OK, so I could swap them back. I'll get on to checking the o2 sensors in the morning.
My scanner will record real time data though I'm inexperienced with it and I'm not sure what to be looking for however I'll come back here with what I can find re throttle etc!
Cheers!
The plugs are new but the old ones were working OK, so I could swap them back. I'll get on to checking the o2 sensors in the morning.
My scanner will record real time data though I'm inexperienced with it and I'm not sure what to be looking for however I'll come back here with what I can find re throttle etc!
Cheers!
#24
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You might also want to check the actual throttle cable in case it is too tight.
There is also a static resistance test for the TPS potentiometers. The values and procedure may be in JTIS.
BTW, useless post and response to useless post deleted.
Last edited by plums; 10-07-2012 at 04:03 PM.
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warrickUK (10-08-2012)
#25
#28
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warrickUK (10-09-2012)
#29
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Hi All,
Today: Hard re-setted, Still will not run, still throwing vast amounts of fuel into the engine and gueing up plugs.
Disconnected both o2 sensors, no different.
I have again checked cam timing ... still OK!
Checked spark... it's excellent, then swapped for a different set of spark plugs, no different, will not run beyond 10 seconds. Any movement on throttle stops the engine.
Had local mobile Diagnostic Tech. guy to help analyse my problem with his 'Snap On' scanning gear, he also can't find any faults.
What's my next step please???
This really is becoming an epic and unfortunately there is no Jaguar help locally, I'm relying on you guys to help me through this...!
Today: Hard re-setted, Still will not run, still throwing vast amounts of fuel into the engine and gueing up plugs.
Disconnected both o2 sensors, no different.
I have again checked cam timing ... still OK!
Checked spark... it's excellent, then swapped for a different set of spark plugs, no different, will not run beyond 10 seconds. Any movement on throttle stops the engine.
Had local mobile Diagnostic Tech. guy to help analyse my problem with his 'Snap On' scanning gear, he also can't find any faults.
What's my next step please???
This really is becoming an epic and unfortunately there is no Jaguar help locally, I'm relying on you guys to help me through this...!
#31
#32
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I just checked mine and it does whirr continually until I start the car.
Sounds like you have a problem in the throttle body- hopefully it will be an easy fix now that we found the culprit.
Try uplugging and replugging your throttle body connector.
Here are my readings for what it is worth, at idle:
STFT B1: -2.3 B2: -3.9
LTFT B1:1.5 B2: 6.2
RPP: 665
TPS: 1.5% <<I think this is where your problem lies.
Sounds like you have a problem in the throttle body- hopefully it will be an easy fix now that we found the culprit.
Try uplugging and replugging your throttle body connector.
Here are my readings for what it is worth, at idle:
STFT B1: -2.3 B2: -3.9
LTFT B1:1.5 B2: 6.2
RPP: 665
TPS: 1.5% <<I think this is where your problem lies.
Last edited by dsnyder586; 10-09-2012 at 04:43 PM.
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warrickUK (10-10-2012)
#33
#34
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OK, just checked TP % and it's 5.5% at idle and now working through the range OK... damn, thought we had it!
The other symptom was the erratic on/off of the cooling fans and I notice the rev counter stops and starts and dash lights flicker just before the engine cuts. I'll try connecting an earth wire from the head to the body and direct to the battery. Let you know what happens.
The other symptom was the erratic on/off of the cooling fans and I notice the rev counter stops and starts and dash lights flicker just before the engine cuts. I'll try connecting an earth wire from the head to the body and direct to the battery. Let you know what happens.
#36
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The TP % at idle position shows 5.5% and will increase gradually with pedal movement through to 79%.
Fixing earth wires to the engine made no difference.
Mobile Tech. guy returned today with a more 'Jaguar specific' scanner programme, momentarily showed a crank sensor fault but that cleared and afterwards showed 'no faults'. Is it worth trying a new crank sensor now?
Fixing earth wires to the engine made no difference.
Mobile Tech. guy returned today with a more 'Jaguar specific' scanner programme, momentarily showed a crank sensor fault but that cleared and afterwards showed 'no faults'. Is it worth trying a new crank sensor now?
#37
#38
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I've removed the sensor on a couple of occasions when fitting the locking tool for cam shaft setting, it looked perfectly OK then.
What on the flywheel does the sensor detect to give it a signal? could I have damaged something when I jammed the flywheel in order to loosen the crankshaft pulley bolt??
Thanks.
What on the flywheel does the sensor detect to give it a signal? could I have damaged something when I jammed the flywheel in order to loosen the crankshaft pulley bolt??
Thanks.
#39
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hmmm, might be onto something here, I was cautioned about doing the same thing, by loosening the crank pulley bolt and relying on the dummy sensor can damage the starter ring gear.
I don't know the symptoms - but timing out and overfuel, it's possible.
There's a Jaguar special tool that holds the pulley as you undo the nut...
The other pic is of the starter ring and the slot with curved top and bottom is the where the locking tool slots. This might be worth checking out...
I don't know the symptoms - but timing out and overfuel, it's possible.
There's a Jaguar special tool that holds the pulley as you undo the nut...
The other pic is of the starter ring and the slot with curved top and bottom is the where the locking tool slots. This might be worth checking out...
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warrickUK (10-10-2012)
#40