1995 XJR non start - buy scanner?
Discussion
I'm just about tearing my hair out because my car won't start. I've fuel and spark and the battery turns the engine over nicely, but, still no start. I'm beginning to think about buying a diagnostic scanner which should assist me although I've never used one before. Does anyone use such a device? I believe the car runs on OBD2 (OBDII)
How do you know you have fuel and spark??
Sorry if that sounds stupid, but If you did it would start.
Commons things for non start on 300's, fuel pump and crank sensor, so that why I'm a bit dubious that you got both.
So tell me how you tested it and I'll see if I can tell you how to get it going.
Non start basics.
Do you have a Good spark on all 6 coils, (coils are common fault also, but normally misfires rather than all 6 go down and fail to start).
Do you have fuel pressure, (without a pressure gauge you can test be opening the 17mm/19mm union to the fuel rail and it should gush out)
Do you have injector pulse. Hard to test without the correct equipment, but if you take the plugs out and spin it over you will see, smell the fuel coming out. Disconnect the coils completely for this bit, if there nearby they will ignite the vapour.
Do you have compression?
Sorry if that sounds stupid, but If you did it would start.
Commons things for non start on 300's, fuel pump and crank sensor, so that why I'm a bit dubious that you got both.
So tell me how you tested it and I'll see if I can tell you how to get it going.
Non start basics.
Do you have a Good spark on all 6 coils, (coils are common fault also, but normally misfires rather than all 6 go down and fail to start).
Do you have fuel pressure, (without a pressure gauge you can test be opening the 17mm/19mm union to the fuel rail and it should gush out)
Do you have injector pulse. Hard to test without the correct equipment, but if you take the plugs out and spin it over you will see, smell the fuel coming out. Disconnect the coils completely for this bit, if there nearby they will ignite the vapour.
Do you have compression?
Thanks for the replys, chaps. Well, it was a pretty basic test for spark and fuel. I cranked while the sparkplug was in the coil and earthed onto a bolt on the engine. Fuel? Well the sparkplug was wet and smelt of fuel. Fuel pressure? I don't know if I've got that. There also needs to be air for combustion to take place. I believe if the throttle position sensor (which I didn't know the car had until recently) is goosed, again, the car might not fire. I've decided to invest in the Autoenginuity's OBD2 Scan Tool as this car is a keeper and if it works (or rather - if I can work it) it should save me money in the longer term. It works on (X300) Jaguars from 1995 to present. Anyone used one?
Sounds like its over fueling from your describtion.
Whip the inlet trunking off and make sure the throttle isnt jammed shut.
Fauly throttle pot can cause overfueling but usually just makes if run rough rather than not start at all.
Have seen a couple of XJR's in the past where an electrical fault caused the injectors to squirt continuously not pulse like they are supposed to, but cant remember what caused if for the life of me.
Advise dry the plugs preferable with a hot air gun or fag lighter, somthing that will burn off teh fuel and heat then up, then retry to start teh car as if its flooded. "full throtle while cranking" A small amount of oil down each plug hole wont hert, but thats more of a V8 trick than for the XJ16.
Once running see if you can tell if its just missing one cylinder or all 6 are playing up.
Was the throttle pot the only fault stored??
Whip the inlet trunking off and make sure the throttle isnt jammed shut.
Fauly throttle pot can cause overfueling but usually just makes if run rough rather than not start at all.
Have seen a couple of XJR's in the past where an electrical fault caused the injectors to squirt continuously not pulse like they are supposed to, but cant remember what caused if for the life of me.
Advise dry the plugs preferable with a hot air gun or fag lighter, somthing that will burn off teh fuel and heat then up, then retry to start teh car as if its flooded. "full throtle while cranking" A small amount of oil down each plug hole wont hert, but thats more of a V8 trick than for the XJ16.
Once running see if you can tell if its just missing one cylinder or all 6 are playing up.
Was the throttle pot the only fault stored??
Straight6DOHC said:
I've decided to invest in the Autoenginuity's OBD2 Scan Tool as this car is a keeper and if it works (or rather - if I can work it) it should save me money in the longer term. It works on (X300) Jaguars from 1995 to present. Anyone used one?
I bought one of these tools lat year, absolutely invaluable....it's not a 'fix it' tool, but rather it gives you the code and a brief description of fault, so makes a good starting point for rectification. I would also recommend the JTIS cd for 'a manual' unless you have one otherwise?Good luck
Tame Technician, I called the technical advisor at the JEC and he told me there could be a stuck trottle - apparently a faily commom problem on the XJR6 and the throttle body needs to come off to clean it. Getting the throttle body off is a very big job and one which might be easier done from under the car. I have access to a lift but can't get the car on it as it isn't running. I have the air trunking off the car already - is it possible to see the throttle (and it opening and closing) with the trunking off on the XJR6? The plugs didn't actually look too bad. They are only 2000-3000 miles old (1 year) and although a little sooty (cracked manifolds causing this?) have cleaned up fine - they have been drying indoors for days now. The technical advisor felt that on this car it was best to get a diagnosis performed, I emailed a local mobile service but when I told them the car and the events leading up to it (sat for a month then didn't start) they didn't get back in touch. I figured it would cost me £100 (ball park figure) for them to give me a diagnosis so that's what led me to buy a scanning tool - it'll be in the post as we speak.
Sparky35uk, I'm glad you feel the scanner fits the bill. How do you feel it is to use? I don't think I'm particularly adept with computers and home mechanics is either self taught or knowledge passed on from my father (mostly self taught), reading books and forums such as this. It's a bit of unknown territory for me but I hope this tool will help me for years to come.
As ever chaps, all advice is appreciated.
Sparky35uk, I'm glad you feel the scanner fits the bill. How do you feel it is to use? I don't think I'm particularly adept with computers and home mechanics is either self taught or knowledge passed on from my father (mostly self taught), reading books and forums such as this. It's a bit of unknown territory for me but I hope this tool will help me for years to come.
As ever chaps, all advice is appreciated.
They are very easy to use (or least mine is!), it just plugs into the socket, which looks like a scart socket, located in the drivers footwell, near the centre console - or at least it is on the XJ8, so yours should be the same I would have thought.
Just follow the instructions on the screen and it will give you the codes (if any) and it should also give you the chance to re-set and clear the codes afterwards.
Just follow the instructions on the screen and it will give you the codes (if any) and it should also give you the chance to re-set and clear the codes afterwards.
So sorry I forgot the XJR is different, charge cooler in the way isnt it, I was thinking of the normal XJ6's where you can just look inside realy easy. Its really hard to see on the XJR6, you should be able to with a dentist mirror on a stick and torch, from under the car, get someone to open and close the throtle while you have a look, but to be honest if it was stuck shut I think you would feel the resistance on the pedal/cable etc.
Cracked Ex. manifolds have nothing to do with how the engine fuels so wont have anything to do with it no. They can be welded up and hidden under the heat shield rather than replaced, (very expensive items)
I've never used that scan tool but there all much of a muchness, so I wouldnt worry about not being able to use it, I'm sure you will be fine. A code reader or scanner or what ever you want to call it will only display the fault codes stored in the memory, while I strongly feel its an invaluable tool and everone should have one, it wont fix the car!
Part of the skills of diagnostic is interpreting what the car is saying, Often with a non start, there will be a number of sperious codes to ignore that could send you the wrong way. Equally it may have stored nothing as it hasnt run long enough to notice anything wrong.
Have you had the codes read yet, I though you said it had a failed throtle pot "potentiomenter / position sensor".
With non starts, you need to do the basics first, spark, on all 6, not just the one you tested first. ?
Fuel pressure, you only need a 17 and 19 mm spanner to check this, crack the union open and see if it jets out.
Are the injectors firing, Idealing you want to remove the three tork screws that hold the plastic cover of the injectors and check for a pulse with a noid light or multi meter. Each injector should have a 12volt ignition feed and a switched earth.
Alternativly but not as good a test - When you spin it over with all the plugs out can you see a mist of fuel coming out (the injectors are firing)
When its turning over (with all the plugs back in) does it sound like its got compression.
Have you checked all of that, did you find anything.
Cracked Ex. manifolds have nothing to do with how the engine fuels so wont have anything to do with it no. They can be welded up and hidden under the heat shield rather than replaced, (very expensive items)
I've never used that scan tool but there all much of a muchness, so I wouldnt worry about not being able to use it, I'm sure you will be fine. A code reader or scanner or what ever you want to call it will only display the fault codes stored in the memory, while I strongly feel its an invaluable tool and everone should have one, it wont fix the car!
Part of the skills of diagnostic is interpreting what the car is saying, Often with a non start, there will be a number of sperious codes to ignore that could send you the wrong way. Equally it may have stored nothing as it hasnt run long enough to notice anything wrong.
Have you had the codes read yet, I though you said it had a failed throtle pot "potentiomenter / position sensor".
With non starts, you need to do the basics first, spark, on all 6, not just the one you tested first. ?
Fuel pressure, you only need a 17 and 19 mm spanner to check this, crack the union open and see if it jets out.
Are the injectors firing, Idealing you want to remove the three tork screws that hold the plastic cover of the injectors and check for a pulse with a noid light or multi meter. Each injector should have a 12volt ignition feed and a switched earth.
Alternativly but not as good a test - When you spin it over with all the plugs out can you see a mist of fuel coming out (the injectors are firing)
When its turning over (with all the plugs back in) does it sound like its got compression.
Have you checked all of that, did you find anything.
Tame Technician, the stuck throttle was only a suggestion from the JEC...I've not had the car 'read' yet. Hopefully the scanning tool will arrive on monday. However, until then I now know exactly what to do tomorrow. Thanks again, I'll report back with an update on all of the above.
Cheers.
Cheers.
Ok, all 6 plugs and coils are producing a spark. There is fuel pressure in that when I cracked the union open it dripped/poured out. I wouldn't call it a 'jet' and I tightened the union before any more fuel was lost. From what I could see (and it wasn't much) the throttle cable is operating. Fuel is arriving to the cylinders (spark plugs wet and smell of fuel) but I didn't test to see if injectors are pulsing (nor did I check to see the fine mist with all plugs removed - forgot to do that test). All plugs went in dry and came out wet. Compression is as follows - cylinder 1: 5.5 bar, 2: 5.5 bar, 3: 7.2 bar, 4: 6 bar, 5: 6 bar, 6: 7.2 bar. Some of those cylinders didn't get a drop of oil in them - such was my haste. Pretty rough testing I know. Another less than scientific observation would be that the car sounds as if it has fired on at least a few cylinders (maybe a second or so) upon starting cranking, but then something has happened to inhibit(?) it continuing running. It's as if something is cutting in to stop the combustion process. Sparking will continue though for as long as the engine is cranked.
As ever, all advice is much appreciated.
As ever, all advice is much appreciated.
OK spark it good,
Fuel pressure sounds good enough
Injectors are fueling, but we connot confirm they are pulsing (could still be jammed on)
Comprssion is poor, but 7.2 bar should be enough to fire.
Compression seems low, would have expected 8 bar there abouts. A litle oil down in each cylinder could have helped that.
The fact it tried to fire for a bit and then doesnt, further makes me believe its overfueling, but could be the compression isnt good enough to make it fire.
Basically its either really badly flooded (not so common on the straight six) or there is an engine management issue thats making it over fuel, to the extent it wont fire. (thats where you scanner, when it arrives should help)
At this stage I would dry the plugs again, and add a litle oil to each cylinder. And then go for a flooded start.
Did you try the flooded start procedure when you tried to start it this time??
When it was last running, how was it and what type of drive did you do, any import will help me understand whats going on.
Fuel pressure sounds good enough
Injectors are fueling, but we connot confirm they are pulsing (could still be jammed on)
Comprssion is poor, but 7.2 bar should be enough to fire.
Compression seems low, would have expected 8 bar there abouts. A litle oil down in each cylinder could have helped that.
The fact it tried to fire for a bit and then doesnt, further makes me believe its overfueling, but could be the compression isnt good enough to make it fire.
Basically its either really badly flooded (not so common on the straight six) or there is an engine management issue thats making it over fuel, to the extent it wont fire. (thats where you scanner, when it arrives should help)
At this stage I would dry the plugs again, and add a litle oil to each cylinder. And then go for a flooded start.
Did you try the flooded start procedure when you tried to start it this time??
When it was last running, how was it and what type of drive did you do, any import will help me understand whats going on.
Cheers TT. When checking number 1 cylinder/sparkplug I cranked with no throttle. Upon checking the second cylinder I put my foot on the floor then cranked (which cuts the fuel for flooded engine - right?) All other sparks/cylinders were checked with fuel being delivered (foot off the throttle). Spark plugs have been out the car for a good few days although coils were loosely fitted over spark-plug chambers. Last week I did the foot on the floor (throttle fully open) and cranked for 20 seconds or so. Car still didn't start. Prior to that attempt the car had not been started for at least a couple of days.
I had taken the car to London and back in the middle of september (around 900 miles). Then it went for it's MOT the next week a trip of 15 miles there. It sat at the garage a couple of days until they got it MOT'd (no work done - just full of MOT bookings) and then garaged at my parents for a month. I didn't try to start it as I was doing other work on the car - front wheel bearing, removed front N/S wing, indicator lenses removed and a few other things. I made a post in another forum which will give absolutely all the info that took me up to making a post here in PH. Here's the link http://xjr6.com/forum/index.php?topic=124.0
I'd never had any problems before with it although it didn't pass the MOT - wheel bearings, emissions, bulbs.
So basically, it started fine, then I left it for a month and when I tried to start it it wouldn't run. I think I got aroung 22-24mpg on the motorway down to London and back.
That's all the info I can think of, TT.
I had taken the car to London and back in the middle of september (around 900 miles). Then it went for it's MOT the next week a trip of 15 miles there. It sat at the garage a couple of days until they got it MOT'd (no work done - just full of MOT bookings) and then garaged at my parents for a month. I didn't try to start it as I was doing other work on the car - front wheel bearing, removed front N/S wing, indicator lenses removed and a few other things. I made a post in another forum which will give absolutely all the info that took me up to making a post here in PH. Here's the link http://xjr6.com/forum/index.php?topic=124.0
I'd never had any problems before with it although it didn't pass the MOT - wheel bearings, emissions, bulbs.
So basically, it started fine, then I left it for a month and when I tried to start it it wouldn't run. I think I got aroung 22-24mpg on the motorway down to London and back.
That's all the info I can think of, TT.
Was it a short run from the garage to your parents, with a cold start and never getting fully warm??.
If yes, I Still think it could just be flooded.
Why did it fail emmisisons?? did they spot the cranked exhaust manifolds or did it not meet the standards, if you have the printout should say.
What ever caused it to fail the emmissions test could be why it wont start now,
emmissions = Engine management.
Still go for some oil down the bores and a full throttle crank, needs a really well charged battery as you have to crank for a minute or so, keep your foot hard down 100% throttle then gently lift off to say 80% and hold it there and it should fire up, if its just flooded.
Failing that you will have to read the codes and see what it says, From what you have done so far, we can rule out the favorite crank sensor and fuel pump. That leave us with coolant temp sensor and air mass as the favourites now, if it isnt just flooded.
If yes, I Still think it could just be flooded.
Why did it fail emmisisons?? did they spot the cranked exhaust manifolds or did it not meet the standards, if you have the printout should say.
What ever caused it to fail the emmissions test could be why it wont start now,
emmissions = Engine management.
Still go for some oil down the bores and a full throttle crank, needs a really well charged battery as you have to crank for a minute or so, keep your foot hard down 100% throttle then gently lift off to say 80% and hold it there and it should fire up, if its just flooded.
Failing that you will have to read the codes and see what it says, From what you have done so far, we can rule out the favorite crank sensor and fuel pump. That leave us with coolant temp sensor and air mass as the favourites now, if it isnt just flooded.
It's a good 30 mins drive from MOT station to parent's, TT. The car would have been warm and had been warmed up for the MOT test earlier that day. Print out on emissions here: http://xjr6.com/forum/index.php?topic=94.0 that link also shows also the manifolds. I'll get the battery charged up again as all it's done recently is try to start the car. Is a full minute of cranking absolutely necessary though? Last time I cranked for about 25 seconds and the -ve battery earth cable was warm, though not hot, to touch. I hadn't lifted the throttle off 100% any previous time I cranked on full throttle so I'll try that.
Thanks again.
Thanks again.
Ok, another update. I've removed all plugs and the will dry out overnight. I cranked and saw the mist of fuel rising from the plug wells. After discussing with my dad, the compression test was probably not all that accurate in that he said I didn't have the throttle opened halfway which would allow more air in (as the instructions said), the engine wasn't warm and of course I didn't put a drop of oil in all of the cylinders. It was a single gauge pressure testing device. The engine was cranked on the battery to gain a result.
As you said, TT, my dad feels the car may be over-fueling - plugs can look pretty wet when removed even after a short crank.
The scanning tool was only just despatched today so, fingers crossed, might arrive tomorrow.
As you said, TT, my dad feels the car may be over-fueling - plugs can look pretty wet when removed even after a short crank.
The scanning tool was only just despatched today so, fingers crossed, might arrive tomorrow.
Was it runing on all 6 cylinders when it went for MOT.
I looked at your emissions printout and its harendous.
HC's (hydrocarbons) should be arround 30-50 although the limit is 200, yours are 900+, that means there is bucket loads of unburn fuel in the exhaust. (again overfueling)
But and here's the funny thing, the lambda reading is 1.04, anything above lambda 1 is considered lean normally, but lambda sensor can only sence oxygen, we know its actually rich from the HC's so the only way the lambda can be so high is if there is more oxygen in the exhaust than there should be, most likely cause for that is one of the cylinders isnt firing and just pumping air through, which would give you high lambda and high HC's, hence the question, was it running on all 6.
I dont think its posible, because the pressure in the exhaust manifolds is much higher that out side, but maybe those crack are letting air in dont worry about that to much right now, but if every thing else turns up blank might come back to that, If the MOT man had seen then it would be an instant fail and they wouldnt have even done an emmisions test, so keep that heat sheild on once its all sorted.
I looked at your emissions printout and its harendous.
HC's (hydrocarbons) should be arround 30-50 although the limit is 200, yours are 900+, that means there is bucket loads of unburn fuel in the exhaust. (again overfueling)
But and here's the funny thing, the lambda reading is 1.04, anything above lambda 1 is considered lean normally, but lambda sensor can only sence oxygen, we know its actually rich from the HC's so the only way the lambda can be so high is if there is more oxygen in the exhaust than there should be, most likely cause for that is one of the cylinders isnt firing and just pumping air through, which would give you high lambda and high HC's, hence the question, was it running on all 6.
I dont think its posible, because the pressure in the exhaust manifolds is much higher that out side, but maybe those crack are letting air in dont worry about that to much right now, but if every thing else turns up blank might come back to that, If the MOT man had seen then it would be an instant fail and they wouldnt have even done an emmisions test, so keep that heat sheild on once its all sorted.
Edited by Tame Technician on Tuesday 17th November 19:14
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