I talk to my cars...won't lie to you...I want them to feel loved...and it's unconditional...I want nothing in return. I open the door,get in and ask 'How are you today?' whilst gently caressing the top of the dash or steering wheel. I start them up and allow them to warm up before venturing out....They are washed,waxed,oiled,checked,tweaked and so on and so forth...like I said I want nothing in return,they are not beholden to me and should they decide to leave they can without fear of reprisals. All that said, it would be nice if they were just a little bit less highly strung...or complex in their needs.
So it was with some,dare I say surprise, that today whilst preparing to take the X300 in question to have a wash it decided that today was the day not to start.
If you 've seen any of my other posts you'll no that this one has been a bit of a one....not its fault...it had been neglected for over three years before we rescued it and started to return it to its rightful place at the top of the food chain. Less than two weeks ago its backside was welded back into place and it basks in the glory of passing its' Mot. I subsequently drove home and proceeded to change the water pump as it was decidedly noisy. I have even changed the 'Advisory' of the offside shock absorber top bushes, that was two days ago. All this is background so you know where we're at. Today and yesterday was spent removing front wheels,cleaning and lubricating anything and replacing a missing 'wire' from one side which might be causing my 'Anti-lock' light to come on. All that aside I have not started the car for the last two weeks. Came to start it this afternoon...nothing. I have been through a number of threads for starting issues on this model so I shall try to be succinct in telling you what I have found out or done so far and what is and isn't happening. The car has always started without issue...however...I do remember on a couple of occasions having to turn the key off and back on again before the starter would engage...my previous XJ8 had done the same on a few occasions so I hadn't really paid it much attention.
So....key in the ignition,warning lights etc on..then off...turn fully...nothing. No click...no dimming..nada. I will say now that the 'Check engine' light does not stay on as, I believe, it should until the engine fires up,it disappears with all the other ones. So from reading previous threads I am lead to believe that this might be an immobiliser issue?
I have checked every last fuse,everywhere. I have checked the engine bay for lose or broken wires/connectors. I do not have any spare relays at the moment to swap out but I'm guessing that that might be the next step.?
So the question is,is there anything I can do to give me a definitive point in the right direction...Am I in the right area with regards to an immobilser problem and if so is there a way of pinpointing the problem even further?
Any suggestions,as always, will be greatly appreciated. Thanks.

 

Does everything go dark and silent when you turn it to the "crank" position?
Not trying to insult, and you've probably already checked this, but that is indicative of poor earths, poor terminal connections, flat battery, or some combination thereof.

 

Fair comment and no insult taken,everything stays lit, it's not like when you have a bad connection or low battery and you get that heavy click or clunk sound and you can tell the amps are being pulled but not enough to turn the engine,this has no response at all. As a remedial measure I have taken the battery off and put it on charge but it's only about 2 months old and had a top up charge before I put it on a few weeks ago. When we first bought the car the alternator wasn't charging so there may have been some residual damage to some part of the system that is only showing up now that we have another working alternator on.

 

Update....put freshly charged battery back on...no change...found and swapped starter relay...no change...checked connection to BPM...no change....wiggled wires and connectors down by the bank of four relays by the air filter box....engine turned over but nothing else....more wiggling of same wires/connectors...fired up....tick over has gone high (1400) but until I get chance to properly look at the wiring/connections by the relays I'll take it.
Happy days.

 

Thought I'd put up an update. My joy was short-lived. The next time of starting and we were back to the beginning. So just to re-iterate. I'm working on the presumption of an immobiliser related issue as the 'check engine' light does not remain on during ignition. It has on occasion popped on and off again but is now most definitely always off. There is no cranking at all. As a matter of course and not having any diagnostics to work with just swapping stuff in and out I have done the following. Swapped the BPM,the exciter/reader ecu,the plastic ring round the end of the barrel,the igniton part at the other end of the barrel. All associated relays and fuses have been checked and swapped as necessary.All relevant accesible connectors pulled apart,cleaned,earth straps. Removed,checked,cleaned the ecu inside the rear wing. All that done (might have forgot something) and still no closer to starting. Today,after removing the rear ecu in the inner wing (central locking and stuff I think) I thought I would check out the main eci in the drivers side footwell, pulled off the red connector and it looked ok,cleaned out all the opening in the connector and sprayed contact cleaner all over the place. As I was doing this I noticed that one of the pins was still in the connector,see the photo. I'm hoping someone might be able to point me in the direction of a schematic for the pins, the ecu is: LNA141OBE/211 Gems 6. If this is where the problem is then it's just an unlucky coincidence and I will have to dig deeper. Any ideas would be greatly appreciated. thanks.


Fourth one in from the right on the bottom row.

 

There is some doubt about an immobiliser issue, now that you've found a broken pin in the ECU. Looking at the schematic, it looks like the broken pin is #33 (White with Pink stripe wire) that carries battery voltage from the ECU to your ignition coils! A rather important link that will need repair.

A note on the starting circuit schematic says:

"All vehicles require the "Check Engine" signal input to the Body Processor Module before the Body Processor Module enables engine cranking."

Hence no crank if that CEL was not lit prior to cranking. Perhaps, when that pin was not making good contact, the ECU knew it, the CEL would not stay on before cranking, and hence the BPM would not allow cranking.

Also, your starter relay by the air box (the innermost of the four) seems to have loose connections, since you were able to get it cranking by moving the wires around. The other three relays are Wiper on/off, Wiper hi/low, and heater pump. Nothing else there that would inhibit cranking.

Keep soothing her, and she'll come around!

 

Thank you SleekJag12 for your excellent reply. I have been searching high and low,probably in all the wrong places, for a clue as to the broken pins' function. Before reading your reply I was hoping that the broken pin was the issue and not just something that had occurred during the connector removal. As everything under the dash area is still in pieces I shall be putting the original parts back in place and the will remove the main ECU with the intention of repairing the broken pin and making sure the rest of it is all good. So far this has been a process of elimination and to be honest I was running out of items to swap out before having to fault find on the wiring. I shall report findings once I have the ECU out and repaired (or replaced).Thanks again for your help.

 

So today I put everything back to original that I had replaced during testing and removed the ecu so I could see the extent of the damage etc. Below are a few photos of what I found. I plan on opening up the ecu to see if there is any internal issues as when I removed the ecu and turned it upside down a fair bit of water poured out. I can get another ecu for about £80 (a later version but compatible) which is also from a 3.2 Sport.
Looking at the corrosion and the amount of water that came out my feeling is to replace but still worth having a look. I'll post more when I get to it.


Haven't checked up close to see if any pins are stuck in this one yet.



Possibly looks worse than it is.



This is what I'm after, or the LNA1410YD/211 will also do the job.

 

The 1995 Electrical Manual can be downloaded via the "How To" quick links page. But it's well hidden.

About 5th down in the list of links there is one called "Downloads (Assorted Tech Files)". Click on that - it goes to a Mediafire page. Then choose "Jaguar Documents" and you will see the 1995 and 1996 Electrical Guides there.

Here is a link directly to the 1995 document (if this doesn't work just use the process above)

http://www.mediafire.com/file/fou1yb...e_-_JTP476.pdf




BTW - If you decide you need a new ECU - I have an LNA1410YD/211 which you can have for much less than £80. PM me if you're interested.

 

That's brilliant,thank you. Found the file as directed,perfect.I'm starting to amass a nice list of bookmarks for ease of access online as well as a folder with pdf's etc. Thanks also for the heads' up on the ecu. I shall PM you. Thanks again.

 

Another drowned ECU... dreadful. I bet it's ugly inside. But luck favors you now! Get that replacement and your troubles should be over.

 

Thought I'd put the last few pictures on of the inside of the ECU. Maybe not as bad as I thought it would be but I'm going to replace the whole unit then there won't be any lingering doubts should all not goes as planned.

 

So I've waited an extra 24hrs to fit the replacement ECU as I was out yesterday and it was to big to fit through the letter so I had to collect it today. I cleaned up the connectors as best I could,although one of the 'females' has lost a bit so I'm hoping there'll be enough left to make a good connection. Also actually found another broken/corroded pin, this time in the black connector,which was nice. The replacement ECU came courtesy of to 'b1mcp' (Big thank you) and is a superseded version (LNA1410YD/211 as oppose to LNA1410BE/211 which was the water damaged one I removed) By all accounts it should just be a straight swap. I have put the battery back on charge for a few hours so as to give everything the best possible chance...and I'm a bit nervous about turning the key. I've never had to do an ECU swap so I'm not sure if there is a procedure to follow. I've added a few more photos' and one of all the various parts I've changed so far in this saga.


Just about see where some of the connector is missing in the middle of the middle row.



This is one I'm using to replace LNA1410BE/211



In situ



All relatively inexpensive and will go into 'stock' for future diagnosis's.

 

Well ladies and gentlemen I could hold back no longer. I've just put the battery back,turned the key and........she roared back into life....no one home to share my joy but that's ok...I'm guessing the ecu will take a short while to bed as the idle was high then low and is now just under 1k but is slightly lumpY. There is also a beeping that has started since I first disconnected the old ecu (and reconnected) and replaced with the new one.It's a slightly higher pitch beep than the alarm one when you manually unlock the door and have to put the key in the ignition, also different to the beeping when you leave in gear.Hey ho.
If memory serves me right I need to take her out for a drive for a few miles to let everything settle in.
So unless anything happens possibly connected to this issue I will say thank you to all for their excellent advice,knowledge and experience...and a special thank you to 'b1mcp' for the ECU.

 

Thought I would update and you can tell me if I need to start a new thread or see this one through to the end. Took the car out this morning to try and do a few miles to let the ecu find its feet. The idle was lump to start with and it struggled to pick up the revs on the few times I restarted having stopped for parcel drop-offs,air in the tyres and the car wash. By the time I got home it was missing badly and the coolant level light had come on. I left her for about half an hour and went back to start and to try and get back on the driveway,she really struggled. I checked the coolant and the sensor that is in the bottom of the header tank was no longer attached. I push fitted it back into place but the light remains on. If you've read my previous posts you'll see that I was concerned that a couple of the connectors in the ECU connector blocks might be to corroded to much to make a connection. I'm assuming the red block connector was ok as that was the original cause of the non starting. The black connector block had a corroded connector which I think was Pin 18....(DOWNSTREAM HO2S FEEDBACK- CYLINDERS 4, 5, 6) so after getting my hand to wiggle by the connectors in the footwell and repositioning the coolant sensor she fired up well enough to get back up the drive. Questions,can I just use some epoxy resin to re-attach the sensor into the header tank and are the female connectors readily available and if so what are they called and what size are they.The picture shows the missing pins which correspond to the corroded female part of the connector. Simples.

 

Couldn't wait,thought I'd have a go at something I might be able to do. Took the expansion/header tank off. Easy to do, take the trim cover off the top of the wing and a 10mm nut is revealed,undo and pull the tank up on the left and then away to the left and it should come away,obviously any connecting pipes will need to be removed but mine were on with Jubilee clips so twas easy enough. The top pipes wept a tiny bit but gravity keeps them from losing too much fluid. If you're quick with a container for the bottom pipe then you won't waste much coolant at all. As you can see from the photo's it looks like the sensor has been stuck back in place before. I've cleaned the area on both the sensor and the opening and reseated it with a strong adhesive, being careful not to get any down the aperture the sensor protrudes into. I'll leave over night to cure

and put back on tomorrow.See what happens.
Detached coolant level sensor.



Aperture looks like its been repaired before.

 

The coolant level sensor will not contribute to the poor running/starting. Your fix above will be fine but if not put it to the bottom of your worry list.

You do need to be 100% confident in the connectors. I would suggest to get hold of a used red and black connector from a breaker (make sure they cut the loom well back) and then carefully extract the specific connectors you need and splice the individual cables a couple of inches back from the connector. If the exact connectors in the replacement plugs are similarly damaged you should be able to use any of the others - they're all the same size.


Once you're happy with the connectors, if there is still an issue I think the first thing to check will be O2 Sensor Orientation. The replacement ECU may have be set with the O2 sensors the opposite to what you have on your car. It's a programmable feature through Jag diagnostics.

The tell tale sign of reversed O2 senors is that STFT will show as maxed out +ve on one bank and maxed out -ve on the other. STFT can be checked with a simple diagnostic tool (like Torque Pro on you phone with a suitable cheap adapter).

 

Thanks for that Brendan,two faults at the same time and logic goes out the window.The ironic thing is I was toying with the idea of driving down to one of the local garages that I've used previously that are big into diagnostics to see if they'd plug her in and set her up. The garage I use for Mot's couldn't get any readings, they're diagnostics only went as far back as 2000 and wouldn't read the X300. Thanks for advice, I'll keep trawling Ebay and phone a couple of the local breakers tomorrow.

 

So I'm just spit-balling just to try and join a few dots. First, I'll pull the connectors and see if I can make good the connections beyond reasonable doubt, if no joy at the breakers I'll take one of the 'females' down to Maplins and see what they have that might do the trick. So looking at the possible bad pin I'm banking on No 18 of the black connector. Looking at the pin outs on the pdf this one is for 'Heated Oxygen sensor-Feedback Cylinders 4,5,6'...So 'b1mcp' mentioned about:
"Once you're happy with the connectors, if there is still an issue I think the first thing to check will be O2 Sensor Orientation. The replacement ECU may have be set with the O2 sensors the opposite to what you have on your car. It's a programmable feature through Jag diagnostics.

The tell tale sign of reversed O2 senors is that STFT will show as maxed out +ve on one bank and maxed out -ve on the other. STFT can be checked with a simple diagnostic tool (like Torque Pro on you phone with a suitable cheap adapter)."

The I picked up on another thread whilst researching made by XJRengineer:
"If the engine initially runs fines then starts to run very rich and stalls I would strongly suspect that the wiring to the lambda sensors has been connected back to front. You said that these sensors had been replaced, so the wiring may have been mixed up at this point. The engine ECU does not use the singals from the lambda sensors when the engine starts from cold. The ECU only uses the lambda sensors above a certain coolant temp, which couldexplain the delay before the problem arises. If the wiring is back to front 3 cylinders will run 255 too rich and 3 will run 25% too lean. This would explain the smell and the tendancy for the engine to stall."
It was uncanny as I drove for a good few miles and although it wasn't running perfectly it definitely got worse towards the end of the journey.
Am I right in assuming that that Pin No 18 would normally be sending the info back once the engine is at temperature but because we suspect there is a fault with that connection that info isn't getting sent...not sure how that works..bit above my pay grade.
Any of that make sense?

 

It should be straight forward to test whether Pin 18 is connected or not. Although in the wiring diagrams Pin 18 is marked as Input to the ECU, it is also an Output. Confusing I know.

Pin 18 is supplying a reference voltage (4.7v) to the O2 Sensor (the output). (The ECU also supplies a ground signal to the sensor on Pin 8.)

The resistance of the O2 sensor varies with oxygen content in the exhaust and the sensor grounds the reference voltage through that variable resistance. The ECU measures the voltage on the reference pin which will decrease as it is pulled to ground by the sensor (as resistance decreases). This is the input.

So you should be able to backprobe the connector for Pin 18 and measure a voltage between that pin and Pin 8 (or any gound point).

It would be best to unplug the O2 sensor at the connector on the bulkhead and then you should see 4.7v at pin 18 at the ECU and also on the Red wire at the connector (Ign On). Unplugging the sensor connector removes any possibility of grounding through the sensor so will give a more definite result for the test for Pin 18.

The exact same test should work for Pin 16 for the other sensor so you have something to calibrate your test against.

Hope this makes sense.