Didn't get a chance to look at this any more today as I was building a door latch for someone who wanted one ASAP and have another one to do tomorrow...

However, I did wonder about the heater - but the annoying thing is that the sensors aren't that old, and I bought genuine Bosch ones rather than cheap aftermarket.

If it is fine tomorrow, then I'm going to try and crawl under it and snip the wires to the LPG system where it's tapped in (I moved them to the vehicle loom side, rather than the sensor-side as they were previously) - but now I know the LPG system doesn't need them (in fact I've disabled them in the software) I'll cut the wires and see if that makes a difference.

Whilst I'm there, I'll check the connectors and make sure they are in good condition and making good contact. I'll also check the resistance of the heater circuits in the sensors to see if there is any variation between them...

Then I've got a sheet of metal to cut for my DSP amp modification, and a list of other things to work on again!

I'll update tomorrow if I get the chance to look into it, but something tells me it is something O2 sensor related...

I am also not sure the time division the nanocom records at, but I presume it's 1sec intervals.

Something had to be causing it to run rich though, as I reset the adaptive the previous time I, and recorded the fuel trims, and it was evident to see the idle trim very quickly making its way from 0.00 which was is default value, back up to about 1.46.

Also just noticed that the O2 heater status changes from ON to OFF very quickly for the period it was misfiring. And at that point the lambda output ( rather than the raw O2 voltage is showing 0 74, where I would have thought it should have been closer to 1, which is what it switches to as soon as it evens out....

I don't know if the O2 heater switching is a cause, or an effect that is happening because of something else. I'm planning on checking the O2 heater grounds just to be sure... also, shouldn't the heaters switch off when they are up to temp?

Maybe it wasn't running long enough so I didn't get it to that point.

Right,

Finally got around to having a look back at this after a day of trying to play catch up on door latch and BECM questions and enquiries...

First - Sorry about the formatting in the original post, I need to go through and add BR tags to everything where I typed it out as having a new line, so it's not as much of a jumble.

Second... Thanks for the replies thus far. I did get some live data on when it happened the other day, but I was recording the fuel trims rather than the O2 sensors. Today, I deliberately took it for a trip to the supermarket (only a couple of mins drive, but figured instead of walking like I usually do, I'd see if it did it on such a short trip and record the O2 settings on both journeys.

So - The startup from cold at home, short drive to supermarket, and shut off. O2 values are in this file:
Cold startup and drive

I think was out of the vehicle for probably 10 minutes, and then recorded the startup again. It did it again, and a couple of the misfires almost made it feel like it was going to stall... It started OK - Idled at it's normal 1K rpm for a 10 sec or so (which again is apparently normal on the Thor models) and then it settled down to normal idle speed, and then started acting up. About 20-30 seconds later, with like the flick of a switch it started idling properly again and smooth all the way home. When I pulled up at the house, it was idling at proper speed, no sign of a misfire.

Incidentally, there were no misfire codes logged in the engine ECU - there was only codes for mixture adaptations out of range 'fault occured 1 times, not currently present'.

The O2 live data from the hot start and run back home is below:
Hot restart and drive

Sadly there is no other engine data apart from the O2 sensors, as the nanocom only seems to record what's in the current page of inputs, not a full spread of everything, which would be a bit more useful in this case.

I can add the file I did the other day with the MAF level and fuel trims etc. but it doesn't have O2 data and was from a slightly longer journey, but the startup symptoms are the same.

I don't think it's LPG related as the journey I did today, I switched the LPG off so it was just running on petrol, and the previous time it did it, I reset the adaptive values (in case the LPG had been affecting it) and then did the journey on petrol aswell - and it still did it on hot restart.

Thanks Richard for the idea on the purge valve - I will look into this tomorrow.

Let me know if you see anything obvious in the log files - I'm about to have a thorough look through them myself as I've only just had the time to get them off the Nanocom and convert from CSV to Excel sheets.

Cheers again,

Marty

EDIT: Have reformatted the original post. Also to add, my LPG system is Zavoli Alisei multipoint, with Hana 2002 Gold injectors.

The temp sensor location move was pre-'Thor' days, so your ambient temp sensor should be down in front of the radiator, just inside the LH chassis rail (the bracket is bolted using the bolts for the crash can).

A copy/paste from RAVE about the ambient temp sensor: (as it's easier than typing it out!)

Ambient Sensor <br>
This sensor measures the temperature of the
external air flow into the vehicle. <br>
For vehicles with VIN’s up to 381430: <br>
The ambient temperature sensor is located behind the
drivers side of the fascia. <br><br>
For vehicles with VIN’s from 381431: <br>
The ambient temperature sensor is located behind the
LH side of the vehicle in front of the condenser. The
revised location improves the response time of the
sensor. The new HEVAC software will not update the
ambient temperature sensor readings unless the
vehicle is travelling over approximately 15 mph (25
km/h). The HEVAC software will therefore not auto-matically
correct temperature readings when a faulty
ambient temperature sensor is renewed.

That was taken from the '97 edition of the ETM - so I think is somewhere in the '97/'98 MY - as it has an amendment at listed at the start of the ETM dated 02/98 with one of the changes relating to the ambient temp sensor location. So your vehicle should definitely have it moved... I was close on the delay for using the temperature reading - but instead of a timeout, it goes on vehicle speed so it knows it's getting a fresh air supply over it before it uses the value for any calculations.

Re A/C - again Thor models had the updated wiring installed in the vehicle loom with RL10 and F27 used to drive the AC compressor, and the HEVAC wired directly to the relay, via the trinary switch, so if it isn't working then there is either: No gas, dodgy trinary switch, dodgy AC Compressor, or a leak somewhere.

You can unplug and jumper the trinary switch to force the compressor to run - to either diagnose/rule it out and then it comes back to the switch, gas, or leak :)

Marty

As GilbertD says...

In fact 12mA is very good for it when it's asleep... I think the documentation reckons on about 30mA.
It should quite happily sleep with doors, bonnet etc open... I had one testing on the bench today with nothing but the essentials plugged in, so pretty much every input was showing incorrect as they weren't there, and it still went to sleep on me whilst I was looking up some data on the PC.

I'd have to have a look into a circuit for driving another LED off the gear shift - but the thing with doing it that way, is the LED will illuminate whenever the shifter is in that position (park for example) and the ignition is on.

I seem to remember when I had mine apart to change the LEDs about (changed the colours) that it looked like a few of them were all commoned up in a strange way (I didn't draw the diagram out but it would probably make more sense to me now if I looked at it again!). That being said, you can get 'normal' LEDs which aren't the 'superbright' versions that only draw 1 or 2mA when lit up - so you may even be able to tap one straight off the original one. Failing that, you could probably use the signal to the LED in the shifter as a trigger wire for a transistor, which then drives the additional LED.

The perhaps most annoying thing about the MK3 receiver being so expensive is the fact it actually works... which sounds like a back to front statement, I know - but as much as I loathed to pay nearly £200 for it a few years ago, because there is no reason for it to be that expensive, and also in my eyes, LR knew about the problems BEFORE the P38 production was finished and only released the MK3 in 2005(ish) - it should in my mind have been a recall item or at least discounted item since they knew about the problem and didn't fix it with the MK2 receiver!

Still, as much as paying the money for it went against my thoughts of JLR company greed - it has to be one of the best investments I've made for the RR - as I've travelled so much for work that it often sits 1,2 even 3 weeks at a time outside the house whilst I'm away and every time I come back and she starts up. The real test will be when I'm away out in China working for 8/9 weeks in a couple of months... if she starts up when I get back (on a 4yr old battery aswell) then I'll be a happy man!

I'm not saying rush out and buy one... but if you are planning on keeping the RR for the foreseeable future, then it may be a wise investment - just in not having to deal with flat batteries or having to keep it on trickle charge all the time etc. Either that, or there are loads of advocates on one of the other forums for putting a cheap 433mhz relay in the power feed to the RF receiver, so then you have another fob to switch the power on/off to the receiver, and then the vehicle fob to unlock. I can see the point of it being a cheap fix, but it's too much of a bodge for my liking - plus it's another fob to lose!

Marty

Right, my turn to ask a question... and figured I'd post up here before the 'other place'...

2001, 4.6 Thor engine - petrol and LPG.
If I start it from cold, it runs fine - idles about 1200rpm for 20-30 seconds and then idle drops back to about 1000rpm, and then down to normal (seems to be normal behaviour for the Motronic 'cold start' strategy or that's what the manual said anyway! <br>

My problem is if I then hot start it - say go to the supermarket, and come back 10-15min later. Did it today and it had sat for 5min... It will start fine, and idle for a few seconds and then go lumpy and misfire for about 30-45 seconds (I presume until it goes back into closed loop). Then once it's had it's little tantrum, it will run, and idle sweetly on both petrol and gas. <br>

A brief run down of the engine/what I've done to it over the last few years since I've had it: <br>
First bought it and has misfiring at idle - all the time, petrol and gas. Changed TPS, CKS, HT leads and eventually tracked it down to a faulty MAF sensor. Replaced it with aftermarket and problem solved.. ish. <br>
It then ran fine, but every now and again I'd read the codes and the fuel trims would be jammed to max, I could reset adaptives and it would all be fine but over time would get skewed again. Ended up buying a genuine Bosch MAF and replacing the aftermarket Bearmach one - and problem solved. MAF is now about 2yrs old. <br>
Been poking about with the LPG and injectors/plumbing and all that so ran it on Petrol for a fair amount of time and trims seemed pretty stable, no recurring faults in the ECU. <br>
Over last 6 months or so (bearing in mind I'm away a lot and it doesn't get used - so 6 months is probably 1000 miles tops) it's been doing this when restarting the vehicle hot. <br>
Things that have been replaced in the last few years: <br>
MAF (Bearmach aftermarket, and then genuine Bosch circa 2014) <br>
TPS (aftermarket - 2012) <br>
CKS (Genuine LR - 2012) <br>
Spark Plugs (Changed at regular service Jan 2012 when I bought it, and then circa 2014 I changed them for NGK BPR6ES) <br>
HT Leads (Changed first in 2012 as regular service item, then circa 2014 I changed them for Magnecore KV85 HT Leads) <br>
Coil Packs (Changed circa 2104 with Magnecores and NGK's - Genuine Bosch replacement units) <br>
O2 sensors (Changed 2015 for Genuine Bosch sensors - partly preventative maintenance and partly due to LPG system being tapped into them and I was getting the odd O2 signal missing error in the engine ECU - LPG system had been connected on the sensor wiring side and on one side was just 'twisted and taped' so decided it was worth just replacing them!) <br>
IACV has previously been cleaned but it doesn't coke up like the GEMS one does either. <br>

My current thoughts... <br>
I have another genuine Bosch MAF so thinking about swapping that just to rule it in/out. I don't think it's the MAF as the symptoms of my problems before were bad idle all the time, not just on a hot start. <br>
I haven't yet chopped the O2 sensor wires off that feed the LPG system... now I know they aren't needed for anything the plan is to disconnect them altogether. I don't know if the LPG system is somehow interfering with it - but it feels like the problem is in the 'open loop' fuelling before it switches over to closed loop. <br>
I've looked at live data on Nanocom and the MAF reading looks to be fairly normal - however very quickly after I had reset adaptive values, the 'idle trim' fuel trims had shot from the reset value of 0.00 back up to about 1,46 where they were before. Other fuel trims are looking pretty close to 1.00 <br>
I don't think it's likely to be plugs, leads, coils - and as such haven't yet pulled the plugs out to check them - but if people think it's worth doing, then I'll do that in the next couple of days. <br>
I haven't tested fuel pressure - but I don't think it's the in tank pump as it has no trouble starting, and after it hits closed loop, it runs sweetly. <br>

Any ideas/thoughts/things to try? I've had the upper plenum off a few times when doing the LPG bits - and have resused the tin gasket a couple of times - but it's always been cleaned off and then re-sealed with a thin smear of black RTV. What's best to use if I want to spray something around the inlet to see if there is a vacuum leak into the manifold, post MAF? Easy start or something like that? <br>

I've decided I want to get it sorted this month as I have some time at home and want to catch up on some of the maintenance on it, even though it hasn't done a lot of mileage, but I'm likely to be using it more and it pisses me off when I'm out and about to have it idling so rough when I start it up - even if it is only for a short period of time! <br>

Cheers, <br>
Marty

No problem - I had it all in bits anyway, so didn't take me long to trace it down.

Wiring... I think you would be pretty unlucky if it's a wiring break, as from memory there aren't any additional connectors between the cluster and the HEVAC on the dimmer line for the LCD as it's all in the fascia loom. But it doesn't mean a pin hasn't backed out of either of the connectors or something simple like that.

I can't fully remember the 'hot start fix' but something tickles in the back of my mind that this has something to do with the position of the ambient temperature sensor being moved from the inlet of the LH blower housing to down by the front of the radiator. And it was just something along the lines of a short 'time out' period where it ignored the external temp sensor reading to allow for latent heat from the engine affecting the reading.

I'll see if I can find the actual documentation on it... I would imagine the older one would have an issue though with the AC compressor clutch drive - as the earlier HEVAC units would drive the clutch directly, so would expect to have a load on the AC Clutch pin (which is why when you put in the upgrade harness to power the clutch off a battery feed via a relay driven from the HEVAC you need to put a power resistor in as a 'dummy' load so it doesn't throw a fault) - whereas the later models had the extra relay and fuse in the underbonnet fuse box - so I presume the later version of software just had this 'error' condition deleted so they could just drive a relay and not have to put in a big resistor into the factory wiring loom...

You might be able to get away with swapping just the whole front panel and PCB between the 2 units... all the driver components for the backlight are on the front panel PCB and then have a direct link through the ribbon cable to the HEVAC connector to the fascia loom. The chip with the software is on the bottom board with all the driver chips and all that... So I don't see a reason why you can't use the older front panel with the newer main board and have the best of both worlds... And then I'll buy the old faulty one off you to try and repair it and do the LCD fix and all that if/when I get some of these connector strips

Let us know how you get on...
Marty

Well, Have had a bit of time today to have a look at my HEVAC screen fix, and the good news is that it works a treat.

The bad news is that the supplier I got this from on eBay sells them from France @ 20 Euro a pop.. which to me is a little bit steep for what is probably a few quid's worth of connector. So I've going to see if I can go direct to China or somewhere like that and get a bunch of them made, so I can then hopefully either offer them cheaper (for the DIY'ers out there) or offer a HEVAC screen repair service to tack onto the other bits I do...

You can see all the pixels now.. it probably has logged nearly every error under the sun as I was powering it up on the bench with none of the motors/sensors connected...

So then I started looking into the backlight and have found the positive for the backlight goes off to a small transistor on the board - it's T005 in the picture below

I am still working on tracing it from there back, but I would say it's the first place to go looking if the backlight isn't powering at all.

I'm going to look up the part number for it and also availability on replacement units. I'll let you know when I've found where it traces back to and if there are any other possible failure points.

Marty

Edit - just to add that tracing the transistor wiring... The feed comes in on pin 11 on the big black connector on the main PCB as an inverse PWM signal from the instrument cluster. This then ends up on one side of D020, going through that to R047, which is 6.8K ohms. The other side of R047 goes to one side of R046 (10K ohms) and to the bottom/left pin of the transistor T005. Bottom/right pin appears to be the power and top tab + bottom/centre pin are joined and are the output drive to the lamp itself.

T005 appears to work out as an Infineon BCX69-25 small power transistor.

I haven't forgotten about looking into this... been caught up today with a few other things and been out this afternoon giving Snog a bath (though I missed a few bits by the look of it, but it's so hard to see where you've brushed on black paint when it's wet!

Also now got 2 of my 3 keys... only taken about 10 weeks... but they reckon the 3rd one is due in a couple of days which is nice... A bit of a mental relief to have a spare key for my one now!

I'll be popping back down to the garage a bit later to try out this HEVAC screen fix so will have a poke about on the board then and see if I can find out how the backlight is driven.

Marty

Sorry - a bit late to the party... Been repairing a logic board for Ray in Canada..

What's wrong/not working with the BECM? If it's a power board problem then they are generally fairly easy to rectify - either fixing the original board or swapping it out for a known-working one...

If you go to the website, you can drop me a query off that and it will then come through to my email - it's probably a better way of getting in touch with me as I sometimes forget to come on here and I don't get notifications of private messages via email either...

Either way - I'm sure we can sort something out.

Marty

mm, technically the diff/axle was from part of the joint thing with my mate, and since he had nothing to do with the buying of the ball joints, replacing of them, or the install of it with me and you onto your vehicle the folding stuff went in my pocket to reimburse me for the cost of the parts and my time to do the ball joints/help you swap the axle. But as you say - that diff is probably all fine (not that I was bothered if it wasn't - as far as I was concerned I was happy to swap the axle for nothing as it had been there so long! Funnily enough your old axle hasn't moved from where we left it anyway!

311K on the clock must be one of the highest for P38's out there.. it's almost double what's on mine - though I did take it out for a nice cruise today - and swung past the Land Rover dealer to pick up 2 of the 3 new keys.. it's nice to have the spare for mine now!

Can't hurt to put a new set in though with the kind of miles you put on it... you nearly do more in one trip to France than I do in a year! If it's any consolation, I got told off by my mate for giving you the axle as a straight swap with that front diff as he seemed to think that it probably wasn't that old and was planning on using it in his own P38..

My answer however was that it has been sitting there for the best part of a couple of years now with nothing happening to it, and as far as I was concerned it was going to be sent off as core to someone like Ashcrofts anyway...

I'm not sure on the exact way the gearshift indicator works - but I presume it to be PWM as the LED's are dimmed on the range that isn't currently in use - so if you go to low range for example, then the high range markers will go dimmer (especially at night I think when the instrument lights are on). So you could possibly pick up the feed from one of the LED's, and then build something to make that drive a brighter LED.

Also it is worth remembering that especially on the later P38's the door doesn't actually need to be closed for the BECM to go to sleep. So if you are just wanting to stay with it for a bit and see if it's sleeping then you can do it with the door open (or sit in it and close the door - again it doesn't need to be locked - it should still timeout after 2 minutes anyway).

The other thought I have had would be to see about putting a current measuring device on the power line from the battery to the fuse box and then set that to have a trigger point of say 100ma so when it goes above that it turns an LED on. There must be ways of doing it on something like an Arduino with a non-contacting current clamp and then using that to read the draw.

You could look at clock pulses off one of the serial lines - but I haven't delved into them enough to know whether these actually stop when the BECM goes to sleep - I don't think they will as there are serial lines still to the door outstations that must be active when it's asleep so it knows if the key has been turned in the door for example.

If you were wanting to go from the LED in the gear shift, then you will have to do a bit of probing and see how the BECM illuminates that lamp, as it only interfaces with the H gate on a few wires:
White (Pin 2 at H Gate) Power feed from F6
Red/Blue (pin 9) - Illumination (spliced off other interior lamps)
Brown/Yellow (pin 8) - High Range Status - splices to BECM/Autobox ECU/Transfer Case ECU
Brown/Red (pin 11) - Low Range Status - splices to BECM/Autobox ECU/Transfer Case ECU
Yellow/Green (pin 6) MES1 line (to determine Normal/Sport/Manual mode) - splices to BECM/Autobox ECU Works on truth table with MES2
Yellow/Red) (pin 7) MES2 line (to determine Normal/Sport/Manual mode) - splices to BECM/Autobox ECU Works on truth table with MES1
Blue/Green (pin 3) - 'Z' switch from geabox XYZ switch - splices to BECM/Autobox ECU
Blue/Purple (pin 4) - 'Y' switch from geabox XYZ switch - splices to BECM/Autobox ECU
Blue/Black (pin 5) - 'X' switch from geabox XYZ switch - splices to BECM/Autobox ECU

So there are a lot of shared lines with other ECU's aswell, but there must be one of them that the BECM uses to illuminate the 'gear dot' - note the telltale will illuminate next to any gear that is selected - say you left it in drive or neutral, then the BECM will have the glow on that LED - it isn't always the 'park' LED.

Bit more food for thought!

From memory the HEVAC LCD lamp uses an inverse PWM signal from the instrument cluster to control the brightness when the side lights are turned on... but that being said it should be on all the time in some degree so that you can see what's going on the display (or at least see how many dead pixels there are!!)

If it's not working at all then it could be the driver transistor (as I'm sure it probably has one!) has gone faulty or there is a bad connection somewhere.

I'm planning on playing with a couple of HEVACs over the weekend as I have a LCD Pixel repair kit that I've bought and want to try out. If it works, then I'm going to see about getting a load of them in bulk and hopefully add that to the list of bits that I repair/rebuild...

But whilst I'm in there, I will see if I can come across anything that might cause the backlight not to illuminate at all.

Marty

Unfortunately by then it was about a month after I had received the order when I actually got to open it.... I had been away working and ordered the parts to (hopefully) arrive before I was due to go away so I would be able to have done the water pump aswell, and then not have to rush later... Parts didn't turn up before I left (again usually they have been really good - if things are in stock, which all my items were at the time, then they are usually there next day... and I'd left an extra day spare, but this time didn't turn up as quickly).

I tried calling them about it when I did return home and open the box, but got no answer on the phone, and I had to get the water pump done that day as I was having to drive somewhere that night for work, returning the next day, and then buggering off to Europe again the following day, so I ended up getting one from the local LR independent place so I could do the job.

My next order with Island 4x4 also wasn't great - there were a couple of parts that were 'to order' plus a couple of days... fine.. no problem.. but I then had to chase them up after a week to finally be told that the part I had ordered wasn't available from their supplier and they didn't have one of the other items in stock either (valve grinding stick - I tacked a few other tools onto the order to take it up to £50 to qualify for free shipping!).. Which is fine, if you don't have the parts, then no problem - but I shouldn't have to chase them up for an update a week or more down the line.

A bit like trying to deal with Land Rover themselves... ordered new keys for my P38 and the 2 restoration ones which had the keys nicked from the workshop.. on the 23rd DECEMBER... and trying to get any answers out of my dealer is like getting blood from a stone. I've called them 3 times now, and every time they have vowed to get in touch with JLR and call me back 'that afternoon' .. and every time have failed to call me back. Now it's been nearly 8 weeks, I've very tempted to walk into the dealer and ask to see the manager and ask if I would have had the same treatment if I'd walked in there to spank away £75K on a new RR, or if it's only because I've ordered 3 items for a 15+ year old vehicle that I'm being given shit service...

Pads shouldn't be too bad to change... the shocks are pretty quick to change on the front - but still not fun in the rain!

I know what you mean about the Island 4x4 website - though I haven't ordered from them again since the last time they sent out my new OEM waterpump loose, and the gasket box taped in the top of the box, which was subsequently torn in one place and the tape damaged the surface where it had gone across. Previously to the last couple of orders I wouldn't go anywhere else, but the last 2 orders have left me with a bit to be desired!

I will probably order from them again at some point as they do seem to be cheaper than most places - even for OEM parts...

Ok, you had me at flashing... well that and key fob...

I'm away working at the moment and haven't had my laptop on in the last couple of days - but I'm about at the weekend so will check back in then and hopefully be able to answer any questions :)

I would say that the difference between the 3.5 and 3.54 would be minimal, but I wouldn't recommend doing just the one end!! Would probably toast the viscous coupling before moving to the rear diff... but who knows what the outcome would be after that!!

I like the colour of the new one!!

Maybe yours was one of the first Bosch versions brought out by Land Rover - or if it was owned by LR for the first 2 years of it's life, then it could be a 'pre production' model for the Bosch system... AFAIK all Bosch versions came with side air bags, so it's in line with the rest of the spec.

I also have a problem... now owning 3 of them... I really have to start getting some work done on them but since I have the most of March off, I am hoping to start getting stuck in!

Drop me the VIN number of the new one if you want and I can have a look at it in Microcat and see if it has any of the build options listed!

Yeah, the rear is a nice piece of cake compares to the front... especially as the hubs have never been apart before!!

I think there is an option on the P38 front diff on the Ashcroft transmissions website to upgrade the diff centre from 2 pin to 4 pin - so I presume that they just fit a 'standard' front ring & pinion to the 4 pin centre... Extra £50 on top, plus apparently an extra charge if you then return a 2 pin unit - so I'm guessing somewhere in the £100 region on top to make the front one a correct 4 pin diff...

Also looks like they do 'HD' ring an Pinions in a 3.5 ratio (close enough to the stock 3.54) which are selectable for front/rear if you wanted to upgrade yourself just those components for a cool £195 an end!!