Oy Miles, Simon, yer both barrred!

Morat wrote:

The good news is that the bottom end is fine :) The issue is that the engine doesn't run on petrol or LPG properly when warm (fine when cold) but if I disconnect petrol injector #2 it runs on 5 on petrol and perfectly well on gas at all temps. So for now it runs on 5 until switchover and then it's all fine. I've no idea what to do about it, but you might be getting a visit! :)

Despite cleaning some of the more obvious engine grounds with a wire brush and switch cleaner before re-attaching them without much effect I'm still clinging to the theory that it's an earth issue. The radio develops a nice crackle which appears to be engine speed related and the gearbox can get sulky on a hot day. That's definitely electrical as it changes fine when you use the gear lever.

Just to say that Morat visited again the other day and I had another look at the Jeep. Found cyl 2 to be OK (Miles recently replaced number 2 petrol injector) but cyl 5 won't run on petrol, this seems to be because petrol injector 5 won't open - An injector issue not electrical issue as other cylinders will run OK if connected to cyl5 injector plug and all cylinders run OK on LPG (as long as in open loop mode..). There's also a problem with the pre-cat lambda probe, it's reading very rich (1.2volts) almost all the time which is forcing the engine to run lean due to fuel trims going full negative when it's running closed loop. It seems Miles found it runs better with a petrol injector unplugged because this immediately forces the engine to run in open loop mode thus preventing fuelling becoming too lean due to the lambda issue. One aspect of this model Jeep is that they don't switch to closed loop mode until they see lambda voltage fall to below around 0.8volts during the warm-up period (cold start extra fuelling is leaned off during the warm-up period in the usual way until a lean lambda reading then triggers closed loop mode), it took me a while to get the engine to switch to closed loop mode (because lambda read rich almost all the time but just occasionally dropped to reflect normal/lean voltage on over-run) but closed loop operation leading to very lean running then brought about the drive-ability problems. I have known bad petrol ECU's on Jeeps (interpret readings from sensors incorrectly etc) but I directly measured lambda voltage and it was the same as the ECU reading. Miles is going to swap pinj5 and fit a new lambda, I expect it should be OK then.

Don't own any Rangerover and never have but I've driven lots of Classics, hundreds of P38s and hundreds of L322s.
I don't get much of a sense of occasion when entering/driving any vehicle these days due to driving so many vehicles as part of my job, but I sometimes get just a bit of a sense of occasion when getting into a P38 (any really but especially a nice one) that I don't get with L322s regardless of spec. P38s have a lot of character, there's not much else like them.
Prefer the cabin of a P38 over an L322 and, dunno if this will seem strange, P38s seem more comfortable than L322s for the first hour or so but L322s seem more comfortable after then. The L322 cabin is similar to most other upmarket fairly modern cars, a P38 probably still seems a bit more special because it was/still is special.
Sacrilegious bit - The other year I needed to buy a towcar at very short notice to pull the caravan, it couldn't be a P38 because it had to have 7 seats. Could have bought a Disco but didn't even look at them, instead I bought an ML 7 seater. Not much of a Disco fan anyway but tbh I'd much rather trust an ML to pull a caravan hundreds of miles almost immediately after a short test drive than a Disco or a P38 after just a short test drive.. on the basis if the ML seemed OK on a test drive it would hang together over the holiday, most common problems with them develop slowly and they have less to go wrong. Dunno how I'd feel about buying an L322 after a short test drive and immediately using it for holiday towing, probably a bit more confident than a P38 not as confident as with the ML but L322's were out anyway as again not enough seats (and more expensive). If I'd had more time between buying and the holiday and didn't need 7 seats I'd have gone for a P38 and confidently used it for any purpose after it'd proved to be a good 'un or I'd sorted any problems.
Don't think there can be much doubt that the BMW V8 is miles ahead of Rover V8s.. being a pushrod engine the Rover is far easier to put right if it does go wrong but seems to go wrong at fewer miles than the BMW engine.

To clarify - When it feels like it's running on less than 8 cylinders happens on petrol? You say this happens when it's just gone into 4th gear ? Unless the problem is gearbox related it won't just happen in 4th gear so try to find the conditions for the engine when this happens... Is it for example after gentle / moderate / hard acceleration to (say) 40mph and have backed off the throttle to continue at said 40mph, so when the engine is under less load and at lower rpm after acceleration? Does the same happen regardless of hot/cold engine? What happens if you don't back off the throttle but continue accelerating in 2nd/3rd/4th gear? If fault is really only in 4th gear then problem might actually be gbox related, I've driven plenty automatic cars where the engine lacked torque in certain conditions because the gbox ECU sensed gbox clutch slippage and instructed the engine ECU to retard ignition timing to reduce torque... Talk engine conditions not gbox conditions unless it really only does happen in 4th gear.
Probably jumping the gun a bit but assuming the above happens on petrol, does the LPG system always shut off after 15 seconds or does 15 seconds just coincide with getting into 4th gear? In which case the LPG system might be shutting off if it senses loss of rpm pulse or petrol injector pulse. Does it really feel like it's on 7 or 6 cylinders (with engine vibration and missing exhaust sound) or just down on power? There could be correlation between misfires (for electrical reasons) and the LPG system shutting off.
Would've just blanked the evap purge valve off.

Did a write up on it on LPGforum here's the link

Been wondering if the push in pipes at the evap end are some standard size and if I could get some from a scrap car to connect to hydraulic lines somehow. The bits of pipe left on my evap end fitting are probably too short and curved to connect anything to.

Should really upload some pics and link to them here, I've already uploaded pics directly to an Elgrand forum but internet here is acting up today and I'm short on time. https://forum.elgrandoc.uk/threads/e51-rear-aircon-leak.3203/

Morat wrote:

started leaking from the reservoir after a week.

Look on the bright side Miles, still better than if the noise was coming from the engine's bottom end lol!
Tried these http://acdoflancashire.co.uk/ ?
Maybe the Chinese merged the Yank PAS pump design with a Merc PAS pump design.. leaking reservoirs is a common Merc problem. Dunno why firms like Merc design their own bits such as PAS pumps only to make a less reliable part than well proven generic stuff that would've probably cost them less than their own design.

The aircon connectors arrived so without checking I think they only came from Manchester and cost £7, seem to remember seeing them on EBay from Singapore for less than £3. I bought the brazing rods from Machine Mart Doncaster for about £35 or £40 (so very similar price to that you paid Bri).

When I get time I'll try my option 3 (in my last post) and if that doesn't work (I think unlikely it will) I've thought of an option 4... Measure it all up and see if I can get a hydraulics firm to make full length rubber/flexible separate lines for LP and HP. But could a hydraulics firm get the fitting that goes into the rear evaporator right? They're not screw on hydraulic fittings, just smooth pipes with O rings, just push in and are clamped from behind by a plate that is secured by a bolt between the pipe holes.

BrianH wrote:

Couple of quid is a vast improvement over the £40 odd they had shot upto. I think the ones i brought were around £20 at the time, but they appear to have become much more scarce to find now.
https://www.ebay.co.uk/itm/R134a-Auto-Quick-Coupler-Bass-Adapters-Low-High-Side-AC-Manifold-New-SU/183151899017?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649

That's what I bought. Dunno where I got Singapore from lol, must have seen Singapore on another listing. Would have just bought another charge kit from Halfords rather than pay £40 for the bare port connectors, won't need the HP connector without a proper AC machine anyway.

I wonder if an LPG thermistor would be any good? They usually have the negative temp coefficient and are made in many various specs, 4.7K is very common, usually very cheap.

Took me a while to find the leak, it's not on the thick single pipe (with inner pipe) section, it's in an area where the single pipe has split into two pipes just a few inches before it enters the rear evaporator, the leak is on a short tightly curved section of the smaller diameter higher pressure pipe. I did order a couple of AC connectors as Bri suggested but they'll be ages before they arrive (from Singapore, just a couple of quid including shipping) so I cut my Halfords recharge kit pipe in half and attached the bit with the AC low pressure connector to a tyre valve, used compressed air to pressurise the system as Gllbert suggested. At 160 psi there was only a very slight weep of green fluorescent stuff from the narrow pipe but when I ran the AC compressor the weep turned into quite a spray. Seems the pipe has corroded / been damaged by eletrolysis from touching a metal panel while damp. On the vast majority of this model vehicle the front to rear AC pipe is one long section, on mine it comprises 3 sections. The 3 section is apparently only ever an aftermarket replacement part, to replace the original single pipe like for like the rear subframe has to be lowered but that isn't necessary with the 3 section aftermarket replacement. Disconnecting the rearmost section (with the leak) from the evaporator was a pain, the single M6 bolt that secures both HP and LP pipes had also suffered corrosion and snapped in half. Still, I managed to disconnect the pipes, then tried putting a couple of nuts on the broken bolt to torque up against each other to try to unscrew the bolt again... snapped again. I managed to drill the bolt out and re-tap the threads, so now I'm hoping I haven't damaged the evaporator by drilling.

With the rear section off I was able to better clean it up, which is when I found just how corroded it was. Still there were only a couple of little pin-prick holes so I set about trying to braze it over and thicken it up. At first the results looked really promising.. and I should probably have left it at that but I didn't! I realised that although it looked repaired I hadn't 'scratched it in' so had a go at reheating and scratching in... which is when the massive holes appeared lol! Then I tried cutting the corroded section out and brazing a bit of tightly bent 8mm copper pipe in it's place using 8mm internal diameter pipe nuts at each end rather than trying to braze copper to aluminium end on. No luck with that either and at this point it was 10pm and time I packed in.

I now have a few options - 1 drop the rear suspension and fit a full length pipe from a scappers, 2. try to source a second hand or new rear section for my 3 section setup, 3. try again to repair this pipe... Might as well try 3 first, won't hurt to try. But I'll try another tack using aluminium aircon pipe cut from a car that I'm going to scrap. One of the problems with 3 is the shape and length of the pipe, I'll have to really tightly bend the scrap AC pipe and don't know whether to still go with the pipe nut type idea or just try to butt braze the pipes together. I imagine butt brazing is extremely difficult!

I do wonder if brazing was a bad idea... If I could have used something like that two-part metal repair stuff instead, perhaps coated with a layer of TigerSeal and Jclips over the TigerSeal after it had set.

I'll add some pics when I get time.

Are the limited editions worth a lot of money?

The splice could work, not seen those before. I'll have to see where the leak is first and check diameter, not measured it but seems wider than 3/4"

I think Hugh mentioned incorrect idle speed when he brought it in for conversion?

I slackened the cruise cable which was tight. Even so, not sure if the throttle body spring is closing the throttle fully.

I'm on a few forums and only one of them allows uploading pics directly.

Clicked on this thread curious about what H&H is, thought it might be about old stage amplifiers... I'm not the most clued up person on Rangerover specs here lol.

Thanks Clive and Bri.

In the vids they just keep testing to see if the rods will melt when they touch the aluminium, though I take your point about a thin pipe could be cool at the edges but quickly get too hot and melt where heated. I picture going up and down quite a length of the pipe heating quite an area around the leak while testing with rods to prevent overheating a small area. Yet to see if it'll work lol!

Couldn't slide anything like a pipe over the outer AC pipe because it's in sections with wide fittings at each end, couldn't cut it to slide anything from the cut side because it has the inner pipe. .

Usually less pressure on the low side of an AC pump when running than there is with AC system turned off?

Seems plenty firms will recharge AC but very few will get involved in fixing it. Years ago I had a problem with AC on a Grand Voyager, it failed the vac hold test at Charlie Browns. Staff there pointed me to a guy next door who they said could repair AC systems so I left it with him for the day expecting him to stick fluorescent dye in it and tell me exactly where the leak was. When I returned he hadn't found the leak or put any dye in it, he simply told me there was a leak somewhere on it. Heated argument and I wouldn't pay him... WTF did he think I'd gone to him for when Charlie Browns told me the same very basic info for free. Think he just thought he'd chance having my trousers down, no chance lol. I really have a problem with people who do that sort of thing, there are plenty like it in the field of LPG too.

BrianH wrote:

You definitely don't want to inhale r134 via a heat source (eg a cigarette) it does something nasty, not sure its just carcinogenic I seem to remember there is other risks. This seems to suggest its poisonous in that state > https://www.hella.com/techworld/uk/Technical/Car-air-conditioning/Car-refrigerant-oil-filling-quantities-2114/#

That's me buggered then lol!

I do have a car here with charged AC system that will be scrapped at some point so could make sense to do as you say with the pipe between cars, I plan on cutting some AC pipe from it to practise brazing with. Still I suppose I'd need to make up the line to connect cars and the AC system on the car to be repaired will be open to the elements when I remove the pipe to fix it. How did you make the line Bri and does it run between low pressure ports or high to low port?

Thanks for replies. I probably won't connect another cars's AC system to this car's, don't have a vehicle with a running engine (to run compressor) to scrap and depleting a good car's AC charge defeats the object when could just put a partial charge in from a Halfords bottle without having to buy/make a long line. Something to remember though and I'll probably try this sometime in future in a different situation.

I saw some other videos on Youtube that make brazing the AC pipes look similarly easy as in the MachineMart video but on thin AC pipes, the surface tension of the melted rods almost magically spanning and filling holes without filling the pipe with braze... which is what I'd need because the pipe I need to fix has another pipe running inside it (visibly one pipe runs to rear AC because the second pipe runs inside it), don't want to fill the void between interior and exterior pipes.

Started with doubts about how well a brazed repair would hold, then on how difficult it would be to do the job (skill). The videos made me more confident in both respects, now still confident on braze effectiveness but a bit less confident in terms of skill, Clive's points agreed with my initial doubts. I will be trying it and if I can't fix the pipe could maybe lower ambition and braze the inny-outy pipe shut so at least the front AC will work or increase ambition and run two pipes to a different rear evaporator. Seen some videos where they make brazing fittings (such as for crimping rubber AC pipes to) onto AC pipes look even easier than repairing holes..

Different connections, also I think R134 has a higher working pressure than propane or R12 systems so an R134 system might not work on propane even if the seals don't fail?

Seals failing are reason I now won't pressure test with LPG... I'm surprised I was lax on that, thanks!

Still the hypothetical scenario where someone turns up at an AC shop with a none working R132 system full of LPG... Must have happened to someone, I was considering taking the AC fill pipe off the Halfords kit and connecting to an LPG source to pressure test, others will have read a bit on the net about some AC systems using propane and thought of chancing filling their system from a Calor bottle (maybe not to leak test but to recharge). What happens regards the AC machine and if the machine is broken what are the AC mans options (machine warranty, recourse on vehicle owner, etc)? I know machines recycle the gas and oil that they extract, does this mean they pump it into someone else's car or store it to send off for recycling?

Besides flammable, aren't some AC gases carcinogens if they come into contact with a flame or UV?

How do you know what's floating around in any aircon system though? Must be a few people that have read on the net that propane can be used in some aircon systems and tried filling R134 systems with it.