BXProject

[mat_the_cat]

I've already mentioned this in my whinge (sorry blog) over on BXC but thought I would have a moan over here too and maybe get some useful advice.

Had a problem with the Discovery over the last few weeks - loss of coolant, rock hard hoses, bubbles in the expansion tank and rough running on gas. Failed HG you might think, but a compression test showed extremely good figures on all 8 cylinders. So then I stripped down the stepper motors allowing gas to be 'injected' into the inlet manifold (1 per bank, each feeding 4 ports) to find there was a significant amount of water in them! So I deduced the problem must lie in the vaporiser which is heatered by the coolant and supplies a constant pressure of vaporised LPG to each stepper motor. I managed to find a rebuild kit for the vaporiser and fully rebuilt it. Result! It ran much better, no pressurisation and more top end power. The slight roughness at idle was still there, I think as a result of me changing one of the stepper motors a few months ago - when they are installed as pairs they should be a balanced pair from the factory as at idle when they are both nearly closed any slight differences in flow are magnified. Open the throttle and it's nice and smooth so I wasn't too fussed. But I thought I would take it to the local specialist (70 miles away!) as we were heading in that direction anyway and were planning to do a lot of towing over Christmas so wanted to ensure things were A1.

They did make it clear to me that they couldn't promise an improvement, and that they would recommend removing the system to fit one of theirs instead. This I declined as it would cost significantly more than an hour of their diagnostic time, so they said that they would do the best they could. All I requested them to do was check that any stepper motor imbalance wasn't causing one bank of the V to run dangerously lean, and to try and increase the idle speed a touch to smooth the idle.

So by the time they finished with the car they tell me they've tried various different maps, and also altered the speed of the self learning setting, but all this made things worse. So my original map was put back in, and it just needed a run on the open road to re-learn parameters for some fine tuning (they were unable to do this due to Christmas traffic).

This I tried, but switching to gas on the move (as advised) many times for about 20 miles just left me coasting with no power. Pulling into a layby we found that it will idle (just) on gas but will not rev above 1500rpm and would backfire if the throttle was pressed further. Upon phoning them back they told me that there was nothing more they could do without substituting parts (which they didn't have) as the gas pressure was too low. But surely if there was an inherent problem with the gas pressure it wouldn't have run satisfactorily for the 100 or so miles after the vaporiser rebuild before I took it in.

I can’t believe I’ve paid money to end up with an LPG system going from working reasonably well, to being useless. It is obviously possible that an unrelated problem occurred whilst in their position, but I’m shafted really. Economically I can’t take it back there for them to try various new parts at my expense without any guarantee of success. I don’t really know what the legal position is - I just want it in the same usable condition it was in before I took it in to the specialist, without being (further) out of pocket.

I discovered that by repeatedly pumping the throttle it was possible to get the revs over 3k rpm, at which point it would rev perfectly normally and hold a steady engine speed from 3k upwards. Drop (even slightly) below 3k though, and the revs would rapidly drop to around 1500 and become rougher. It was possible (just) to drive the car but only below about 10mph as there was no power.

After getting the Disco back home I spotted a split vacuum hose from the inlet manifold to the vaporiser. I think the inlet manifold vacuum moves a diaphragm and allows more LPG into the vaporiser. The hose I know wasn’t split to start with as I reconnected it when I put the rebuilt vaporiser back in - I remember it being a tight fit of the stub it pushed onto which is where it had split.

I initially thought that this would lead to a buggering up of the self learning program, and a simple reset of this would enable it to relearn OK. But now I've found out the self learning is continuous, so whatever fault is present must still be there. The LPG specialist has told me they have no base maps (from which the self learning fine tunes) for the Rover V8 so fuck knows what they have actually programmed it with.

Found another specialist who were the importers for that equipment when it was current (they no longer import that make) so should know what they are on about. Problem is they want the vehicle for several days which is an issue, and fault finding would run into many hours...

Just had an increase on my credit card limit so feel like just throwing money at the problem to make it go away. Even if it comes to a new system, at least then it will (should?) be more reliable, and have better spares availability in the future. I've had some fundamental problems with the system installation pointed out to me (some I knew about like the wiring quality) so maybe that's the best option?

I'm considering giving the second specialist a fixed budget of X hours, so if it isn't a simple fix I won't run into a bill of hundreds of pounds that would be better spent on a new system. One possible thought that springs to mind is that if they adjusted the vaporiser to try and change the gas pressure with a leaking vacuum pipe, the pressure will now be all to cock, and it could just be a simple tweak on a screw?

Oh, and today there was a bang and hiss from the underneath, with a strong smell of gas. Tank contents still OK, so must have been the residual pressure in the pipe leading from the filler port to the tanks. Should be cheap and easy to replace.

[Bx Bandit]

Blimey, I've read all of that and still have no understanding of the gas system! Honestly Matt, it's not you, it's me and my lazy brain.

Skipping heavy detail, and maybe missing the point...........

1) replace split hose and go from there (I know you would of thought of this but I'm missing something I'm sure)
2) If you are friendly with the garage who worked on your car, don't alienate them with verbal etc. Work with them, and get their sympathy. Doubtful you'll get summat for nowt but you may get a good result for not a lot of tokens.
3) Weigh up the short to mid term cost of getting the gas system fixed versus current (and don't forget soon-to-be-increased) petrol costs
4) 'Black box' it to a known good gas specialist and pay for it to be sorted. Over a year it may not prove to be more than (3) above and so after that you're quids in.
5) sell the fucker and get a diesel

[mat_the_cat]

Don't worry mate, I'm probably not explaining things very well as I'm not exactly an expert either!

1) Have replaced split hose - I initially thought the self learning finished after a set period, so a simple reset with the leak plugged might have sorted it. But it should self learn continually so the fact it's no better wit the pipe replaced suggests more wrong.
2) Not friendly with them, but not been rude either. It still may be an unlucky coincidence, so they may yet sort it once I point out to them about the split pipe.
3 & 4) Exactly what I'm doing! It was a good system when working, but spares availability not great now and a bugger to diagnose I'm told. Versus a new front end to the system (keeping the tanks which are a significant cost) which would come with a warranty and hopefully longer term reliability and spares availability. LPG systems have moved on massively in recent years - they used to have to be mapped to suit the particular engine they were fitted too (usually using only the basic sensors - TPS/lambda/MAP), which is always going to be a more compromised map than the vehicle manufacturer can create with all their R&D budget/experience with the engine when creating the petrol map. Modern ones intercept the petrol injector timings, and simply modify those to suit the different burn characteristics of LPG and a correction factor for the LPG and ambient pressures. So you get the benefit of the vehicle manufacturer's ECU using all the engine's sensors, doing the work, and the gas ECU piggybacking on top of it.
5) Diesel? You'd be looking at an extra 1k plus over an equivalent petrol model, we have the spares for the petrol, the V8 on LPG is cheaper to run (excluding repairs!), has more power and sounds better! Nuff said...

[jayw]

Don't know if it's of any help Mat but a few years ago i had a Rover 820 which had the same "self-learning" type EMS.

It developed a problem with running like a bag 'o' spanners which would improve the longer it was driven. Turning the engine off would cause it to revert to aforementioned bag 'o' spanners mode...

Couldn't find the cause and as the MOT was nearing (and the emissions were shot to buggery) i put it into the Rover main stealer. Using the Rover "TestBook" (their diagnostics) they could set it all up just fine but whenever they turned the car off it would still reset.

After 4 hours labour they gave up, suggesting that the permanent live-feed to the ECU (which keeps it's memory) wasn't working.

Took it to an auto electrician who fixed the feed within an hour.

My shopping around at the time did quite clearly show that ONLY the "Rover TestBook" could be used to program their range... whether that's changed or not i don't know.

Of course, whether ANY of that can relate to the LPG problem is unknown

[mat_the_cat]

Well it's worth knowing, but don't think it relates to this problem as the gas ECU stores everything it's learnt in EEPROM. I've taken it out of the car when doing welding (after the last time!) and it's remembered OK.

I wish I had the software to communicate - I've even managed to acquire the installer only access log in to the BRC (LPG kit manufacturers) website but the software for the system I have is no longer available to download.

I guess this thread is less of a request for answers (although ideas always welcome!) and more of a 'kicking myself for taking a working system into a garage and having them make it useless' kind of thread...

And it's not a moan at the car itself, these things can happen at any time running an older car. In fact been very happy with it, went through the MOT with only one advisory on brake pipes and it was the only thing that got out of our drive in the snow! (Even rescued a guy who was stuck and towed him up the hill, was most surprised when he thrust a tenner into my hands - mind you it was on petrol at the time so probably barely covered the fuel costs...)

[Philhod]

Well, I`m afraid I hanen`t worked on any of these, but I have worked on large oil to gas converters. These were relatively trouble free, however, the only place they gave problems was in Canada, where (significantly) very low temperatures caused very noticeable drops in output gas pressure. Melting ice also caused water inclusion.
The (then very new) electronic control systems again gave trouble under the very cold conditions.
Dont know if it`s any of use...................................

[mat_the_cat]

Your post has made my day Phil!

Well, I`m afraid I hanen`t worked on any of these

Finally found something you haven't worked on...

[Philhod]

Finally found something you haven't worked on...

I know it doesn`t happen often.... just occasionally

[mickey taker]

ok , this is my tuppence worth,

Matt what you have said is the reason I gave up looking for an lpg car,

apart from the cherokee I " bought" on ebay running like a bag of nails on gas despite the fact the whole front end of the conversion having been replaced at a cost of some £700 ( hence me walking away from it )

most of the cars I saw had issues either running on gas or possible head gasket problems.


then you get the situaition your in where a system is no longer available so spares cant be had. and yes you can reuse the tanks but have to find the cost of a new system.

therefore all these savings you are supposed to make running on lpg can disappear in an instant.

One day lpg may be a viable alternative but so far there seem to be more issues than benefits over the long term.

[mat_the_cat]

I'm inclined to at least partly agree with you there. I know it can work well, but equally there can be problems (I don't know enough to say whether the problems affect a significant proportion of the converted cars, or just get the bad press because bad news travels better).

When we bought it the only way to tell it was running on gas was by looking at the switch, which I believe is the way it should be. Part of the problems I think stem from people going for the cheapest kits (understandably as a quicker payback time, and a lot of suspect 'advice' out there). Others from poor quality installations, as the professionals self certify their own work and the longer they take over a job, they less profit they make.

My experience of installers/manufacturers suggests they have a limited captive market, and take full advantage of that. Hence a simple fault can allegedly require a new front end as that is the more profitable option for the installer (and with more guarantee of success), rather than fault finding on a possibly unfamiliar system. And the average bloke in the street isn't going to disagree, particularly if safety is called into question!

The last point you make I think would make real sense if LPG was incorporated at the vehicle/engine design stage, rather than a generic add on that has to be tailored to suit the vehicle. Personally I'm still for it, but it's not a miracle solution. And the worry is the duty will go up, wiping out the big savings. Despite the fact it's much cleaner - the last Disco would pass the cat MOT with the catalysts removed, so why isn't there more of a push with all the emphasis on the environment?

[jayw]

why isn't there more of a push with all the emphasis on the environment?

Simples. In the REAL world no-one gives a fuck about the environment, it's ALL about money. Most "environmental" issues are just moneyspinners for someone somewhere...

Very petty, but the best example i ever found of this was Polystyrene packaging... resource intensive to make, creates a shit load of greenhouse gasses during production, doesn't biodegrade EVER and accounts for 5% of waste in landfill after 50 years. But, it's BIG business and there's nothing else like it so why bother changing it.

Environment... Meh!

[mickey taker]

I feel the same about catalytic convertors and lamba sensors,



just someones idea to make loads of money, production pollution probably far outweighs any saving to the enviroment

[Vanny]

i've got a working eeprommer if you need to borrow it. Maybe if you can find a working map you can back it up?

[Stinkwheel(Matt)]

I feel the same about catalytic convertors and lamba sensors,

just someones idea to make loads of money, production pollution probably far outweighs any saving to the enviroment

See, i agree with that. Basically no mater how much we clean up motoring, its just industry and manufacturing and jet flight that really cause the problems. otoring is a real drop in the ocean. Eliminate those things, virtually eliminate global warming, carbon footprint and any other media phrases related.

I realise we all know this, just fancied a quick rant.

[Vanny]

virtually eliminate global warming

Hows that then? It's a naturally occurring phenomena that has happened 16 times since the earth was formed. Trying to eliminate it is like trying to stop time its self.

[Philhod]

Totally agree Vanny. Global warming (and cooling) happens in cycles and has actually happend on many occasions (on a smaller scale than ice ages I mean) and will continue to do, wether we pay millions out for the con or not

[mat_the_cat]

I think what Matt was meaning that we could massively reduce the impact of humans on the cycle (if indeed there is one?) without hammering the motorist...

Cheers for the offer of the programmer Vanny, although I'd have no clue how to communicate with the EEPROM without the official software. Made a TTL to RS232 converter though , which no longer works

If and when we get a proper map we will definitely request a backup though!

[Vanny]

level shifter, MAX232 i suppose, i went through a period of building two a week over the summer because people kept loosing them.

To read in the eeprom, you just have to tell the eeprom to load a buffer, read it in, clear it and do the next block, its very very very simple to read them. Decoding the contents however is a little trickier. If you can figure out what the processor is then you can figure out what the instruction format should be, identify basic codes and work out where the various data tables are. All reasonably striaght forward, but very labourious and mind numbing work.

Collectively the human race since it's beginning have probably only advanced the arrival of the next ice age by at most a couple of years, and compared to the 10,000year or so cycle that they turn up on, we haven't made one bleeding jot of difference.

Also, the human race has an impact on global warming that has been declining for years. The only reason anyone uses it as a poking stick is because of a couple of news papers picking up on it an running.

However i don't agree for one second with the planet of greed that has been created. Personally i've been taking stuff to the recycling bin at tesco's (remember them) for as long as i can remember, not because i thought i would save the earth (back then it all went in land fill and i knew it) but because renewing, recycling and reusing is the basis of decent society. Waste and greed are not!

Oooh its gone all serious.

[Father Ted]

Cut air travel - I like it.
Nuclear powered ocean going liners, now theres a thought....

I mean come on, OK so you can get to America in a few hours, but you spend days feeling like shit. Take a boat and chill. then enjoy your break and you can feel refreshed.
Admittedly this type of attitude will need a radical rethink of how we holiday - so I propose a nationwide shutdown of all inductry excepting the emergency services for 4 weeks every summer and 4 weeks every winter. This will mean the abolition of bank holidays and silly sunday trading laws and an adoption of continental trading times to enable people to get shopping and shit like that done.

I mean, in these days of t'interweb is there as much need to travel?

No. Then ban air travel for holidays.

[Philhod]

I would sooner fly from Manchester to Köpenhamn in winter, than drive in the car. Fine in the summer though.
For some of us it isn`t just a holiday, more keeping in touch with family

You obviously haven`t been at sea in a force 9 or above FT. Even in big ships the movement is err rather unpleasant