So, first long trip completed and i noticed some real oddness with the LPG filling

The first few times i filled it when the red light came on, but realised it was only taking 45-50L of gas and that the level guage isnt particularly accurate. Pushing it a bit further i got into the 60litre range without issue.

I remembered from the installation certificate that it stated 95L Toroidal tank, and so i expected closer to 70-75L. Imagining 15mpg i guessed 240miles or so should be possible, but thus far i'd stopped way short of that each time due to convenient filling locations.

Once we got down to fareham, I filled the tank, and did about 140miles of driving back and forwards from the hotel and goodwood, lots of heavy traffic etc, and then set off up the motorway and it finally ran out and the gas switched off with 180miles on the dash. Stopped and filled up, and it took 95L?!

I then drove ~200miles up the motorway, and decided it must be needing a fill, but this time it only took 42L?! It worked out an MPG of over 22 so clearly nonsense, i presume it simply didnt fill the tank properly?

Another 200miles up the motorway, stopped again, and this time it took 90L?!

WTF is going on?! For starters a 95L tank should never be taking 90-95L of gas? and why the short fill of 45L?

LPGC or Gilbertd will no doubt drop by with much more insight than I've got, but, from observations over 3 years on the blue car, some LPG fill pumps are weaker than others. My usual Calor centre has a new pump that flies along every time, my fall back retailer's pumps are much slower. In addition I've encountered pumps that steadfastly refused to dispense more than 25p of LPG no matter what I do.
There's an 80% fill limit valve in the system so if yours is filling right to its liquid capacity there's obviously a problem with that valve. Maybe best to stop filling at 75L until you can get it checked.

Pumps do definitely vary but I've never heard of one filling the tank completely full. LPG gauges are all crap in my experience, everyone uses their trip meter instead. 180 miles is about my record for a 70 litre fill, one day I'll get round to taking it back to Simon for a tweak after the new O2 sensors and MAF.

If the fill stop is working correctly the pump should cut off with a very audible clunk, if it just stops pumping, then the stop valve is faulty. If it fills right to the top, again the fill stop is faulty (or the pump is ripping you off).

As said, gauges are very inaccurate, mine stays on 4 lights until I've done 50 miles, drops pretty rapidly until it is showing the red light at around 100-105 miles but I get between 165 miles (towing a 3 tonne trailer) and 230 miles (continuous run at a steady 65-70mph) from a 65-67 litre fill on my 80 litre tank. Average just running around town is 185-190 and on a run at 75-80 mph around 200. I just run until I'm getting close to where I think it is about to run out or until it actually does but as I've got 5 filling stations within 5 miles of me, refilling isn't too much of a problem if I'm at home. On a run I aim to fill up around the 170-190 mile mark to be sure I don't run out.

I filled recently at a Morrisons and the pump seemed very slow and just stopped before it reached the fill stop. I knew it should have taken more than it did and I suspect that was a fault with the pump rather than anything else.

Interesting!

I didnt really notice any clunking, the pump just seemed to stop, so perhaps there is some sort of issue with the tank?

Whats the purpose of stopping short?

The tank should only ever fill to 80% water capacity to allow space for expansion which will be full of vapour anyway. The tank will also have a safety expansion valve on it that will vent if, for example, you fill up to the brim and then leave the car parked in sunlight on a hot day. As 1 litre of liquid Propane will vaporise and form 270 litres of vapour, the cloud from a venting safety valve is pretty impressive and best to be avoided.

There will be a float on an arm inside the tank which operates the shut off valve and you will not miss the clunk when the pump shuts off, if the pump just stops it is because it can no longer supply enough pressure to get any more into the tank. Is it a 4 hole (4 separate bits bolted to the tank to deal with inlet, outlet, etc) or a single hole with a round brass multivalve held in place with a ring of bolts?

My LPG gauge was displaying 2 bars when it was empty. Simon altered the numbers and now it's right.

They can be adjusted but they are never very good, much better to rely on the trip meter. The first LPG car I had was a Saab 900, that showed 3/4 full no matter if it was full, empty or anywhere in between.

Aragorn wrote:

Interesting!

I didnt really notice any clunking, the pump just seemed to stop, so perhaps there is some sort of issue with the tank?

Whats the purpose of stopping short?

I've had 3 cars on lpg (4th is having its kit fitted as time allows at the minute). One of them would make a single clunk when it was full, one barely makes an audible sound on most occasions, the other will make a noise that sounds somewhere like a brick in the washing machine on the spin cycle when it feels like it (usually the same pumps will cause that to happen, other times it will act perfectly normally)

The purpose of stopping short is to allow for expansion space - they are supposed to fill to 80% capacity, The angle of the tank (or the car) can have some effect on this. Your certificate says 95 litre tank, but can you see anything on the actual tank itself (could be wrong cert, tank may have been changed etc).

Its possible that the shut off float arm has been adjusted to allow more by someone previous to yourself.

And no the gauges aren't particularly good, though a new gauge with decent wiring and an adjustable ecu should allow you to set something meaningful up. Two of mine have worked, the 3rd one is a bit random (usually reads full, but sometimes will go right from the red to full over about 10 seconds). I'd replace the level sender if it wasn't corroded in place and ontop of an underslung tank so a pain to access.

I'll have another look at the tank and see if i can see any info on it. Will also have a look and see if its a 4 hole or single hole.

Don't know if has anything to do with it, but on older pumps there was a manometer that showed around 10 bar pressure on delivery.
Today with the digital numbers there is no pressuremeter present anymore, who says it still gives 10 bar pressure?
And does it vary from pump to pump?

Normally the largest tank that will fit in a P38 wheelwell is a 90 litre, 4 hole, filled toroidal so it would be interesting to know what you actually have. I've not known any tank to not shut off with a clunk, I suppose how well soundproofed it is would make a difference to how loud it is. If they don't and the pump just slows down and stops, that normally is a sign that the level stop valve isn't working. Multi tank installations will often 'machine gun' when they are full as the valves will chatter as the pressure between tanks is equalising. I believe you have a Disco Brian and they are often fitted with twin tanks due to the lack of a wheelwell so that might explain why one of yours is noisy.

That tank should have a plate welded to it with the makers name, water capacity (the maximum that will fit in to fill it completely) and date of manufacture. There may be other information on the plate but the only other thing you would be expected to need to know is if it is a 0 or 30 degree tank as that will dictate what multivalve it requires.

Gilbertd wrote:

Normally the largest tank that will fit in a P38 wheelwell is a 90 litre, 4 hole, filled toroidal so it would be interesting to know what you actually have. I've not known any tank to not shut off with a clunk, I suppose how well soundproofed it is would make a difference to how loud it is. If they don't and the pump just slows down and stops, that normally is a sign that the level stop valve isn't working. Multi tank installations will often 'machine gun' when they are full as the valves will chatter as the pressure between tanks is equalising. I believe you have a Disco Brian and they are often fitted with twin tanks due to the lack of a wheelwell so that might explain why one of yours is noisy.

That tank should have a plate welded to it with the makers name, water capacity (the maximum that will fit in to fill it completely) and date of manufacture. There may be other information on the plate but the only other thing you would be expected to need to know is if it is a 0 or 30 degree tank as that will dictate what multivalve it requires.

Your correct in the Disco field, but that tank hasn't been filled up as yet. its the old underslung one on the Galaxy that machine guns. Its going with a big cylinder at the present time in the Disco as the sill tanks just didn't look like they'd have enough capacity. Though I think i should have gone a bit smaller than I did though as the 160 litre cylinder seems somewhat bigger now its in the boot!.

Ferryman wrote:

Don't know if has anything to do with it, but on older pumps there was a manometer that showed around 10 bar pressure on delivery.
Today with the digital numbers there is no pressuremeter present anymore, who says it still gives 10 bar pressure?
And does it vary from pump to pump?

It certainly varies, Still see alot of pumps that have the pressure gauge even the digital ones (theres not much else to notice when you stand there holding the fill button!)

I guess being unfamiliar i'm not really sure if it clunked or not.

From what i remember, the pump stopped fairly abruptly rather than slowing to a trickle. That said, two of us were filling it at various points and it was rather puzzling with the random fill levels that maybe we didnt notice. Or maybe sometimes it did stop properly and other times it didnt.

I guess i'll need to pay closer attention next time i fill it, but its currently about 3/4 full and it'll probably take me a few weeks to do another 150miles or so in it before it needs more gas.

Forgot about finding the plate tonight, i'll try and look tomorrow after work.

Despite being installed by a "pro" theres various stuff about the install that seems pretty shit. The injectors were mounted hanging out over the exhaust manifolds, rather than tucking them in above the rocker covers near the plenum. Various wiring is pretty sketchy looking. The fillers mounted in the plastic bumper with what seems like nothing in the way of reinforcement. There was also no filters anywhere in the installation. I added a vapour filter between the vapouriser and the injectors when i sorted the engine end out.
But its also not worth ploughing huge amounts of cash into trying to fix... I need steering that works and non-shonky brake pipes first!

So i managed to empty the crap out the boot today and have a look at the tank.

It appears to be an ICOM brand, single hole filled toroid, with a plated capacity of 95L.

https://www.dropbox.com/s/zw60bnqarqd31gs/2017-07-08%2015.43.37.jpg?dl=0

https://www.dropbox.com/s/c9ayq4fsduuapl2/2017-07-08%2015.44.04.jpg?dl=0

https://www.dropbox.com/s/tvhobwpodt1bupk/2017-07-08%2015.44.54.jpg?dl=0

This valving arrangement by Icom is unusual on aftermarket conversions but many are fitted on factory converted vehicles.

They're a pain when they go wrong and it seems yours might have gone wrong. If the problem is only at the tank end then it's likely the float is sometimes sticking or the fill shut off sometimes doesn't work. Or one (or both) of those issues could be constant, in which case the reason you don't always get 95L in it would be because you don't always run the tank empty, maybe because of a problem with the under bonnet components.

Obviously something went wrong at the tank end when you managed to get 95L in it, so, perhaps different subject - do you know what parts are fitted under the bonnet?

Simon

I only ran it empty once. Most of the other fills were opportunist fills, as it was convenient or i was stopped anyway etc.

Most of the fills were in the 50-60L range, but ofcourse i didnt know the actual tank level before filling. I got 95L once, which was the only time the gas actually ran out. But then drove something like 190miles and filled it again and only got 45L, so at a guess the first fill brimmed the tank but the second fill stopped properly. The fill after that though did 90L for similar mileage.

At the front end its a Bigas dual reducer and SGIS ECU.

Bigas was a surprise to me, most often where I've seen Icom tanks fitted on aftermarket installs the front end components are a bit unusual too (e.g. AG / Voltran / etc), there's nothing unusual about Bigas.

You'll probably need to change or at least fix the tank valve, would start by looking under the tank's gas tight housing cover to see what type of valve(s) it has, Icom tanks with this type of gas tight housing may have one of a few different types of valve setups. Your type of tank has it's advantages over single hole and 4 hole tanks, I could think of a few applications where they'd be ideally suited but I'd like them more if parts were more easily available.

It is possible to safely fit a normal 95L zero degree (external) tank in the wheel well of a P38. The old way of doing this was to have the valve protrude through the side of the spare wheel well at about 315 degrees (too far North and the anti-roll bar will catch it, too far West and the valve won't reach the tank from the outside of the wheel well due to the squared off bit of well where the jack etc fit)but it's a lot of extra work for the extra few litres the full toroidal external tank offers over the 30 degree internal tank of same measurements because not only does the valve have to go through the side of the well in the correct position but also brackets have to be made to secure the tank from it's top (which is where an external tank's mounting lugs usually all are... there are exceptions, but suppliers don't tend to know which of their external tanks have lugs at both the top and bottom). Internal tanks are secured with a couple of bolts straight through the middle of the boot floor. In case you ever decided to change tanks rather than fix yours, these days it would be possible to fit an external tank upside down in the wheel well using a flexible valve cover, with the tank upside down it's mounting lugs could then be bolted through the well floor saving work making brackets and work fitting the valve, this type of setup would also allow you to keep with much of your existing piping. But an internal 30deg toroidal wlll hold just as much gas if it's valve is bent a bit, is much easier to fit and costs less.

What's the difference between internal and external?

Aragorn wrote:

What's the difference between internal and external?

Valve on an internal is in the centre of the tank (the hole in the donut shape). External is on the outside edge. At least i think thats what Simon is getting at?