Ping Austin Shackles/Badger

Hi Guys, OT I know on here but I have just had a 3.2 XJ jag converted on a
closed loop single point system (OMVL) system runs fine apart from sometimes
when decelerating , especially braking quite sharply into a corner for
example the revs die to a couple of hundred and then when the loud pedal is
pressed the car lurches forward as it comes back on song.

I am obviously going to take it back but just wanted to have some arrows to
shoot at them, always good to look as if you know what you are on about

PS my fuel computer is still working showing instantaneous MPG average MPG
etc - is this valid, i.e. is it reading on LPG ?

Also the 61L tank only took around 34 L to fill today ( first fill) the guy
told me it would take three or four fills to reach max capacity - is this
true? and if so why?

Thanks in advance gents,

A non Landy lurker !!!

Steve

On or around Mon, 1 Aug 2005 18:59:23 +0100, "StaffBull"
<[email protected]> enlightened us thusly:

>Hi Guys, OT I know on here but I have just had a 3.2 XJ jag converted on a
>closed loop single point system (OMVL) system runs fine apart from sometimes
>when decelerating , especially braking quite sharply into a corner for
>example the revs die to a couple of hundred and then when the loud pedal is
>pressed the car lurches forward as it comes back on song.

Could be vaporiser orientation - if the vap. is mounted facing fore-and-aft.
The face where the pipes attach should normally point across the vehicle,
not forwards or backwards.

other possibility is incorrect tuning - the OMVL 90E has a fixed bleed which
allows a small amount of gas through all the time the vlaves are open
(system live) and one of the functions of this is to reduce the chance of
stalling on deceleration, but I think it's more about when you lift off
coming to a standstill.

> I am obviously going to take it back but just wanted to have some arrows to
>shoot at them, always good to look as if you know what you are on about
>
> PS my fuel computer is still working showing instantaneous MPG average MPG
>etc - is this valid, i.e. is it reading on LPG ?

depends on how it meters. Some of them work on the airflow, and thus still
read but may not be accurate.
>
> Also the 61L tank only took around 34 L to fill today ( first fill) the guy
>told me it would take three or four fills to reach max capacity - is this
>true? and if so why?

if the tank's been properly installed, that shouldn't be so. Was it empty
when you filled it?

if it's a 61L water capacity tank, then it'll hold about 48-49L of LPG in
normal use with an 80% fill valve.

Normally, reduced capacity is either that the tank orientation is wrong,
incorrect float valve in the tank, or tank incorectly/not purged of air at
fitting.

properly, you put a small amount of liquid gas in, invert the tank and open
the outlet valve, to get the air and/or inert gas from the tank. Once
purged thus, the vapour space in the tank will contian mostly LPG. If the
tank was full of air at atmopspheric pressure when installed, and not
purged, then this air (61L) will compress to about 7-8 bar (normal pressure
in a part-full propane tank which will occupy about 8L of your volume - not
enough to upset things. If the tank happened to be filled with air at 2
bar, then when it's compressed to 7-8 bar it'll occupy about 16L, which is
borderline - the compressed air, if too much, will cause overpressure in the
tank, and since most pumps have a pressure shut-off, you may not get a full
fill.

--
Austin Shackles. www.ddol-las.net my opinions are just that
"Pereant qui ante nos nostra dixerunt"
(confound the men who have made our remarks before us.)
Aelius Donatus (4th Cent.) [St. Jerome, Commentary on Ecclesiastes]

Hi Austin, the vap appears to be positioned correctly - I will post up some
pics tomorrow and send you a link - if you would cast your peepers on em I
would appreciate it. On looking at the system now, if I put my nose to the
vap I can smell LPG, the car was last run 2 hours ago - I cant seem to
remember that on my Disco - I'd sometimes get a whiff but that was only even
on start-up. Is this normal?

I was hoping this was going to be as reliable as my Disco, but I'm a little
wary now!! just paid £1100 for it, you don't expect it to play up first 50
miles!! or are there teething troubles with new set ups?

Cheers, Steve


"Austin Shackles" <[email protected]> wrote in message
news[email protected]...
> On or around Mon, 1 Aug 2005 18:59:23 +0100, "StaffBull"
> <[email protected]> enlightened us thusly:
>
>>Hi Guys, OT I know on here but I have just had a 3.2 XJ jag converted on a
>>closed loop single point system (OMVL) system runs fine apart from
>>sometimes
>>when decelerating , especially braking quite sharply into a corner for
>>example the revs die to a couple of hundred and then when the loud pedal
>>is
>>pressed the car lurches forward as it comes back on song.
>
> Could be vaporiser orientation - if the vap. is mounted facing
> fore-and-aft.
> The face where the pipes attach should normally point across the vehicle,
> not forwards or backwards.
>
> other possibility is incorrect tuning - the OMVL 90E has a fixed bleed
> which
> allows a small amount of gas through all the time the vlaves are open
> (system live) and one of the functions of this is to reduce the chance of
> stalling on deceleration, but I think it's more about when you lift off
> coming to a standstill.
>
>> I am obviously going to take it back but just wanted to have some arrows
>> to
>>shoot at them, always good to look as if you know what you are on about
>>
>>
>> PS my fuel computer is still working showing instantaneous MPG average
>> MPG
>>etc - is this valid, i.e. is it reading on LPG ?
>
> depends on how it meters. Some of them work on the airflow, and thus
> still
> read but may not be accurate.
>>
>> Also the 61L tank only took around 34 L to fill today ( first fill) the
>> guy
>>told me it would take three or four fills to reach max capacity - is this
>>true? and if so why?
>
> if the tank's been properly installed, that shouldn't be so. Was it empty
> when you filled it?
>
> if it's a 61L water capacity tank, then it'll hold about 48-49L of LPG in
> normal use with an 80% fill valve.
>
> Normally, reduced capacity is either that the tank orientation is wrong,
> incorrect float valve in the tank, or tank incorectly/not purged of air at
> fitting.
>
> properly, you put a small amount of liquid gas in, invert the tank and
> open
> the outlet valve, to get the air and/or inert gas from the tank. Once
> purged thus, the vapour space in the tank will contian mostly LPG. If the
> tank was full of air at atmopspheric pressure when installed, and not
> purged, then this air (61L) will compress to about 7-8 bar (normal
> pressure
> in a part-full propane tank which will occupy about 8L of your volume -
> not
> enough to upset things. If the tank happened to be filled with air at 2
> bar, then when it's compressed to 7-8 bar it'll occupy about 16L, which is
> borderline - the compressed air, if too much, will cause overpressure in
> the
> tank, and since most pumps have a pressure shut-off, you may not get a
> full
> fill.
>
> --
> Austin Shackles. www.ddol-las.net my opinions are just that
> "Pereant qui ante nos nostra dixerunt"
> (confound the men who have made our remarks before us.)
> Aelius Donatus (4th Cent.) [St. Jerome, Commentary on Ecclesiastes]

Hi Austin, called em today and its booked in on Sat, the guy told me that
the tank had not been purged, but will evacuate the air in subsequent
fillings !! now I cant see how, surely the air is trapped in the top portion
of the tank due to the liquid gas at the bottom, being a liquid take off at
the bottom of the tank the air cant escape. Am I right? I don't want to make
a T1T out of myself by arguing the toss on Saturday.

Cheers, - i have also found out they have not adjusted the timing on the
car - I thought this needed to be adjusted for running LPG?

Ta once again,

Steve

"Austin Shackles" <[email protected]> wrote in message
news[email protected]...
> On or around Mon, 1 Aug 2005 18:59:23 +0100, "StaffBull"
> <[email protected]> enlightened us thusly:
>
>>Hi Guys, OT I know on here but I have just had a 3.2 XJ jag converted on a
>>closed loop single point system (OMVL) system runs fine apart from
>>sometimes
>>when decelerating , especially braking quite sharply into a corner for
>>example the revs die to a couple of hundred and then when the loud pedal
>>is
>>pressed the car lurches forward as it comes back on song.
>
> Could be vaporiser orientation - if the vap. is mounted facing
> fore-and-aft.
> The face where the pipes attach should normally point across the vehicle,
> not forwards or backwards.
>
> other possibility is incorrect tuning - the OMVL 90E has a fixed bleed
> which
> allows a small amount of gas through all the time the vlaves are open
> (system live) and one of the functions of this is to reduce the chance of
> stalling on deceleration, but I think it's more about when you lift off
> coming to a standstill.
>
>> I am obviously going to take it back but just wanted to have some arrows
>> to
>>shoot at them, always good to look as if you know what you are on about
>>
>>
>> PS my fuel computer is still working showing instantaneous MPG average
>> MPG
>>etc - is this valid, i.e. is it reading on LPG ?
>
> depends on how it meters. Some of them work on the airflow, and thus
> still
> read but may not be accurate.
>>
>> Also the 61L tank only took around 34 L to fill today ( first fill) the
>> guy
>>told me it would take three or four fills to reach max capacity - is this
>>true? and if so why?
>
> if the tank's been properly installed, that shouldn't be so. Was it empty
> when you filled it?
>
> if it's a 61L water capacity tank, then it'll hold about 48-49L of LPG in
> normal use with an 80% fill valve.
>
> Normally, reduced capacity is either that the tank orientation is wrong,
> incorrect float valve in the tank, or tank incorectly/not purged of air at
> fitting.
>
> properly, you put a small amount of liquid gas in, invert the tank and
> open
> the outlet valve, to get the air and/or inert gas from the tank. Once
> purged thus, the vapour space in the tank will contian mostly LPG. If the
> tank was full of air at atmopspheric pressure when installed, and not
> purged, then this air (61L) will compress to about 7-8 bar (normal
> pressure
> in a part-full propane tank which will occupy about 8L of your volume -
> not
> enough to upset things. If the tank happened to be filled with air at 2
> bar, then when it's compressed to 7-8 bar it'll occupy about 16L, which is
> borderline - the compressed air, if too much, will cause overpressure in
> the
> tank, and since most pumps have a pressure shut-off, you may not get a
> full
> fill.
>
> --
> Austin Shackles. www.ddol-las.net my opinions are just that
> "Pereant qui ante nos nostra dixerunt"
> (confound the men who have made our remarks before us.)
> Aelius Donatus (4th Cent.) [St. Jerome, Commentary on Ecclesiastes]

On or around Tue, 2 Aug 2005 18:35:00 +0100, "StaffBull"
<[email protected]> enlightened us thusly:

>
> Hi Austin, called em today and its booked in on Sat, the guy told me that
>the tank had not been purged, but will evacuate the air in subsequent
>fillings !! now I cant see how, surely the air is trapped in the top portion
>of the tank due to the liquid gas at the bottom, being a liquid take off at
>the bottom of the tank the air cant escape. Am I right? I don't want to make
>a T1T out of myself by arguing the toss on Saturday.

hehe. well... hard to say. depends on how much air. You can get it down
to atmospheric pressure if necessary by running on gas 'til it runs out,
then go to the top of a big hill, and switch back to the empty gas tank,
then run downhill in gear with the ignition on. This will keep the valves
open and allow the pressure to get out of the tank. Air at atmospheric
pressure should not give trouble. Apart from that, you're right, the air
can't get out of a bottom-outlet tank with liquid in it. But see above -
when you run out of gas, your liquid level will probably drop below the
outlet level now and again.

> Cheers, - i have also found out they have not adjusted the timing on the
>car - I thought this needed to be adjusted for running LPG?
>

ah, well, now you're getting to the complicated bit. LPG runs better with
more initial advance and less high-speed advance, in other words, with a
different advance curve. To make that happen requires an ignition processor
which costs extra. You can do a cheaper option which is to advance the
spark timing about 3 degrees from the 4* setting or about 6 degrees from
unleaded setting. This will make the gas run a bit better and shouldn't
compromise the petrol running too much. Check it doesn't pink too much on
petrol though.

--
Austin Shackles. www.ddol-las.net my opinions are just that
"Any man's death diminishes me, because I am involved in Mankind; and
therefore never send to know for whom the bell tolls, it tolls for thee"
John Donne (1571? - 1631) Devotions, XVII

"StaffBull" <[email protected]> wrote in message
news:[email protected]...
> Hi Guys, OT I know on here but I have just had a 3.2 XJ jag converted on a
> closed loop single point system (OMVL) system runs fine apart from
> sometimes when decelerating , especially braking quite sharply into a
> corner for example the revs die to a couple of hundred and then when the
> loud pedal is pressed the car lurches forward as it comes back on song.
>
> I am obviously going to take it back but just wanted to have some arrows
> to shoot at them, always good to look as if you know what you are on about
>
>
> PS my fuel computer is still working showing instantaneous MPG average
> MPG etc - is this valid, i.e. is it reading on LPG ?
>
> Also the 61L tank only took around 34 L to fill today ( first fill) the
> guy told me it would take three or four fills to reach max capacity - is
> this true? and if so why?

Sorry for delay in replying, just back from holiday. I think from what I've
read that Austin & co have pretty much suggested all that I would look for
initially myself. Moving on, what OMVL system is it, is it the Millenium? If
so, get it on the computer, clamp the "idle closing steps below default" to
5 and adjust the vapouriser idle bleed to a point where it can only just
cycle rich-lean, remaining rich for longer than lean (bear in mind these
rich and lean values are only just off perfect mixture, we're not talking
drastic mixture changes here) and going rich almost as soon as the stepper
motor starts to open towards default, checked by selecting the default lock
option and selecting "idle opening steps above default" to zero and
monitoring the lambda readout on the computer, then put it back to 25 steps,
so that the system has the scope to cope with increased loadings on the
engine. Also check if the fuel overrun cut-off option has been selected, if
so it may be cutting off too much fuel, or not reinstating fuel until too
low an rpm threshhold.
Good luck.
Badger.

Cheers, it is indeed a Millennium system, I will ask them to follow your
instructions

Very much appreciated,

Thanks once again,

Steve


"Badger" <[email protected]> wrote in message
news:[email protected]...
>
> "StaffBull" <[email protected]> wrote in message
> news:[email protected]...
>> Hi Guys, OT I know on here but I have just had a 3.2 XJ jag converted on
>> a closed loop single point system (OMVL) system runs fine apart from
>> sometimes when decelerating , especially braking quite sharply into a
>> corner for example the revs die to a couple of hundred and then when the
>> loud pedal is pressed the car lurches forward as it comes back on song.
>>
>> I am obviously going to take it back but just wanted to have some arrows
>> to shoot at them, always good to look as if you know what you are on
>> about
>>
>> PS my fuel computer is still working showing instantaneous MPG average
>> MPG etc - is this valid, i.e. is it reading on LPG ?
>>
>> Also the 61L tank only took around 34 L to fill today ( first fill) the
>> guy told me it would take three or four fills to reach max capacity - is
>> this true? and if so why?
>
> Sorry for delay in replying, just back from holiday. I think from what
> I've read that Austin & co have pretty much suggested all that I would
> look for initially myself. Moving on, what OMVL system is it, is it the
> Millenium? If so, get it on the computer, clamp the "idle closing steps
> below default" to 5 and adjust the vapouriser idle bleed to a point where
> it can only just cycle rich-lean, remaining rich for longer than lean
> (bear in mind these rich and lean values are only just off perfect
> mixture, we're not talking drastic mixture changes here) and going rich
> almost as soon as the stepper motor starts to open towards default,
> checked by selecting the default lock option and selecting "idle opening
> steps above default" to zero and monitoring the lambda readout on the
> computer, then put it back to 25 steps, so that the system has the scope
> to cope with increased loadings on the engine. Also check if the fuel
> overrun cut-off option has been selected, if so it may be cutting off too
> much fuel, or not reinstating fuel until too low an rpm threshhold.
> Good luck.
> Badger.
>