I installed an LPG kit in a citroen AX (well I actually took a lot of the
components
from my previous car which expired). The citroen has a carb and I have tuned
the vapouriser and flow value with an exhaust gas analyser.

The car starts and runs fine from warm. I notice the engine needs a few more
revolutions to start than petrol. However from cold the engine shows no
willingness
to start on lpg. I have increased the time that lpg is supplied to the
engine when starting
and this allows it to burst into life a little then it dies.

Since the car has a mechanical petrol fuel pump it can take a long time
cranking
to get it to fire if I forget to switch back to petrol before the last run
of the day.

Any advice here or should I just stick to finishing on petrol for the night?

On or around Sun, 9 Nov 2003 21:56:23 -0000, "David Cawkwell"
enlightened us thusly:

I installed an LPG kit in a citroen AX (well I actually took a lot of the
components
from my previous car which expired). The citroen has a carb and I have tuned
the vapouriser and flow value with an exhaust gas analyser.

The car starts and runs fine from warm. I notice the engine needs a few more
revolutions to start than petrol. However from cold the engine shows no
willingness
to start on lpg. I have increased the time that lpg is supplied to the
engine when starting
and this allows it to burst into life a little then it dies.

Since the car has a mechanical petrol fuel pump it can take a long time
cranking
to get it to fire if I forget to switch back to petrol before the last run
of the day.

Any advice here or should I just stick to finishing on petrol for the night?


what figures did you tune the LPG to? Mixture is fairly critical. If it's
too lean, it'll not start readily from cold, if too rich, it'll "flood".
get it right, it should work... You may need to play with vapouriser idel
settings, depending on what yer vapouriser is.


--
Austin Shackles. www.ddol-las.fsnet.co.uk my opinions are just that
01234567891123456789212345678931234567894123456789 51234567896123456789712345
1 weebl: What's this? | in recognition of the fun that is weebl and bob
2 bob: it a SigRuler! | check out the weebl and bob archive:
3 weebl: How Handy! | http://www.weebl.jolt.co.uk/archives.php

At idle I was getting about 1 to 1.2 % co2. Reducing to 0.5-0.6 ish when
running
the engine at 2-3000. rpm.

I'm a bit uncertain here due to the fact I've had conflicting quotes on what
to tune the co2 to for LPG.

What C02 do you suggest?


"Austin Shackles" wrote in message
...
On or around Sun, 9 Nov 2003 21:56:23 -0000, "David Cawkwell"
enlightened us thusly:

I installed an LPG kit in a citroen AX (well I actually took a lot of the
components
from my previous car which expired). The citroen has a carb and I have
tuned
the vapouriser and flow value with an exhaust gas analyser.

The car starts and runs fine from warm. I notice the engine needs a few
more
revolutions to start than petrol. However from cold the engine shows no
willingness
to start on lpg. I have increased the time that lpg is supplied to the
engine when starting
and this allows it to burst into life a little then it dies.

Since the car has a mechanical petrol fuel pump it can take a long time
cranking
to get it to fire if I forget to switch back to petrol before the last
run
of the day.

Any advice here or should I just stick to finishing on petrol for the
night?


what figures did you tune the LPG to? Mixture is fairly critical. If
it's
too lean, it'll not start readily from cold, if too rich, it'll "flood".
get it right, it should work... You may need to play with vapouriser idel
settings, depending on what yer vapouriser is.


--
Austin Shackles. www.ddol-las.fsnet.co.uk my opinions are just that

01234567891123456789212345678931234567894123456789 51234567896123456789712345
1 weebl: What's this? | in recognition of the fun that is weebl and bob
2 bob: it a SigRuler! | check out the weebl and bob archive:
3 weebl: How Handy! | http://www.weebl.jolt.co.uk/archives.php

On or around Mon, 10 Nov 2003 20:08:25 -0000, "David Cawkwell"
enlightened us thusly:

At idle I was getting about 1 to 1.2 % co2. Reducing to 0.5-0.6 ish when
running
the engine at 2-3000. rpm.

I'm a bit uncertain here due to the fact I've had conflicting quotes on what
to tune the co2 to for LPG.

What C02 do you suggest?

I assume you mean CO. 0.5-0.6 shouldn't be far out. You might want it a
touch richer (i.e. higher CO figure) at 3000, but it shouldn't be far off.
Try it a tad richer and see what happens.

if it's a bit rich, you get the thing where it fires initially and then
conks again - if you have a switch with an "off" position, you can try
turning it off while cranking, and see if it fires again. They mostly seem
to need a bit more throttle and a bit more cranking than a petrol carb.

--
Austin Shackles. www.ddol-las.fsnet.co.uk my opinions are just that
01234567891123456789212345678931234567894123456789 51234567896123456789712345
1 weebl: What's this? | in recognition of the fun that is weebl and bob
2 bob: it a SigRuler! | check out the weebl and bob archive:
3 weebl: How Handy! | http://www.weebl.jolt.co.uk/archives.php

Yes CO my chemistry was never up to much.

I'll try it richer and see what I get.

"Austin Shackles" wrote in message
...
On or around Mon, 10 Nov 2003 20:08:25 -0000, "David Cawkwell"
enlightened us thusly:

At idle I was getting about 1 to 1.2 % co2. Reducing to 0.5-0.6 ish when
running
the engine at 2-3000. rpm.

I'm a bit uncertain here due to the fact I've had conflicting quotes on
what
to tune the co2 to for LPG.

What C02 do you suggest?

I assume you mean CO. 0.5-0.6 shouldn't be far out. You might want it a
touch richer (i.e. higher CO figure) at 3000, but it shouldn't be far off.
Try it a tad richer and see what happens.

if it's a bit rich, you get the thing where it fires initially and then
conks again - if you have a switch with an "off" position, you can try
turning it off while cranking, and see if it fires again. They mostly
seem
to need a bit more throttle and a bit more cranking than a petrol carb.

--
Austin Shackles. www.ddol-las.fsnet.co.uk my opinions are just that

01234567891123456789212345678931234567894123456789 51234567896123456789712345
1 weebl: What's this? | in recognition of the fun that is weebl and bob
2 bob: it a SigRuler! | check out the weebl and bob archive:
3 weebl: How Handy! | http://www.weebl.jolt.co.uk/archives.php