VY with problems on LPG

[Timmos]

Had my car looked at today by a couple of places, and none of them could figure out why my LPG would run fine on IDLE yet stall on throttle. The first place i went to adjusted the LPG to max which didn't fix anything.

One place suggested the converter could be "contaminated", which would need replacing. pricing upwards of $400, as much as i'd love to get my LPG working i cannot justify spending another $400 to save a few $ on fuel.

I have a duel-fuel Impco gas system and its only done 30,000kms since install (03/09) I've been told if it is the converter, it would not be under warranty. Out of those 30,000kms i've probably only ran it on gas for 10,000kms

Any suggestions what i should do?

 

[strgas]

check your warranty on the installed system and take it back to the installer

 

[sleepa]

On my system there are 2 screws on the converter, 1 for idle and 1 for when it runs. On yours it sounds like the idle is set up alright but the other one may need adjusting. I also have a max power adjustment screw in the pipe to the intake. Are you sure he adjusted the right screw? and the right way? Also mine doesn't run on too little or too much gas, it needs the right mixture.

 

[Timmos]

Yeah the installers were the ones that told me it wouldn't be covered.

I have noticed those 2 adjustable screws but never been tempted to mess with them. Any ideas as to which is the idle and which is the running one.

 

[sleepa]

It depends on what type of converter you have as some are different. I have a weird converter where the screws turn backwards.

By the way, technically only authorised gas installers/tuners are allowed to tune lpg. It is slightly complicated as well, took me a whole lot of messing around with the screws (until I realised mine were backwards) before I got it running right.
But, if you do want to tune it yourself there are a few write ups on the internet, just make sure you have the right converter. Also you have to start over from scratch, I guess that's not a problem for you as the worst that could happen is it doesn't run.

The sensitivity screw is the one you want to adjust. It usually has a spring around it. Have the engine running, and turn this screw out a turn or so, anticlockwise usually. If it goes all the way out with no change, go back the other way, you want to get a smooth idle sound.

The mixture screw is the other one, also controls idle, you shouldn't need to touch this.

Of course it is very difficult to tune by ear and best results will be getting it dyno tuned, but hopefully this will help you see if the converter is stuffed or not.

 

[Timmos]

Well i've only just noticed that as they were adjusting the screws they've obviously changed the idle one.. now my car won't turn on, idle or move on gas.. So i'll take a look at it in the morning..

Anyway of finding out what sort of converter i have?

 

[sleepa]

In that case this is the guide I used to tune my lpg converter
How To Tune Your LPG system at home - www.fordmods.com

To find out what converter you have first get the manufacturer name, should be on converter (I am guessing impco) then search.

Most are very similar so should all be pretty much the same, mine is different tho, it's a LANDI

Good luck

 

[TJ2009]

my lpg system is polygasauto.

bloody ruins brilliant, Tip, but maybe im wrong, check that all the screams etc from the airfilter etc are tight and secure, no holes. I had a loose screw and the car get skipping coz extra air was gettin in. tightened up and sweet.

 

[strgas]

can you post a pic of your under bonnet set up ?

 

[GMMAD]

In that case this is the guide I used to tune my lpg converter
How To Tune Your LPG system at home - www.fordmods.com

To find out what converter you have first get the manufacturer name, should be on converter (I am guessing impco) then search.

Most are very similar so should all be pretty much the same, mine is different tho, it's a LANDI

Good luck

that link isnt correct

the two screw are idle and sensitivity
to tune you will need a wideband
first screw the idle screw all the way in
then wind the sensitivity screw in (or may be out)till the mixture is around 17:1 it will start to run a little ruff at this stage(not about to stall)
once thats done scew the idle out to the mixture is 14.7:1 (this is why you need a wideband to tune)
it needs to be in gear with a/c and lights on(so the engine is under load)

once thats done the computer will control the rest

if its not computer controlled you will have a adjuster in the feed line
you will need a wideband again to set this
to set it put the throttle flat and it need to be set so it reads 14.7:1 or round about that
if it computer controlled and the mixtures arent right you would need to but a manual adjustable controller in
if its not running right you Dont touch the sensitivity screw
the sensitivity screw adjust how easily the converter switched off the idle circuit