Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: richard on 03 February 2010, 20:02:15

Title: LPG mixture
Post by: richard on 03 February 2010, 20:02:15
Does anyone know if I can adjust the mixture levels of my LPG.Its running rich (I think) and need to lower it , its turning my emissions light on!!!

Read somewhere that you can adjust it on the vaporiser/mixer

QUOTE from another forum
]I'm a happy bunny!

After doing a routine service on the 90 the other day, I decided to play with the mixture screw between the mixer and the vaporizer, my first attempt ever!

I just turned the mixture screw down, then revved the engine, and kept turning it down a quarter turn until the engine was under-fueling on revving, then turned it back up a quarter.

As a result it still runs and starts the same, no loss of power over the previous set-up etc.

I used to get 2.7 mpl, which is 12.27 mpg, driving half sensibly, half with high revs doing about 60mph.

After the play (which I did 50 miles into a full tank) I did 100 miles, and then filled up.
This time it returned 3.1 mpl (14.09 mpg), and it had been given a fiar thrashing in terms of keeping the revs up!

So hopefully when I next fill it up, I'll get around 3.3 mpl (15 mpg) even after being driven hard!

So that's the last time I hand over £100 for the local LPG fitter to check and re-tune the system!!! (unless I smell a leak!)

Any thoughts ??
Title: Re: LPG mixture
Post by: tunnie on 03 February 2010, 20:03:52
Stag kit is adjustable via laptop software, not sure on other makes. Worth posting up what kind of system you have fitted, also is it SGI or Mixer?
Title: Re: LPG mixture
Post by: Entwood on 03 February 2010, 20:06:46
As he mentions "mixer" .. and an SGI would have the amount of LPG controlled by the injector timing ...

My guess is it must be a mixer system ...  :)
Title: Re: LPG mixture
Post by: tunnie on 03 February 2010, 20:09:30
Quote
As he mentions "mixer" .. and an SGI would have the amount of LPG controlled by the injector timing ...

My guess is it must be a mixer system ...  :)

Did wonder that, but have seen vaporizer referred to as evaporator & mixer, just wanted to ask the question to make sure  :y
Title: Re: LPG mixture
Post by: richard on 03 February 2010, 20:20:23
sorry all 2.2 auto 2003

believe its beacon pharos system / thats what is says on install receipt but that was 7 years ago.

How can I adjust it ???????
Title: Re: LPG mixture
Post by: Lazydocker on 03 February 2010, 20:56:40
Assuming it's an injection system, and not an unsuitable mixer system, the mixture is not adjustable directly. Injection systems work (generally) by "piggy backing" on the petrol ecu... Adjusting the LPG injector timing to give the correct mixture.

If it is a mixer system, which is possible and will work, just runs the risk of a backfire destroying vital inlet components, then unless there is a serious problem leave well alone. You really need to get the emissions checked on an exhaust gas analyserto be sure it's not running lean though.
Title: Re: LPG mixture
Post by: tunnie on 03 February 2010, 20:58:13
Richard, you need to confirm for sure if its mixer or injection.

Mixter - LPG sent in via throttle body

SGI - Direct injection into the cylinders, this will be done on the inlet manifold

 :y
Title: Re: LPG mixture
Post by: richard on 03 February 2010, 21:12:51
Its an injector system.

I know cause i had to have 4 replaced !!
Title: Re: LPG mixture
Post by: Kevin Wood on 03 February 2010, 23:57:32
Best thing would be to try to get hold of the mapping software for that system. You can in theory turn down the vapour pressure from the vapouriser but it's a blunt instrument as it will reduce it across the board.

Besides, the software  will allow you to do diagnostics on the LPG system too.

Kevin