Thread: lpg mixture settings

I'm not sure how others do it, but we use(d) an exhaust sensor to give us the fuel/air mix

i think this is the main mixture screw....it has to be set using an exhaust gas sensor & preferably having the car on rollers.if it is not set correctly you will have all sorts of trouble including possibly burnt valves

the screw on the gas converter may be the idle mixture,which is also set using an exhaust sensor

Originally Posted by neil 90

Hi, where the hose goes to the mixer on the engine theres an aluminium adjuster in the line. ...

Ooh! I didn't know that you had to adjust the aluminium in an LPG system?

Originally Posted by Slunnie

I'm not sure how others do it, but we use(d) an exhaust sensor to give us the fuel/air mix

Having only watched as this was "tuned" Slunnie is correct, you need an exhaust analyser to do it. Too rich and you are wasting gas and too lean you lose performance and risk burning exhaust valves.

Diana

I was always taught to run it to 3000 rpm adjust the mixture until it ran smoothly then wind it out half a turn.
The purists would say that you need all the equipment but this is how most workshops in Australia (read 75% of them) will do it when you book it in.

Duane

Originally Posted by djam1

I was always taught to run it to 3000 rpm adjust the mixture until it ran smoothly then wind it out half a turn.
The purists would say that you need all the equipment but this is how most workshops in Australia (read 75% of them) will do it when you book it in.

Duane

You will find at least one thread on here from me when I was learning about LPG tuning.
I did as above and trust me that you will know all about it if it is running lean. Quite simply you will have no or greatly reduced power.
Since you are not starting from scratch and it runs etc as it is, you could try turning the power valve in a bit (I find 1/4 turns make noticeable differences) until you lose power and then wind it out a bit until you are happy.

I have no idea how lean it needs to be to start burning valves but mine is fine so far.

Also be very careful about turning the valve out as there is nothing to stop it coming all the way out and turning it into a flame thrower. I wound mine all the way out with the engine off so I new how far would be too far.

Originally Posted by Utemad

You will find at least one thread on here from me when I was learning about LPG tuning.
I did as above and trust me that you will know all about it if it is running lean. Quite simply you will have no or greatly reduced power.
Since you are not starting from scratch and it runs etc as it is, you could try turning the power valve in a bit (I find 1/4 turns make noticeable differences) until you lose power and then wind it out a bit until you are happy.

I have no idea how lean it needs to be to start burning valves but mine is fine so far.

Also be very careful about turning the valve out as there is nothing to stop it coming all the way out and turning it into a flame thrower. I wound mine all the way out with the engine off so I new how far would be too far.

every one talks about been lean in fuel mixture and its true about valves mainly in older motor engines. But if you are to rich and running a catilic/convertor in your exhaust system you'll turn it into exhaust brake as the honey comb will burn/melt :mad. Not good if you are miles in the scub with a fully welded exhaust system

Originally Posted by djam1

I was always taught to run it to 3000 rpm adjust the mixture until it ran smoothly then wind it out half a turn.
The purists would say that you need all the equipment but this is how most workshops in Australia (read 75% of them) will do it when you book it in.

Duane

When i did my first conversion, my BIL told me to do it this way and adjust the mixture till it pops then wind it back a bit, i never bothere to get tuned by analyser as it ran fine and got the average mileage i was expecting. If you fit an O2 sensor you can get a kit from Jaycar that reads the mixture and will give you a reading so you can adjust correctly.

Originally Posted by NOFUSS

every one talks about been lean in fuel mixture and its true about valves mainly in older motor engines. But if you are to rich and running a catilic/convertor in your exhaust system you'll turn it into exhaust brake as the honey comb will burn/melt :mad. Not good if you are miles in the scub with a fully welded exhaust system

this is why i would not try to set the mixtures without an exhaust analyser.

air leaks on inlet manifold can also be problems etc

we run a fleet of vans on lpg,once set they generally go at least 120k to 150k without having to be touched.

ummm.....make sure you have put in a new air cleaner before setting mixtures or you will have trouble when you change it later.

also do a search on this forum as there is heaps of info on lpg around

good luck

saw a late model pajero with burnt valves not long ago...lpg fitted when new,so late model cars can also have problems if lpg is not set up properly