LPG TuneUp

[Kulwinder]

hi
i have a problem, not with my commodore, with my Hyundai Grandeur XG 1999.
It is dual fuel. It goes very smooth, fast, but drinks too much Gas. nearly 64 litters up to 280-300 ks.

no mechanic could take it to more. I expect more than 400ks. (local) because it has only 3.0L V6 motor.

I want to adjust mixture my self according to my need.
Does any one tell me how to adjust mixture?
there are two small screws on converter and one big one on the pipe with goes to throttle body.
I have put some photos of these.

Plz help....

[strgas]

who replaced the power valve with a manual valve ? "one big one on the pipe"
the two screws on the side of the convertor are sensitive and idle mixture screws . the one sticking further out is the idle screw and the other is for sensitive ,
the larger screw is the power valve which effects high speed and cruise mixtures , it should have a O2 controlled power valve not a manual valve fitted .

[HamaTime™]

That sort of economy is about right for gas. You got to remember that LPG despite having a higher octane level (110-118) compared to 91-98 unleaded petrol, LPG has about 30% less energy per ml/g (whatever measurement). I get 250 k's out of a 60ltr tank on my VS around town, alot higher on the highway. But, 64ltrs into 300 k's works out to be around 20-21Ltrs per 100k's.

Another reason for the bad economy is the type of gas system. From what I can see in the photo's you have a Gas mixer/carby styled LPG system rather than an injection system, this is very uneconomical due to the delivery of gas into the intake tube before the throttle body, therefore sucking in a gas/air mixture. This is again is very uneconomical, and your fuel usage does not surprise me at all.

My point? This is normal

[Kulwinder]

hi thanks for reply. the power valve was replaced by mechanic one year ago, just after two months when i put gas in my car. He said my car needs manual valve!!

One more thing is when they tune up my car they never tune to "OK" (Yellow LED) sign on mixture computer. It always stays on "+" (Red LED)
Can you plz tell me how these screws work.

[Kulwinder]

I can under stand Idle Mixture. As I search on internet. It is mixture of gas and air.
But what is sensitivity screw. How it works....

[The Recidivist]

Some may think this is O.K but personally, I think your LPG consumption of 65 l/300 km is far to high.

My VX2 wagon regularly travels nearly 400 kms on 40 litres of LPG of mixed driving i.e. country (2/3) and city driving (1/3).

On the highway I try to sit on a fairly constant 100 kph.

I'd be taking it to a place that specialises in LPG tune-ups, instead of trying to tinker around with it myself, and possibly making it far worse.

[HamaTime™]

Some may think this is O.K but personally, I think your LPG consumption of 65 l/300 km is far to high.

My VX2 wagon regularly travels nearly 400 kms on 40 litres of LPG of mixed driving i.e. country (2/3) and city driving (1/3).

On the highway I try to sit on a fairly constant 100 kph.

I'd be taking it to a place that specialises in LPG tune-ups, instead of trying to tinker around with it myself, and possibly making it far worse.

Again, as I said in my post, what sort of Gas system do you have? Air Mixer styled systems which deliver the gas vapour into the intake tube have alot lower economy levels.

[strgas]

hi thanks for reply. the power valve was replaced by mechanic one year ago, just after two months when i put gas in my car. He said my car needs manual valve!!

One more thing is when they tune up my car they never tune to "OK" (Yellow LED) sign on mixture computer. It always stays on "+" (Red LED)
Can you plz tell me how these screws work.

.

Your mechanic told you that ??? Infact your car needs to have an O2 controlled feed back system to comply with emission laws , manual power valves are for non O2 controlled cars , the sensitive screw controls the response time of the convertor and the movement of the secondary diaphragm , correct adjustment of these screws should only be done by a qualified LPG installer and not some mechanic who doesn't understand whats hes doing

[The Recidivist]

Who's - mine or Kulwinder's?

Mine was a factory fitted option that was installed when the vehicle was purchased new. A 'Flashlube' injection system has also been fitted which lubricates the upper cylinder area when the vehicle is running on LPG.