Land Rover Owner International

I'm just wondering just in case I have to make adjustment to my lpg while out somewhere if anyone call tell me what each screw/adjuster does. I'm not sure of what make my vaporizer is fitted to my 3.5 EFI rangie but the rangie is running very sweetly - possibly better then on petrol. The lpg is a single point system.

Here are some pics, hopefully people can make sense of them and tell me what each screw/adjuster does. The thin pipe in the first pic goes to the device to hold the flap open in the air flow meter when on lpg.






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G reg Rangie 3.5EFi.

If you tell us what the lettering on the vapouriser is it would help.

I suspect the screw with the spring is for adjusting the idle mixture as that's the function of a similar screw on mine - different vapouriser to yours which is why I've used the word 'suspect'.

The one in the vapour line in pic 3 is a 'power valve'.
Is basically a metal tube with a bolt threaded into it. By adjusting the bolt in or out you control the amount of gas going to the ring. If the bolt is too far out you will run very rich & use LOTS of LPG. Too far in & the car will get to a speed & won't go any faster. Be careful of adjusting it too far in as you may get flashback due to lean mixture.

Worth screwing them all the way in, being careful to count & make a note of how many turns/part of turns that is as it will give you a basic setting figure if you need to do anything to the system in future.


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1986 RRC 3.5EFi LPG

Ooops, that will teach me to look at my own pics, I hadn't even noticed the writing on the vaporiser

I've now gone and checked and it says Stefanelli, made in Italy.

What you said makes sense, the springs being there to stop the adjusters moving on their own accord I take it but what controls the idle speed? Also what is the brass? screw at the bottom of the vaporiser for?


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G reg Rangie 3.5EFi.

RangieV8 wrote:

Ooops, that will teach me to look at my own pics, I hadn't even noticed the writing on the vaporiser

I've now gone and checked and it says Stefanelli, made in Italy.

What you said makes sense, the springs being there to stop the adjusters moving on their own accord I take it but what controls the idle speed?
The amount the screw is in or out controls the amount of gas allowed through at idle so its really a mixture screw. Adjust in conjuction with the normal idle screw on the plenum, but I found with mine that once set to normal idle on petrol its just a matter switching back to LPG & turning the vaporiser mixture screw in or out until it settles to a smooth idle.

Also what is the brass? screw at the bottom of the vaporiser for?
Pass. It might be a drain plug to allow draining of 'heavy ends' during servicing but I don't know.
Suggest web search to see if you can find anything for Stefanelli or hope someone on here also has one fitted!

BUT. If its running fine without any problems then other than making a note of the settings of the screws I'd leave it alone!


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1986 RRC 3.5EFi LPG

I think Paint Man is correct but not 100% sure so here goes?

On the vaporiser
Spring screw?
There are usually 2 screws on a vaporiser
One controls the mixture by acting on a diaphragm needle valve inside the vaporiser.
There should also be another screw to adjust tick over, this could be the spring screw?

Power Valve sort of determines how much fuel gets through to the motor, or how much vacuum is on the diaphragm in the vaporiser.


Simple answer to adjustments is don’t move anything if its working well!!!!!!
Moving the spring screw too far and she will run too rich or too lean, if it runs lean it will backfire which will do wonders for your AFM
Mowing the power valve will make it rich or lean also, if she is sluggish at high revs moving the power valve out will do the trick.
To set the system up you do need a co2 meter or one of these

http://www.tinleytech.co.uk/acatalog/System_Upgrades.html

the VIP 100 controls mixture via the power valve when cursing, it also tells you how your mix is at idle. I put one on mine and am getting around 16mpg on a run.

The screw at the bottom is most likely a drain

Where is it injecting the LPG?
Did you adjust the ignition timing for LPG?

As I think I mentioned at the start of the topic the system is running well on gas at the moment although the idle speed is a little high for my liking (its about 1100rpm), I was more interested in what each adjustment does in case I need to work on the system or adjust it in the middle of no-where.

The timing has been adjusted for lpg, it pinks slightly on petrol though.


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G reg Rangie 3.5EFi.

Not knowing the vapoiruser cant be 100% but I would go for the spring screw being that to adjust the tick over.
Did it change recently? It could be running slightly rich due to cold weather..colder engine on short runs.
If you adjust it outwards/inwards it should increase/decrease the tickover speed. If its like mine try withdrawing it form the unit at standstill and counting the turns, it should be a pointed needle inside, like a float needle off a carb

The idle has always been on the high side since I've had the rangie (a year next month) and they didn't comment on it at the last mot.


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G reg Rangie 3.5EFi.