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ok ive got a TB42S on gas
ive installed a balance line from the converter to the Clean side of my air box/filter

and it runs like C*&P!! runs like some1 is turning the key on and off
take the line off and it runs mint again
if i just connect it to the converter it still runs crap...
any ideas?
the hose it around 1.2M long could it be to long? or to fat and letting the are move to freely?

shrug!
got me buggerd
 

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nissan
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I might be waaaay off here but I thought you only needed a balance line if the donk was turbo'd or a Snorkel so would have thought you don't need one.

Mine was EFI not Carby so the mixer is in a different spot but mine didn't have a balance line and I haven't seen one on the other couple of trucks I have looked at over time.

Could easily be wrong on that tho...
 

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nissan patrol gq
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You guys got me wondering... So I went and had a look.
Mines efi and it has a 20mm hose from the dirty side of intake before air box to the center of the converter... I would say hose would be bout 600long and maybe inside diameter 12mm or so.

Maybe u have another issue,I wonder if it matters if it has to be before or after filter. I would have thought after would Be better to stop ***** getting into it. My air box has mud in the bottom.lol. No snorkel yet but it's Now my next mod...
 

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i have an rb30 turbo running straight gas and i have one line that comes off the turbo housing and connects to the inlet pipe off the turbo and then one line that comes off the converter and enters 2cm below this other line, the balance line off the converter allows for more gas to be put into the system as you are now getting greater airflow......... don`t know what it does in your situation though, my v8 on gas has the same balance line running off the clean side of the airbox, runs no different with a pod filter on therefore bypassing the balance line.......
 

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The balance pipe is fitted to help equalize pressure on either side of the diaphragm under low vacuum situations, and is only usually required when intakes are modified with certain things which create a ram air effect. Because the gas mixer is fitted before the throttle plate the vacuum created at low engine rpm is very minimal, so when you fit something which creates a positive pressure in the intake tube at low rpm the diaphragm in the converter is pushed back and starves the engine of gas. Perfect example of this is fitting a snorkel, the car will run fine while driving along but usually if you are rolling to a set of lights with the clutch in doing say 30km/h the engine will run lean due to the air being forced into a tube with a closed throttle plate at the end. which will in turn cause the engine to run rough without a balance pipe. When fitted it is supposed to be fitted on the dirty side of the air filter. Most pre 2003 commodores and falcons are fitted with balance pipes on a standard install due to the over the rad intake set up from factory. Another way to help the issue is to tighten the sensitivity screw up a fraction more on the converter and in turn correct the mixtures with the mixture screw. I have also turned the head of my snorkel backwards to, every little bit helps. Also different gas converters react differently to positive pressures, so you may hear one bloke saying his system is great while another one is saying his is **** while both driving under the same conditions.
 

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Mate I am going through the exact same thing right now. I just got a snorkel fitted to my LPG patrol as well and everything went to ****. I have turned the head around on my snorkel and it runs fine except when I am coasting to the lights as Rusty Bus said! So, I spoke to my LPG tuner guy and he said pretty much the same thing. In some cases turning the snorkel head around will fix the problem. In many other cases you need a balance line. The balance line is NOT an exact science!! You will need to get your gas dude to TUNE the gas converter once the balance line has been hooked up. My gas bloke rekons you sometimes have to screw around with it heaps to get something that works. Not fun I know but that will be why yours is running like a hairy dog. Get a bloke to tune it for you and you should be fine.
Also I dont think it really matters about the length and diameter of the pipe, air has a funny way of finding its way around and through things. The pressure should equalise no dramas as long as there are no leaks or anything.
 

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ive installed a snorkle thats why ive tryed to install the balance line.
Aaaaah, that makes sense then...

You might have to visit an LPG dude to get him to check the balance line is suitable and retune the system. The Snork and the balance line will have affected the pressures across the diaphragm as others have stated.
 

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gas is very sensitive to any change!
i needed a balance line with my snork as it ran crap, also had to turn the snork head backwards and now running sweet as!
to get it perfectly tuned you need to get the thing on a dyno while it's tuned to get it absolutely spot on.
also depend on what converter your running. i should have gone for an IMPCO as as they can be perfectly tuned for snorkels, turbo set ups etc.
might change it for one so i can turn my snork head forwrd again.
 

· BORDERTREK 4X4 & FABRICATION
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The balance pipe is fitted to help equalize pressure on either side of the diaphragm under low vacuum situations, and is only usually required when intakes are modified with certain things which create a ram air effect. Because the gas mixer is fitted before the throttle plate the vacuum created at low engine rpm is very minimal, so when you fit something which creates a positive pressure in the intake tube at low rpm the diaphragm in the converter is pushed back and starves the engine of gas. Perfect example of this is fitting a snorkel, the car will run fine while driving along but usually if you are rolling to a set of lights with the clutch in doing say 30km/h the engine will run lean due to the air being forced into a tube with a closed throttle plate at the end. which will in turn cause the engine to run rough without a balance pipe. When fitted it is supposed to be fitted on the dirty side of the air filter. Most pre 2003 commodores and falcons are fitted with balance pipes on a standard install due to the over the rad intake set up from factory. Another way to help the issue is to tighten the sensitivity screw up a fraction more on the converter and in turn correct the mixtures with the mixture screw. I have also turned the head of my snorkel backwards to, every little bit helps. Also different gas converters react differently to positive pressures, so you may hear one bloke saying his system is great while another one is saying his is **** while both driving under the same conditions.
Well put. The air intake on my missus car (dual fuel) is so effective like a snorkel (ram air effect) I am thinking of doing the same thing. On the highway when a truck passes the other way the motor almost stalls because of the big inrush of air being pushed into it from the trucks. On petrol it doesn't affect it at all.
 

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The balance pipe is fitted to help equalize pressure on either side of the diaphragm under low vacuum situations, and is only usually required when intakes are modified with certain things which create a ram air effect. Because the gas mixer is fitted before the throttle plate the vacuum created at low engine rpm is very minimal, so when you fit something which creates a positive pressure in the intake tube at low rpm the diaphragm in the converter is pushed back and starves the engine of gas. Perfect example of this is fitting a snorkel, the car will run fine while driving along but usually if you are rolling to a set of lights with the clutch in doing say 30km/h the engine will run lean due to the air being forced into a tube with a closed throttle plate at the end. which will in turn cause the engine to run rough without a balance pipe. When fitted it is supposed to be fitted on the dirty side of the air filter. Most pre 2003 commodores and falcons are fitted with balance pipes on a standard install due to the over the rad intake set up from factory. Another way to help the issue is to tighten the sensitivity screw up a fraction more on the converter and in turn correct the mixtures with the mixture screw. I have also turned the head of my snorkel backwards to, every little bit helps. Also different gas converters react differently to positive pressures, so you may hear one bloke saying his system is great while another one is saying his is **** while both driving under the same conditions.
Your quite right in the way the converter works but it actually richens up the mixture when a positive pressure is applied to the balance line not lean it out.
This is why in a turbo setup you plumb the balance line into the hot side of the IC piping. The pressure from the turbo pushes the top diaphragm down to release more gas.
 

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I have been looking for pics on how to install a lpg balance line all posts here are a few yrs old and any attachments don't open.
My converter has and open threaded hole on the front edge of the converter not the front like all posts are saying, I'm assuming this is where the balance pipe fitting screws in, any picks of converters with fittings and position of line into the air intake pipe would be appreciated a pic of my converter is attached, second image shows a plastic elbow on the back of the converter, maybe that where the hose fits on. Thanks
 

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nissan
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485 Posts
Not a Patrol but on my V8 AU duel fuel falcon. the balance line taps into the cold air intake approx 5cms in to the ram.

My old dual fuel Patrol had the balance line tapped into the inlet tube from the snorkel just inside the fender so you could see it when you lift the bonnet if that makes sense and thus way before the air-cleaner. Snorkel was facing forward.
 

· GHMBC #3
nissan patrol gq lwb,3"lift.
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I have been looking for pics on how to install a lpg balance line all posts here are a few yrs old and any attachments don't open.
My converter has and open threaded hole on the front edge of the converter not the front like all posts are saying, I'm assuming this is where the balance pipe fitting screws in, any picks of converters with fittings and position of line into the air intake pipe would be appreciated a pic of my converter is attached . Thanks
have a look on the back- yours appears to be a complex type mixer.impco/aussie b2's are simple convertors and balance port is on front plate where complex convertors -brc/omvl are on the rear
 

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Here is mine (TB48). I just sikaflexed a l fitting into the inlet pipe to the air cleaner. The other side goes into the back of the converter.
 

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· GHMBC #3
nissan patrol gq lwb,3"lift.
Joined
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3,824 Posts
I have been looking for pics on how to install a lpg balance line all posts here are a few yrs old and any attachments don't open.
My converter has and open threaded hole on the front edge of the converter not the front like all posts are saying, I'm assuming this is where the balance pipe fitting screws in, any picks of converters with fittings and position of line into the air intake pipe would be appreciated a pic of my converter is attached, second image shows a plastic elbow on the back of the converter, maybe that where the hose fits on. Thanks
that 2nd pic shows the fitting for balance line
 
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