Thinking of getting a TJ fairly soon, getting over the whole 2nd Gen scene (as a daily that is)
After doing reseach on what little information exists for Liquid LPG Injection into magnas, it seems that this is the preferable system to get. Although i can not find one thread/post that states that someone has sucessfully installed it into a magna? . I am aware of the fact the LPG system may well be worth more than the actual car is worth, but to be honest i prefer the TJ over the TL/TW or 380.

So anyway,

Has anyone actually done a LPG Liquid Injection conversion on a third gen?

Failing that, is it worth going SVI over the mixer, or is the diffrence in economy/power not that noticable?

Also can you put a donut tank in a sedan?, obviously the spare has to be relocated but it would be easier to move that when you needed extra boot space rather than a connected gas tank.

Just looking at options here...

If you travel around oz,get a mixer, lots of people can work on a mixer..
As a downside, they need to be worked on, i.e. tuned once in a while.

As for svi, the best kit is BRC, costs more than mixer, but less servicing, better economy, more power, and automatically managed.

As for a.donut, I think they are a good option, you just need to sort a spare position.
But the regular tank is a 82 litre gross, with a 65 litre fill, which with an svi system should get you 400 to 600plus on a tank.
Buy your car well, the more km you get out of her the better.

SHOOT, I assume most LPG converted cars are the mixer type as it is the cheapest, correct?
In that case, is it possible to "upgrade" to the SVI for a small fee?
How often does the mixer need tuning/servicing?

SHOOT, I assume most LPG converted cars are the mixer type as it is the cheapest, correct?

Uhuh



In that case, is it possible to "upgrade" to the SVI for a small fee?

Considering the price of the computer, Injectors, Inj Bank, New gas line to the injectors, Temp and injectors sensors fitting and removal of the old unit, and No Gov grant as its already a gas car, err no, No small fee, actually you'd only keep the tank and a few lines, but while it's being done you might consider testing your tank while they are at it, (10 Year Requirement).



How often does the mixer need tuning/servicing?
The Mixer is mechanically set, and tolerances change with use, it run off vaccuum from the upper manifold, dosed continually by a small 'O'ring injector (similar to a small round BBQ burner). A SVI system regulates supply via a similar vaccuum system, but its distrobution is timely injected of a sensor from the #1 Petrol injector, (1 gas inj. per cylinder, into each manifold chamber) and the firing order is set in the computer management system, the duration (either linked to the injector or the vaccuum) I'm unsure about. But its the accurate and timely gas dosage, (improved on DI, as it can more accurately measure liquid doses) is what sets it apart from the mixer.
If I'm way out here set me straight, but its a pretty good layman's description.

Is a mixer system fine though? Or is it a constant problem?
ie, how often does it need tuning? Does it have problems starting? Is it expensive to maintain?

Never had one, but its their reputation that has scared a lot of punters off LPG, some can run beautfully for ages and never need looking at, and you just replace the vaccuum diaphram after ten years. Or they are a constant nusance, I'd reckon they would have have them sorted out by now, or the Mech is just inadequate, or milking you.
I have a friend who's an old school Gas fitter, I'll ask and get back to you, mind you the factory mixer LPG gas system made for magna's seem OK, and I've only seen one car up here with problems in the time I've been here, and I'll put that down to a bad Mech.

The gas guy said " The old types play up all the bloody time... Alot of problems with the converter gumming up." He didn't want to know about the new direct injection cause no-one knew enough about it, so getting good service will always be hard.

For example, he was asked to fit a DI system, which he knew nothing about, and the parts/system supplier up here knew nothing about it either, so if problem came up, I'd bet you'd have expensive technicians scratching their heads, running diagnostics, and trying this and that... No thanks....

He's got a SVI system on each car, a falcon with 30 thou on gas and a Hilux with 70 thou ( pretty similar to my k's on my cars) and they (all) are problem free....

I did some more reading and the mixer is pretty much like a carburetor car. What happens when the weather changes, it will never be optimum will it?
Is SVI an DI different?
And it seems engines on gas don't last as long.

I am looking to buy a Verada with LPG already installed but wondering whether it'd be better to get one without and then install an SVI or DI on it rather than "settle" for a mixer which seems to have drawbacks

My TJII is fitted with an Impco mixer system. Mitsubishi used this system on its dual fuel and dedicated gas Magnas. It was fitted at 170K and has been totally reliable. It's serviced every 20K at a cost of $99 by the installer. When it was installed, he recommended replacing the leads, distributor cap and rotor and I took his advice. It's never backfired and the car has never run badly on LPG. Based on my experience, I would suggest buying the right car then fitting the LPG, whichever type of system you choose.

The total cost will be much higher though than buying a car already fitted with the system. Taking into account that the government rebate is about to run out as well, it may be a case of buying a 6-7K car + the direction injector system for 4.5K giving a total cost of roughly 11 grand which opens up possibilities for other cars. For example an Accord Euro which with it's 2.4L will be quite economical yet no slower than the Mitsubishi, with a nicer interior, better handling, more prestige etc

I hear good things about this Impco. Does it have the lean burn prevention option?

Edit:
The other question I had, does a dual fuel system inject either LPG or petrol, or a combination of both? I was reading somewhere and I may have misunderstood but it seemed like the dual fuel systems inject a small percentage of petrol, maybe this is to regulate the fuel/air ratio on mixer systems?

SHOOT, I assume most LPG converted cars are the mixer type as it is the cheapest, correct?
In that case, is it possible to "upgrade" to the SVI for a small fee?
How often does the mixer need tuning/servicing?

To change from a Mixer to SVI would cost around the same, if not more, than a new install. Basically none of the parts can be resued - even the tank needs to be replaced. The installers will need to remove the lines, solenoid, vapouriser, mixer plus install the actual injectors & sensors, fit new or modify wiring to match the right control unit.


Is a mixer system fine though? Or is it a constant problem?
ie, how often does it need tuning? Does it have problems starting? Is it expensive to maintain?

I've got a mixer system and so do a good amount of people here on AMC and we've seldom have problems. A mixer LPG system was installed on these engines dedicated from factory in the TL/TW magna's. It comes down alot to the installer and the maintenance. A mixer system will need to be tuned abit more often and has the potential to backfire if it is maltreated. Its not as smooth as petrol unforuntately either. Unlike with a SVI system you at a minimum need to get new spark plugs, in many cases this extends to needing new leads & even dizzy. LPG is alot harder on ignition systems and will have problems if any part of the system has a slight problem. That being said - I've barely heard of any backfire around here. Even on stock plugs the lpg system ran pretty well but I upgraded to NGK IridiumIX plugs that are smaller gapped and colder - as recommended by both Bosch & NGK. Bought the plugs for a whole $60 on ebay including delivery, when it would've cost inexcess of $130 at my local Superdodge Auto.

You should consider how long you plan to keep the car and how much you value performance. Savings are not exactly halved because you still need to run petrol through the system ever so often and the usage is higher for both systems. I run a ratio of 1:4 - i.e. for every 400kms of lpg I run through 100km's worth of petrol. At current petrol prices around $1.40 and lpg around $0.55 - the car costs me around $10/100km to run - which is quite cheap for a large car.

Mixers will use approx 16-18L/100km in the inner city burbs whereas a SVI is only marginally higher at around 12-13L/100km. For me it would've taken 9 months to recoup the mixer costs vs. almost 2 years for the SVI. The cost for SVI significanlty offset the gains for me over a cheap mixer system so I made my choice. I also have no plans to keep the car for years either so I would probably not make back much of the costs. I got lucky though and found an installer willing to do the install for the same cost as the government grant! So my conversion was basically free! As you'd expect with a mixer - there is less performance but its not very noticable for day-to-day driving. Even with a full load I'm able to overtake, climb hills with no real apparent lack of performance. Obviously if you push it hard you will notice the difference - but after all it is a magna not a trackcar of anysort so I'm not fussed at all.

As for starting - alot of the new systems start on petrol and switch to lpg soon after. SVI systems tend to wait out until the engine is warmer whereas mixer will probably just use petrol to start and then switch back to lpg leaving lpg running through the engine while cold. I've never any trouble starting the car and I drive it everyday of the week. The only time I've had issues with the lpg system was when the air intake sensor kicked the bucket and when I misadjusted the throttle position sensor. Both of these were not lpg specific issues except it the system was more sensative to it.

I've been running LPG in Magnas for 7 years now and never had any issues with them.
They are all mixer setups (including my TJ VRX) and the power loss is minimal.
If you get the job done well and maintain it (general car maintenance) you will barely notice the power difference.
I start my cars on petrol and run them until they warm-up, then I manually switch to LGP. This just means I use less LPG when the engine is cold and I finish up with a running cost of about $7-50 per 100klm.
You do need to regularly run petrol through the system if you want to keep it as dual fuel, or you can run it as a LPG only system (see your installer about this before you get it done).
My cars (combined) have done over 200,000klm on LPG and have never had any issues. Also, running duel fuel when travelling I can get across the border into capital cities without copping country fuel prices, about 1,200 to 1,300klm between refuelling if I really push it.

I have used LPG on vehicles for nearly 20 years. I have had a TM and a Tf magna - both on gas and petrol, but mainly gas. The TM was fitted with gas at 230000 km and I sold it at 345000 km. The TF has now done 230000 km and only recently I have had slight problems with it.

Fuel consumption on both averaged at about 11 L/100 km on highway running (most of the time) and as bad as 14 L/100 km for short stop/start runs around town. I cannot notice any difference in performance on gas or petrol. If anything, I think the car is smoother on gas, but maybe it is all in the mind... I also have a NL Pajero with 230000 km on it - virtually all o LPG. That is delightful to drive, but is more sensitive to tuning than the Magna. The main difference is the ignition leads - 5 mm dia for the Pajero and about 7 or 8 mm for the Magna. The savings in fuel costs have nearly recovered what I originally paid for each vehicle, and the savings go on and on - the more I drive, the more I save.

Thank you for the detailed responses, they are very helpful.

It seems that the mixer is competent enough but the main advantage of the SVI is not so much the marginal fuel savings but rather the smoother more responsive engine.

Can someone tell me why it is that a dual fuel car has to be ran on petrol periodically as well?

I'm lookin forward to the answer on this one, I hardly ever run petrol, and would be lucky to use 1.5 tanks of petrol a year. Or 15 Litres every 2-3 months. I know they used to run petrol for the valve seal condition, but since leaded went out, I haven't cared.
The missus does the occasional squirt on saudi motion lotion in the 380 tho....

Can someone tell me why it is that a dual fuel car has to be ran on petrol periodically as well?

You only run it on petrol if you want to run it as a dual fuel car.
I ran my series 2 as LPG ONLY for 4 years and never had an issue.

The issue with not running petrol through the engine often, is usually the injectors that get blocked up after extended periods of time. Furthermore - the lines can also get all clogged up not to mention potential fuel pump & filter problems if the petrol is left sitting in the tank for too long. It does heavily vary case-by-case though but I remember my dad's old falcon ended up only being able to work on lpg as he always used to only run lpg through the engine. For him to have the lines replaced & injectors cleaned up.There is also a rumour that lpg is a drier fuel as well but this is always refuted by others so I cannot comment. All I know is that when you put oil & petrol together they seperate so I'm not confident in Petrol's properties to lubricate the engine either.

Engine wear for an LPG powered engine is considerably less than that for an equivalent petrol powered engine. I recall reading some years back about a water taxi service on the Hawkesbury River which converted their outboard motors to LPG. They claimed 5 times the engine life and of course cheaper fuel as well.

If you do a lot of short runs, you will get a buildup of condensation in the engine oil. The condensate from LPG burning is a lot more acidic that that of petrol, hence they put out special LPG oils which contain more alkali substances to counter the acid buildup.

Personally, I don't use these oils - I just change the oil fairly frequently (typically every 5000 km). Replacing oils is a lot cheaper than replacing engines or bearings.

Erad - not trying to argue your point but being a water taxi I'd imagine the engines would be seldom turned off. This does significantly affect the engines wear as well. Just something to consider. Alot of the time this is why taxi's clock over many more km's than normal domesticly used cars and why I loathe the statement "Falcon's are great - just look at how long taxi's go for!"

I agree with the oil. The engine was designed for petrol and therefore needs that kind of oil. Dedicated LPG engines usually have higher compression than petrol ones. I usually replace my oil at 15,000km as per the requirement but I don't cheap out and I buy Penrite HPR10.

It seems like we won't be able to get a clear answer on whether LPG wears the engine more or not. Personally I have read, and believe, that LPG does cause more wear and tear on the motor.

And yes, taxis are a poor example as they are always warm hence there is no start up wear or cold driving wear that normal cars are subjected to.


Another question of mine, if a dual fuel car has to be run to avoid clogging up the system etc, would it be possible to completely drain all petrol, and avoid clogging this way or is it not a matter of petrol being in the system?

I think some older ones start on petrol then switch to gas, also if your lpg system leaves your fuel pump circulating still (e.g. to at least keep the lines clear) then havving it run in a dry tank is a bad idea as the petrol pump will overheat.

SPETZ: If you have a dual fuel system, you must always keep the petrol tank at least 25% full. This is becaue the petrol pump runs all the time and if you run it dry you will ruin it very quickly.

I have a Pajero in which I have installed a relay to the petrol pump power feed. When I run on gas (most of the time), the petrol pump is not operating at all. In this way, I can go to remote places and run on petrol, leaving me with a full tank of gas as a reserve. I can then run to empty on petrol and switch back to gas when I know that I can get gas at the next stop. And I don't ruin the petrol pump. In this way, I have driven round the block twice now, using only 2 tankfuls of petrol on each trip (18000 km - towing my caravan). I haven't bothered ti isolate the petrol pump on our Magna because that rarely gets to places where gas is scarce.