Thread: GAS Vapour Injection?? Help!

I have a Deacon vapour injection system on my 94 D1 with a 4.6 and it works great. It has slightly more power on gas and the fuel economy is the same. It starts on petrol and then changes to gas once the engine has warmed slightly. On my vehicle I have twin under car tanks and a rear quarter tank.
The D1 is a banked injection system rather than sequential due to the efi system in use. That means it pumps fuel into one bank of cylinders and then the other. You do notice a very slight hesitation when the vehicle changes from petrol to gas due to this. The D2 is sequential. So it supplies fuel to each cylinder individually.
I would not convert to full time gas for touring because if you run out, that's it your getting towed. There are also times when you wont be able to get gas.

hey cheers mate

I have the smaller Fuel Injected 3.5 V8 in mine. If i converted it to gas i would get a smaller petrol tank installed, so that it could always be run on petrol in emergencies. How much did it cost to get the gas vapour injection system installed? where abouts did you get it done?

Sorry, but you're not thinking logically...

Your Gas range isnt too shabby... You could fit a UniChip / Haltech co-processor and dual map your V8 (you need to go down the road of having timing ECU controlled) to run spot on on Gas and Petrol using the system you have...

This will be around $1500.00 depending on where you get it done.

To go sequential will cost you a LOT, plus the cost of the tanks etc...

They would buy a heck of a lot of fuel...

The Petrol is the range giver, if touring, you'll need a liquid fuel source, as well as Jerry cans or a larger petrol tank on some trips.

Right now, you have the best deal.... Stick to it and just improve its tune.
You wont get much more than 260km from 60 litres of LPG.

Originally Posted by Dart

hey cheers mate

I have the smaller Fuel Injected 3.5 V8 in mine. If i converted it to gas i would get a smaller petrol tank installed, so that it could always be run on petrol in emergencies. How much did it cost to get the gas vapour injection system installed? where abouts did you get it done?

Hang on! Is it on gas or not?

tombie, I think he might be talking about a full time LPG only conversion.

Im backing you on this one theres no real point in converting to LPG only especially when touring as the money you spend on doing it takes a long time to recoupe Especially if the trend in LPG prices follows that of diesel (remember when diesel was cheaper than petrol?)


It might be worth changing the tanks out for the single Large tank in the back but that costs you space. If your going to convert it over to a drawer system you can manage the lost space a little better but you still loose a fair chunk of your low down and over the axle space.

If you were VERY VERY serious about doing the conversion you might just want to consider a liquid injection system which is the next generation of LPG and promises to get the economy in terms of K's per liter OR the total power output of the engine up nearer to that which is achievable with a petrol engine. Prepare to pay for it tho.

Back in March when we went to Albury, my fuel pump failed at Tumbarumba so I had to run entirely on LPG.

The P38A with Sequential Vapour Injection really had problems starting on LPG. It would crank for a long time before firing. I was beginning to despair and worry that I'd have to have the car flat-bedded home. I didn't need that as I was already stressed by the death of our son (the reason for the trip).

Another issue is that my LPG ECU only permits 50 LPG starts. After that it has to be reset. (I reset it when I got home - I have the software for it.)

If you go LPG only, make sure the LPG ECU (if used) won't lock you out after a certain number of starts.

Hey guys, thanks heaps for your insight, it's honestly really useful! And yes my car is currently setup as a dual fuel vehilce, so yes I already have the basic gas system installed and working.

It's kinda comforting to hear that my gas isn't running too shabby, i guess i knew that petrol was the way to go for touring, especially for more remote locations.

When running my car on gas, I just get sick of refueling so often due to the small tank, so if anything i might sacrifice some boot space for a single larger tank, so i'm not refueling as often. Does anyone know what it might cost to replace the scuba tanks with one larger tank??
I can build shelving/platform around it myself to maximise what space i have left.

Depending on how much money i have (not much) i might get it dyno tuned too. From what everyone has said, it seems that getting gas vapour injection is really expensive and may not be worth my while...and may be unreliable at times...honestly how can people afford to drive around Australia these days with our fuel prices!!! It's cheaper to fly, but no where near as fun as doing a road trip with friends!

thanks again guys,

Dart

if you have the trio of tanks fitted you can have additional tanks fitted to the system.

so long as your happy with your current range on petrol and have already decided to sacrifice some internal space why not just plumb on another LPG tank?

other options to get more range include replacing the fuel tank with the 2 pod tanks that fit inside the sides of the vehicle above and behind the rear wheels, this gets you about the same amount of useable fuel petrol and frees up the space where the fuel tank used to be for more LPG tankage or just gives you more fuel range if used in combination with the existing petrol tank. Ive also seen one D1 which had had a body lift to accomodate some taller rubber and it had 2 pairs of 2 LPG tanks strapped outboard of the Chassis rail underneath bodywork (dont know how legal That would have been) in pretty much the same position as the fuel tanks on a Series or a perentie.