99 GU ST on LPG

[Darian]

Hello All,

Have just bought a 99 GU ST on LPG, Auto, but am getting terrible fuel economy.

The existing LPG Sysytem was fitted from new and is a Parnell, I believe. The main LPG tank holds about 90+ usable litres of gas (and the sub-tank about 30 litres of petrol) but, wait for it, I am only getting 220km per LPG tank! I know it's a big, heavy vehicle but I can watch the guage drop as I drive!!!

The LPG tank was replaced with a new tank early last year - 2011.

It was apparently only tuned and serviced a few months before I got it - and the fella I got it off said I should get between 350 - 400km per tank. That would be nice! The fuel guage also was reading backwards but I changed the resister guage on the tank and that now reads in the right direction but never shows a full tank - it only ever goes to 3/4 full on the guage. The Petrol guage only reads the same amount, about 3/4 full when the tank is full.

I intend to try and find a good LPG Service Centre - can anyone recommend a good, reliable and honest company to deal with in Adelaide?

Any help or suggestions would be greatly appreciated. It's driving me insane!!

With Many Thanks in advance,

Darian.

[Gruntgu]

G'day Darian, i just bought pretty much the same vehicle at the same time with a little better economy, i was getting about 250km per tank of gas with a loaded trailer and a vehicle full of people and the dog traveling from QLD to S.A just moved back here as the wife is from here.

My gauge's are all over the shop too mainly the main tank gauge as it is being used for gas, the most i've been able to get in the lpg tank was 80 litres and it suppose to be 90 litres usable.

Anyway i have'nt been much help to you but would have asked the same questions so hopefully with the right answers you'll be a help to me :thumbup:

Grant

[Darian]

G'day Grant,

Welcome back!!

Mine seems to be getting the same economy - 220km per LPG Tank - whether it is loaded or empty. Pulled a trailer around with 1 and a 1/2 tonne of rubble for a couple of trips. Patrol pulled the load beautifully. Then ran around with no load or trailer and it didn't make any difference to the economy.

I was wandering if a newer type or style of LPG Mixer might be needed.

Not knowing much about Gas yet I'm hoping the wise on the forum can help point me in the right directions and let me / us know what to ask for and to watch out for.

Here's hoping we can solve the consumption problems.

Cheers,

Darian.

[Darian]

G'day,

I have been reading further in the forums and perhaps cleaning the MAF may help a little. Whilst this seems to mainly help with throttle and lag, it seems from what I have read that it can also affect fuel economy.

I have spoken to a Gas Installer and he is going to put it on the Analyser but said it sounded like there could be too higher pressure in the system /mixer as well.

It looks as if the MAF has been out at some stage before as it has normal "philips head" screws in place of where the "torq head" screws would have been. I haven't been brave enough to pull the MAF Sensor out yet.

Does / would anyone recommend that I clean the MAF Sensor first before the Analyser, or am I best just to wait and see?

As always,

Thanks in advance,

Regards,

Darian.

[altech]

Hi Guys, 97 GU ti , did a small trip very happy that I was getting 420 plus of LPG and 220 plus for the Sub tank of petrol , with gauge lp does show 3/4, then at 300ks from trip meter , it show empty , but I said to myself i just let it run out ,then 420k on highway ,change it over to petrol, only had the patrol 3 weeks today, still happy and LPG price per litre :-) cheers Alex

[Darian]

G'day All,

Found out that the mixer / converter has worn out. Poli Auto was the manufacturer and the installer was Parnell. The "Gas Man" told me that the Poli-Auto (as with most mixers) wear out between 8 - 12 years. He said that the Poli Auto Converter has a small mixer (about 25mm or 1") and that it really is too small for the size of the motor and the weight of the vehicle.

So with that being said I have decided to rip the whole system out and go with a new LPG Injection System. This will give me back (and better) what the economy should be on LPG as well as returning the original power and torque as well as doing the same for the petrol system.

Has anyone done this to their Patrol and what was the outcome?

How do the under-bonnet pieces look and fit? How and where does the fuel gauge now go? Can I switch the sub-tank gauge wiring for the main-tank wiring so that the sub-tank uses the main take gauge (does that make sense)?

Any photos, info, words of wisdom - all greatfully accepted.

With Thanks,

Darian.

[Gruntgu]

Good to hear you got an answer, i'll be looking forward to seeing how the new system works for you if you go down that path i'll have to get mine looked at in the not to distant future. :cheers:

[YNOT]

G'day All,

Found out that the mixer / converter has worn out. Poli Auto was the manufacturer and the installer was Parnell. The "Gas Man" told me that the Poli-Auto (as with most mixers) wear out between 8 - 12 years. He said that the Poli Auto Converter has a small mixer (about 25mm or 1") and that it really is too small for the size of the motor and the weight of the vehicle.

So with that being said I have decided to rip the whole system out and go with a new LPG Injection System. This will give me back (and better) what the economy should be on LPG as well as returning the original power and torque as well as doing the same for the petrol system.

Has anyone done this to their Patrol and what was the outcome?

How do the under-bonnet pieces look and fit? How and where does the fuel gauge now go? Can I switch the sub-tank gauge wiring for the main-tank wiring so that the sub-tank uses the main take gauge (does that make sense)?

Any photos, info, words of wisdom - all greatfully accepted.

With Thanks,

Darian.

I fitted (I was a qualified LPG installer) Parnell vapour sequential injection to my last GQ 4.2 EFI, also fitted it to my wifes BA Falcon. The Patrol was getting about 400km to 90 litres of gas. LPG injection means you don't have a mixer restricting air flow into the engine, and having the gas injected so close to the intake ports meant no backfires.
The converter for VSI is smaller than most conventional converters so fitting it isn't a problem. I made my own injector brackets as per the photo.

http://i758.photobucket.com/albums/xx224/tonyh01/P1010345Small.jpg

Tony

[Ben-e-boy]

tony does that setup reduce the "lagging" effect due to the advanced timing of gas???

[YNOT]

tony does that setup reduce the "lagging" effect due to the advanced timing of gas???

I never felt any lag. With VSI there is no need to advance the timing or fit different spark plugs as you would do with older gas systems.

Tony

[Ben-e-boy]

I never felt any lag. With VSI there is no need to advance the timing or fit different spark plugs as you would do with older gas systems.

Tony

righto I was thinking of of the old gas fed 351's etc. when I commented

[Darian]

G'day Tony,

Many Thanks for the reply. Am just hoping for a nice neat job as yours is in the photos. Will have a word with them when I drop the car off.

I am looking forward to having the Injection system fitted. This should solve my terrible economy (and power) issues. Will report back as soon as I have the car back and let all on here know.

On a side note - my temperature gauge seems not to be working more often than not - it usually only works when I'm heading downhill and then only very rarely. The door light is also turning on for no reason in the dash even though all dooors are closed. Could this be a bad earth for both the door switch and the temperature gauge or might there be a problem with the dash or instrument cluster itself?

Cheers,

Darian.

[Darian]

G'day All,

Have had the Vapour Injection System fitted and a very happy so far.

It's only been on there 2 days and I've just filled up so we'll see how it goes on the economy side of things. I have to take it back in once I've done about 1500kms for a re-adjust and fine tune.

Power seems to have definately improved. I know it's a big, heavy car but power and acceleration are defininately better - and what I would describe as "no lag" like when you "took off" with the mechanical Gas System.

They have done a good job under the bonnet as well. Nice and neat to me anyhow. I don't have a second battery and that's the position they mounted all the "gas gear" in but at this stage I'm not worried at all. The little LED Gauge and switch that comes with the new system controls the system as normall but he (we) decided not to use the LED Indicator Lights for the Tank Level but retain the original guage working in the dash. It's easier to see.

The Temperature Gauge that was not working most of the time must have had something to do with the old style Gas System. It is working perfectly now. I can't explain it but perhaps the problem in the old worn out converter caused the temperature guage to act erratically - who knows.

Will report back once I've used a copule of tanks of LPG - but at this stage that will (hopefully) take twice as long to use now that the system is "fixed".

Regards,

Darian.