How to reduce Fuel Use?

[dmck Junior Member Find all posts View Profile Close dmck]

i ended up getting 295 out of the last tank. was a bit better but i want to take a look at the throttle position sensor...

i put this increase to tyre pressure and giving the throttle body a clean...

[dermie75 Member Find all posts View Profile Close dermie75]

I tried walking for a while... Didn't last long though...

I made it as far as the bus stop Matt, didn't have to walk then :P

[Guest Close Guest]

Can you provide L/100km figures as this is better than km per tank. Maybe you're putting less in a tank?

[MidLifeCrisis Out of control poster! Find all posts View Profile Close MidLifeCrisis]

I made it as far as the bus stop Matt, didn't have to walk then :P

I let me mates drive and tell them "how great there rigs are" Saves a s&*tload in fuel and they even pick you up at the front door.

[dmck Junior Member Find all posts View Profile Close dmck]

sorry. its 295 for 68L lpg = 23.05L/100km

ive been back at uni so dont drive too much now but im not the biggest fan of public transport...

[croozza Avid PP Poster! Find all posts View Profile Close croozza]

sorry. its 295 for 68L lpg = 23.05L/100km

ive been back at uni so dont drive too much now but im not the biggest fan of public transport...

You will never get the same economy on LPG as you do on petrol, so what your getting on LPG is about right as it is normally about 40% to 50% extra

[dmck Junior Member Find all posts View Profile Close dmck]

I understand that.

I was getting up to 400Km/68L on lpg only 12 months ago. 17L/100km
But now its up to 23.05L/100km on a good tank.

Thats where my issue lies... the fact it has changed so dramatically in just one year.

[croozza Avid PP Poster! Find all posts View Profile Close croozza]

I understand that.

I was getting up to 400Km/68L on lpg only 12 months ago. 17L/100km
But now its up to 23.05L/100km on a good tank.

Thats where my issue lies... the fact it has changed so dramatically in just one year.

Many things can influence the consumption rate.
1. Weather conditions, ie wind, rain, temperature, ect
2. Traffic conditions
3. Poor driving habbits by OTHER drivers, (this is where other drivers are erratic in their driving)
4. Engine tune
5. Tyre pressures/type
6. Weight in the vehicle
7. Fuel guage becoming inaccurate.
ect, ect

[williade Avid PP Poster! Find all posts View Profile Close williade]

Have you had a compression test done? What about the condition of your spark plugs and HT leads?

I'd get a mechanic to check the ignition timing too.

[croozza Avid PP Poster! Find all posts View Profile Close croozza]

Have you had a compression test done? What about the condition of your spark plugs and HT leads?

I'd get a mechanic to check the ignition timing too.

Isn't the timing electronically controlled by the ECU, if there is a timing issue then he will need a new ECU.

[williade Avid PP Poster! Find all posts View Profile Close williade]

Isn't the timing electronically controlled by the ECU, if there is a timing issue then he will need a new ECU.

It is electronically controlled. The timing could also be thrown out by faulty cam/crank angle sensors too.

[croozza Avid PP Poster! Find all posts View Profile Close croozza]

It is electronically controlled. The timing could also be thrown out by faulty cam/crank angle sensors too.

If they were the problem, the engine would not run, and if it did, not very well.
Reading inbetween the lines, I think it is something beyond his control for the consumption rate as long as the MAF is clean, the TPS is clean, and the plugs and leads/coils are good.

[Woodchip Lurker Find all posts View Profile Close Woodchip]

I have little understanding of how a lpg system on a prado would go together now but i do know that on my old v8 ford lpgas system that the inlet air was restricted in flow considerably for the engine to run on gas. I am wondering wether there is a restricter in the newer systems as mine was vacuum operated and if the vacuum hose was blocked or inoperative the engine would run terribly and chew gas horribly.
Gas would be good if you dont intend to travel with your vehicle but is very hard to get remotely. There is little chance of getting gas in remote areas and you cant cart it like petrol in a jerry can. I used to have to plan my journeys in the old Ford around where you could get gas in the Territory and it was few and far between.

[croozza Avid PP Poster! Find all posts View Profile Close croozza]

I have little understanding of how a lpg system on a prado would go together now but i do know that on my old v8 ford lpgas system that the inlet air was restricted in flow considerably for the engine to run on gas. I am wondering wether there is a restricter in the newer systems as mine was vacuum operated and if the vacuum hose was blocked or inoperative the engine would run terribly and chew gas horribly.
Gas would be good if you dont intend to travel with your vehicle but is very hard to get remotely. There is little chance of getting gas in remote areas and you cant cart it like petrol in a jerry can. I used to have to plan my journeys in the old Ford around where you could get gas in the Territory and it was few and far between.

LPG is more accessable now in remote areas (usually only on the main roads), however I'm not a fan of losing the rear fuel tank, I know you used to be able to get scoober style tanks that can fit on the other side of the other tank, that would be the system I would go for. The newer LPG systems are completely different to the one you would have had, so dare I say there would be no restrictor.

[marknatasha89 Lurker Find all posts View Profile Close marknatasha89]

LPG sensitivity

I hear you. My petrol economy was around 15l/100 around town, and once dipped below 11 on a highway run with lots of 80km/h roadworks zones. When I converted to LPG (converter into airbox, as opposed to direct injection), I achieved 446km on 75 litres (supposed to be 72 usable litres, but I let it idle on empty for the last couple of k's) on a typical 110km/h run with a moderate load. I just recorded 350km out of 70l, ie 20l/100 around town on weekends, ie no traffic jams.
My thoughts are to:
1. Wind in the sensitivity screw on the converter to limit the gas flow. This should be the larger of the two adjustment screws, the other being idle mixture. With the engine idling, wind the sensitivity in until the engine starts to hesitate, then wind it back out 1/4 turn. Then similarly for the gas flow screw on the gas pipe between the converter and air box.
2. Revert the muffler flap 'performance mod'. I've heard LPG needs a good flowing exhaust, but when cruising at low revs, perhaps the flap does provide better back pressure, thus economy.

I'll let you know how these affect my '99 3.4 v6 manuel in a couple of weeks.

I drove from Brisbane to Darwin to Uluru and back in a thirsty old Hilux in 2003 on LPG all the way. On the highway there was no further than about 250km between LPG stations. Sure you don't expect LPG off the highways, but the mighty 90 still should offer good range between the secondary petrol and LPG tanks.