80 lpg

[Sharky71]

hi ive got an 80series just put it on gas getting pretty bad mileage just wondering if anyone with an 80 could give me a comparison on how many ks to litres to give me an idea whether mines normal? thanks.

[fixa4377]

hey mate, i got an 80 very similar set up tires, bars, roof racks ect and mine fills about 100litres on a normal re fill and i get 475kms - 500kms country driving unloaded, about 450 kms country loaded with gear and 425 around town, its a manual 4.5litre 93 model, whats your numbers??

[Sharky71]

gday thanks for the reply mine is a 94 4.5litre auto it fills 92-95 litres for that i get 260-270km city/highway, 310ish loaded highway about 350 unloaded highway and thats running it out. I reckon i should be getting better than that? gee i wish i got your mileage, i've been told the valve clearances need doing i wonder whether that could be my problem?

[roscoFJ73]

gday thanks for the reply mine is a 94 4.5litre auto it fills 92-95 litres for that i get 260-270km city/highway, 310ish loaded highway about 350 unloaded highway and thats running it out. I reckon i should be getting better than that? gee i wish i got your mileage, i've been told the valve clearances need doing i wonder whether that could be my problem?

Lets see 2.70 divided by 95 litres is 35lts per 100klms. Holy cowshit Batman ,that is heavy:eek:

[Sharky71]

your not kidding i cant believe it either, i didnt think it would use that much considering its been dynoed!.

[Flying Briar]

your not kidding i cant believe it either, i didnt think it would use that much considering its been dynoed!.

I've owned a few gas powered vehicles over the years and am about to get my FJ62 converted. A few years back I was running a straight gas 4.2ltr V8 holden 1 tonner, fitted with IMPCO gear and HEI ignition. I started fiddling with the mixture as I thought it was running way too rich (by the smell of the pipe). I leaned it off to what was acceptable with a sniffer tester. With an 80ltr tank I got as far as the Lake George turn off to Canberra from Sydney. The vehicle was empty and I kept to 110km/h. I rang up a mate in Sydney to find out why it was so thirsty and he said that I made it too lean. A symptom was it did lack a little bit of power and that in order to maintain power & speed I had to drive it harder, hence use more gas (That was his explanation). Therefore I adjusted the mixture screw and richened it up. On the way home I sat on 120km'h and managed 20 mpg. That was my experience.

With late model cars with computers a piggy back gas computer is fitted and switches on when the vehicle is required to operate on gas. Some fuel injected vehicles start on a few pulses of petrol before auto switching to gas. I would ask a LPG mechanic to check your oxygen sensor as this can stuff with mixtures and if you've lost a little / fair bit of power, check that your catalytic converter hasn't collapsed. Due to the computer tuning on duel fuels, when oxygen sensors play up they will dump rich fuel loads that will help burn the guts out of your catylitic converter. Hence ruin your economy. Hope this helps!

[Sharky71]

thanks for the advice i have to get valve clearances done first then it goes back on the dyno i will speak to them about what ya said.cheers

[minisman]

I.ve been chasing problems with my poor running lpg system for ages now, and FB is right, an engine tuned lean will use more LPG. When i first got my ute i was getting at least 400k from 70l, then the head gasket blew and after fixing that the timing was out which made it backfire and burn a couple of the carby gaskets.
So it was sucking air through these gaskets making it run lean. While i was driving it like this I was usually out of gas b4 300k. I've since fixed the leaks and get about 350, but its still not perfect, I still have timing issues.

Any LPG gurus in here that can help me trouble shoot my problems?

[bloke76]

my brother gets about 300km out of his 80series on lpg 85-90L.
i get similar, about 330km out of my 100series, i was getting around 400 until i added a roofrack, suspension, and 33in muddies.

from most people i have spoken to most 4.5 petrols get between 3 and 5 km per litre on lpg

[goose]

I've gat a 96 gxl which I put an IMPCO system on with a 120l (90 usable tank). With the HT 275/75/16's, standard suspension and no foof racks or anything I'd get about 350k town or close to 400k hyway out of a tank. I've got 285/75/16 cooper st's on now so I'm not sure if I'm gunna get better or worsre milage yet.

Fixa, 475 to 500 k's a tank seems extremly good. What sort of system are you running?

[Flying Briar]

I've gat a 96 gxl which I put an IMPCO system on with a 120l (90 usable tank). With the HT 275/75/16's, standard suspension and no foof racks or anything I'd get about 350k town or close to 400k hyway out of a tank. I've got 285/75/16 cooper st's on now so I'm not sure if I'm gunna get better or worsre milage yet.

Fixa, 475 to 500 k's a tank seems extremly good. What sort of system are you running?

My Dad had Mum's multi point EB Falcon converted to gas about 6 months ago. The car's economy has turned to crap in the last few months. He's doing 30ltrs to 100Kms in town. His mate who is a gas mechanic (he didn't fit the unit)is coming around this week to check it out. I'll let you know his verdict. We're suspecting the oxygen sensor. Taking all bets!?

[Sharky71]

I.ve been chasing problems with my poor running lpg system for ages now, and FB is right, an engine tuned lean will use more LPG. When i first got my ute i was getting at least 400k from 70l, then the head gasket blew and after fixing that the timing was out which made it backfire and burn a couple of the carby gaskets.
So it was sucking air through these gaskets making it run lean. While i was driving it like this I was usually out of gas b4 300k. I've since fixed the leaks and get about 350, but its still not perfect, I still have timing issues.

Any LPG gurus in here that can help me trouble shoot my problems?

sorry for late reply been queensland 5 days i have had valve clearances done and new (under warranty) mixer fitted, aparently it has to be put back on dyno so i am told to retune it so i will do that and see what happens:crazy:

[Sharky71]

my brother gets about 300km out of his 80series on lpg 85-90L.
i get similar, about 330km out of my 100series, i was getting around 400 until i added a roofrack, suspension, and 33in muddies.

from most people i have spoken to most 4.5 petrols get between 3 and 5 km per litre on lpg

sorry for late reply, well going on that maybe mine is about average (not happy) my brother has 95mdl 80 5 speed and he gets consistantly 440-480km out of 90litres maybe he got a gem?

[Sharky71]

I've gat a 96 gxl which I put an IMPCO system on with a 120l (90 usable tank). With the HT 275/75/16's, standard suspension and no foof racks or anything I'd get about 350k town or close to 400k hyway out of a tank. I've got 285/75/16 cooper st's on now so I'm not sure if I'm gunna get better or worsre milage yet.

Fixa, 475 to 500 k's a tank seems extremly good. What sort of system are you running?

sorry for late reply, i am running 275/75/16 a/t tyres 2' lift, full roofrack a few people have said to me that would contribute to poor economy i guess i just expected(hoped) to get around 350 to 400 out of 95 useable litres cheers

[Sharky71]

My Dad had Mum's multi point EB Falcon converted to gas about 6 months ago. The car's economy has turned to crap in the last few months. He's doing 30ltrs to 100Kms in town. His mate who is a gas mechanic (he didn't fit the unit)is coming around this week to check it out. I'll let you know his verdict. We're suspecting the oxygen sensor. Taking all bets!?

mine was doing 33-34 to 100 ive had the valve clearances done so i will have it dynoed again and see what happens keep ya posted on outcome! does anyone know how you test an oxygen sensor?

[Flying Briar]

mine was doing 33-34 to 100 ive had the valve clearances done so i will have it dynoed again and see what happens keep ya posted on outcome! does anyone know how you test an oxygen sensor?
Steve, What brand of LPG system are you running? My gas mechanic said that you usually test O2 sensors with a voltmeter but he say's that the Toyota ones are usually ok. Refer to engine manual for factory voltage level.

[Sharky71]

Steve, What brand of LPG system are you running? My gas mechanic said that you usually test O2 sensors with a voltmeter but he say's that the Toyota ones are usually ok. Refer to engine manual for factory voltage level.

gday mine is impco approx 4 months old i have to say that i have been less than impressed with it or the economy side of it.It runs terrific on both fuels, starts instantly hot or cold, i have had some dramas with it since it was put on (thankfully warranty covers it) maybe i was wishfull thinking expecting 350-400 out of a tank,it has to go back on dyno so i will get them to test O2 sensor cheers steve

[Flying Briar]

gday mine is impco approx 4 months old i have to say that i have been less than impressed with it or the economy side of it.It runs terrific on both fuels, starts instantly hot or cold, i have had some dramas with it since it was put on (thankfully warranty covers it) maybe i was wishfull thinking expecting 350-400 out of a tank,it has to go back on dyno so i will get them to test O2 sensor cheers steve

I assume you're running Dual Fuel ? If so what is your economy on petrol ?

[Sharky71]

I assume you're running Dual Fuel ? If so what is your economy on petrol ?

I am running dual fuel 95litres useable gas and 95 litres petrol, On petrol i get approx 400-450ks out of tank. Both tanks probably about 670-700ks approx, Not real flash for 180 odd litres of fuel i think!

[fixa4377]

the most i have ever got was 489 kms unloaded country driving, and i switched over to pet before it ran out so i had a little more to go, im running an IMPCO system too, but i do get 110 litres out of it at some times on filling, but im still very happy with that, it works out to about $11 per 100 kms, loaded up with camping gear ect, like i said its closer to the 425 mark , and running air con kills the fuel! like by 10% atleast! i had my valve clearences done and it improved a little, you do need to get them done,,

[fixa4377]

i didnt think you dyno'd gas for the tuning????

[Flying Briar]

I am running dual fuel 95litres useable gas and 95 litres petrol, On petrol i get approx 400-450ks out of tank. Both tanks probably about 670-700ks approx, Not real flash for 180 odd litres of fuel i think!

I can only suggest one thing for the time being and that's to bump up the timing to around 10 - 12 degrees advance. I'm not famillar with the 4.5ltr engine but if it has a distributor adjust the timing and run it on gas only. Put the timing back to standard when you switch to petrol. My 1 tonner use to run 12 degrees advance and it was great. Good economy and great power. The only one other thing and it's illegal - punch out the guts of your catalytic converter. Mate, it makes Commodores run well!

[Sharky71]

the most i have ever got was 489 kms unloaded country driving, and i switched over to pet before it ran out so i had a little more to go, im running an IMPCO system too, but i do get 110 litres out of it at some times on filling, but im still very happy with that, it works out to about $11 per 100 kms, loaded up with camping gear ect, like i said its closer to the 425 mark , and running air con kills the fuel! like by 10% atleast! i had my valve clearences done and it improved a little, you do need to get them done,,

I have had clearances done just need to get it re tuned and i guess will see how it goes then, it would be nice to get 400-450ks loaded up on highway, i'll just have to wait and see i guess.

[Sharky71]

I can only suggest one thing for the time being and that's to bump up the timing to around 10 - 12 degrees advance. I'm not famillar with the 4.5ltr engine but if it has a distributor adjust the timing and run it on gas only. Put the timing back to standard when you switch to petrol. My 1 tonner use to run 12 degrees advance and it was great. Good economy and great power. The only one other thing and it's illegal - punch out the guts of your catalytic converter. Mate, it makes Commodores run well!

I will keep that in mind Cheers Steve

[Sharky71]

i didnt think you dyno'd gas for the tuning????

I dont know, just what they have been telling me they've been doing

[Emo]

Around town I get about 300km's out of 90 litres which is around 30l/100km's. I'm running 285/75/16 BFG M/T's and I've got a reasonable amount of extra weight (steel bullbar, storage drawer, fridge etc). On a trip the economy gets heaps better. Lightly loaded I can get over 400km's out of 90 litres.

[Sharky71]

Around town I get about 300km's out of 90 litres which is around 30l/100km's. I'm running 285/75/16 BFG M/T's and I've got a reasonable amount of extra weight (steel bullbar, storage drawer, fridge etc). On a trip the economy gets heaps better. Lightly loaded I can get over 400km's out of 90 litres.

there is such a variance as to what people get, i know everybody drives different but i certainly dont drive mine like a sports car, maybe i should it might be better.

[Flying Briar]

there is such a variance as to what people get, i know everybody drives different but i certainly dont drive mine like a sports car, maybe i should it might be better.

Steve, I've had a bit of a re-think on this one mate and we should compare oranges with apples and see if we can balance up the equation. As an indicator, A VP 5.0ltr fuel injected Commodore does 600-700km on 80ltrs (Gas/Highway).On Dual fuel it weighs in at about 1800kg, the vehicle is the standard police pack, lowered 15 x 6 rims, 4spd Auto. Now consider your 80 series, vehicle weight ?, Height off the ground / wind resistance ? Tyre width / resistance ? Your Cruisers total restrictions will no doubt affect your consumption, so say we add your handicap to the Commodore's figures and for argument's sake take 250kms off, you should be still getting at least 400km from a tank. Here's a brief check list for you to ask your gas installer. 1: Check your O2 sensor (as your petrol economy on the freeway isn't that great either), 2:Check that your catalytic converter hasn't collapsed. (This will affect both gas / petrol economy.You can test this by getting under the vehicle and hitting it with your hand. If you can hear and feel loose stuff rattling around inside, then a good chance it is cactus) 3: How's your airfilter and is it blocked? (Did they fit a new one for you?) 4: Are you getting 95ltrs in your tank ? (some tank valves can play up and the filler may blow off but your only getting 70ltrs in!). 5: Does the gas mechanic really know what the ignition / timing system is set for and how it works? ( If he's experienced, he will give you a decent technical answer). I tend to agree with the last member. All of my gas vehicles have never been on a dyno. A gas analyser up the exhaust was all that was ever required to tune it!

[Sharky71]

Steve, I've had a bit of a re-think on this one mate and we should compare oranges with apples and see if we can balance up the equation. As an indicator, A VP 5.0ltr fuel injected Commodore does 600-700km on 80ltrs (Gas/Highway).On Dual fuel it weighs in at about 1800kg, the vehicle is the standard police pack, lowered 15 x 6 rims, 4spd Auto. Now consider your 80 series, vehicle weight ?, Height off the ground / wind resistance ? Tyre width / resistance ? Your Cruisers total restrictions will no doubt affect your consumption, so say we add your handicap to the Commodore's figures and for argument's sake take 250kms off, you should be still getting at least 400km from a tank. Here's a brief check list for you to ask your gas installer. 1: Check your O2 sensor (as your petrol economy on the freeway isn't that great either), 2:Check that your catalytic converter hasn't collapsed. (This will affect both gas / petrol economy.You can test this by getting under the vehicle and hitting it with your hand. If you can hear and feel loose stuff rattling around inside, then a good chance it is cactus) 3: How's your airfilter and is it blocked? (Did they fit a new one for you?) 4: Are you getting 95ltrs in your tank ? (some tank valves can play up and the filler may blow off but your only getting 70ltrs in!). 5: Does the gas mechanic really know what the ignition / timing system is set for and how it works? ( If he's experienced, he will give you a decent technical answer). I tend to agree with the last member. All of my gas vehicles have never been on a dyno. A gas analyser up the exhaust was all that was ever required to tune it!

Gday my vehicle probably weighs fairly heavy as it has few extras, it has 2' lift and a roofrack which would'nt help, but i did take the rack of at one stage to see whether it made a differance but it was minimal, i am running 275/70 bfg A/T on back and 275/70 Silverstone A/T on front running about 40 psi in them. I checked cat and it seems ok, i am crook at the moment so i have'nt had a chance to get O2 sensor checked but i will do. The air filter was changed, the tank seems to take between 90-95litres from when it starts to run out. The conversion was done by one of best gas specialist in melbourne, and to my knowledge they dyno all of them. Because its under warranty i am a little hesitant taking elsewhere so not to void it, because i have had it back a few times already for varias problems.I think it will take me a while to find whats wrong hopefully will get there in the end. Cheers appreciate advice Steve

[Sharky71]

I finally got around to getting stuff done
VALVE CLEARANCES DONE
RETUNED THIS TIME WITH MOBILE UP THE EXHUAST ANALISER
O2 SENSOR CHECK DONE
CAT CHECK DONE
TIMING WAS ON 3 DEGREES IS NOW ON 8 (on his advise)
I have cracked the 300k mark but is on empty maybe 20-30km to go? Whats disapointing is most of that was freeway:crazy: :crazy: I will see how the next few tanks go. I do have a crack in the front muffler would that effect it?
Cheers Steve