90s LPG 3.4 or diesel. that is the q.....

[Steve M Addicted PP Member Find all posts View Profile Close Steve M]

You must have been gentle with the old girl Esses, my neighbour accross the road use to have a hiace and the motor lasted for god knows how many klms but he was always doing rear diffs. He is a carpenter and had it loaded with all his saws, drills etc and then the roofrack chockers with building material as well, hes now got an 08 D4D hilux single cab with an alloy tray on it, so far he's had no issues with it..............Cheers Steve

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

Dunno about gentle:-). Bought it new in '91. Ran out the first 20 000km then put LPG on it. It carried everything from envelopes to truck batteries, stationery & bulk water. Also did about a dozen moves with it for friends & family. At one stage I was "seeing" a girl who lived in Penrith, so every Friday night straight after work off we'd shoot from Canberra to Penrith & back again on Sunday night.
Anyway, back on subject. I'd definitely be sticking with the V6 & "Gassing" it. But that's just me.

Oh & the WORST engine ever for converting to LPG would be the old Mitsubishi 3.0 V6. They used to overheat & crack the valve-collets, drop a valve & BOOM the engine.

[Gozz Lurker Find all posts View Profile Close Gozz]

Just converted my 3.4 to LPG & it's all good so far. It's the older mixer system & all I can say is that it's vastly improved on older systems I've had. If there's a drop in power, I can't pick it & even with gas at 73.9 cpl it's still halved my running costs. This is my 9th LPG vehicle & I think I'll always lean this way. The 2.7 being unsuitable for gas comes as a surprise to me as I had it's fore-runner - the 1RZ 2.4 - in my LPG Hiace & it did 300 000km before slightly cracking the head. Welded up & good until 428 000km when the poor ol thing just plain wore out. 2nd motor was still going at 699 000km when sold.

Hi Esses.
I own a 4.5lt nissan patrol thats on lpg but am looking at buying a 90 series 3.4lt V6 auto and converting it to lpg like you did.
My patrol is a fantastic car but just lacks torque for towing my boat which is approx 1,5 ton.
Do you feel the 3.4lt auto on lpg would tow this amount of weight up through the hill going to Eden .
Also can I ask how much the conversion cost and what km you get now.
Thanks heaps.

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

Hi Esses.
I own a 4.5lt nissan patrol thats on lpg but am looking at buying a 90 series 3.4lt V6 auto and converting it to lpg like you did.
My patrol is a fantastic car but just lacks torque for towing my boat which is approx 1,5 ton.
Do you feel the 3.4lt auto on lpg would tow this amount of weight up through the hill going to Eden .
Also can I ask how much the conversion cost and what km you get now.
Thanks heaps.

In a word - no. I came from a 4.2 LPG GQ Patrol Wagon to the Prado & while on paper the Prado has about the same torque as the ol' GQ, in the real world the GQ did have more grunt down low. Gearing could play a part in that too though the Patrol was heavier of course. Your GU should have more torque again. Is there a noticeable difference in performance between ULP & LPG in your 'trol? These days there shouldn't be much diff., if at all. It was JUST discernible in the GQ.

The conversion cost $3500-00 & I'm getting around 350 km from 68 litres of LPG. Roughly 16 mpg down from 21 mpg on ULP. Happy so far but I'd be looking at improving the performance in your 'trol first if you're towing regularly.

[Gozz Lurker Find all posts View Profile Close Gozz]

Thanks mate.
My GU would eat my old GQ in torque and speed and my GU is auto.
I've been looking into my cars gas system and it seems to be totally wrong for my car.
The system is very reliable but not the right size for a motor this size.
I'm looking at converting my standard system to a vapor system which should restore the power to it's former (power) glory like it was before I had it fitted with gas.

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

Hi Esses.
I own a 4.5lt nissan patrol thats on lpg but am looking at buying a 90 series 3.4lt V6 auto and converting it to lpg like you did.
My patrol is a fantastic car but just lacks torque for towing my boat which is approx 1,5 ton.
Do you feel the 3.4lt auto on lpg would tow this amount of weight up through the hill going to Eden .
Also can I ask how much the conversion cost and what km you get now.
Thanks heaps.

The Prado will do that easy, but so should the Pootrol, Personally, I would forget about going to LPG (just for towing) on anything but a V8. With the Prodo on LPG you will loose the rear tank in all the normal installations unless you go for a custom set up. So that is another reason not to do it.

[Steve M Addicted PP Member Find all posts View Profile Close Steve M]

I wouldn't go LPG for towing, it will use a shit load more LPG and probably work out dearer then just running petrol. I had LPG on my 90 and for me was the worst thng I ever did. Yes its definatelty cheaper running around town but you lose a huge amount of touring range (this may not bother you) but when I used the LPG for towing or using on sand/beach (anywhere where heavy accelerating was required) the gas usage was approx 3 times the amount then when just normal driving. I had issues with it stalling under heavy breaking, petrol fumes on hot days (another common issue as others on here with LPG have had the same issue on the 90's) You can have the LPG tank fitted in the rear cargo area which allows you to keep both petrol tanks but if cargo area is of a main concern then this may not suit you. Just my opinion on the LPG. Plenty of people running it and love it but I dont like it and wont have it again.......maybe if it was factory fitted ?? maybe.......................Cheers Steve

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

Thanks mate.
My GU would eat my old GQ in torque and speed and my GU is auto.
I've been looking into my cars gas system and it seems to be totally wrong for my car.
The system is very reliable but not the right size for a motor this size.
I'm looking at converting my standard system to a vapor system which should restore the power to it's former (power) glory like it was before I had it fitted with gas.

Something not right then. We had our Territory converted to Vapour Injection recently & can't speak highly enough of it. Absolutely seamless transition between ULP & LPG & no power loss at all. Steve M, yes you lose touring range if you only run LPG (I'm getting 400km from my LPG cylinder) but if you use the belly petrol tank as well then overall touring range is about 1000km still. Lotsa places you still can't get LPG, after all.

[rthy Lurker Find all posts View Profile Close rthy]

Had similar issues with my b2600 when off roading and lpg, would distory the 70lt of gas, lasted 200kms! lucky the 75lt petrol lasted the rest of the off road trip and some. not to mention the airbox exploded afew times and gas leaks :S
Loving the 159lts of petrol!

Would have thought a 4.5lt patrol (on petrol) would tow better than the 5vzfe?

[Steve M Addicted PP Member Find all posts View Profile Close Steve M]

Hi there Esses, no way I ever got 1000k from the reserve tank and the LPG, the most I got from the LPG was just on 350 (63L 59 useable) and the reserve tank 69L 500k and that was sucking fumes I reckon. And this was all freeway driving so if off road I reckon would have been only 2/3's of that 850. And currently the price of LPG at some outer towns is so bloody expensive then you have higher usage (L per 100k) its really not worth the hassle. If running round town then definately works out cheaper but towing etc I found to be extremely thirsty and this was supposidly tuned 100% which realistically isnt possible when running duel fuel. I had a couple of backfires which luckily didnt damage anything just sounds like a bomb going off under the bonnet lol. I believe the new injection systems, liquid etc are suppose to be heaps better but when I had the gas fitted the old venturi system was the only thing available for the 90, not sure if that has changed, the 120 V6 you can only use injection due to plastic inlet manifold as it cant handle the extra heat from the LPG venturi style. Cheers Steve

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

Know what you mean about back-firing. Had that a lot in my old L300 4WD Van, a little in the Hiace & a little in the Patrol. Had the choice with the Prado of the Mixer System @ $3500-00 or Vapour Injection as in our Territory for an extra $1000-00. The installer (who did our Patrol & Territory) actually recommended the Mixer as he didn't think that the Injection gave enough benefits to outweigh the extra cost on the Prado. I've got to say that this is the best Mixer setup I've had out've 8 different vehicles (9 counting the Territory), if there's a power drop, I can't pick it.
I think a lot of your fuel consumption problems might be traced to yours being an automatic. Mine's a manual (all my 4WDs have been) & was doing a steady 21mpg around town on petrol & 16mpg on LPG. I'd expect around 24mpg on the highway which would give an easy 1000km from both tanks. Not as good as the 2 petrol tanks of course, but still not bad. With my Patrol you'd SCRAPE 750km out've 90l of LPG & 73l of petrol:sad:! FABULOUS 4WD, but VERY thirsty!

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

[QUOTE=Esses;336611 Not as good as the 2 petrol tanks of course, but still not bad. With my Patrol you'd SCRAPE 750km out've 90l of LPG & 73l of petrol! FABULOUS 4WD, but VERY thirsty![/QUOTE]

That just about sums up LPG v's Petrol then....
You can pay thousands of dollars to get an LPG fuel system that is not as good!!!

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

That just about sums up LPG v's Petrol then....
You can pay thousands of dollars to get an LPG fuel system that is not as good!!!

Oy Vay! "Not as good". Where do you get THAT rationale from? Using LPG is ALL about running costs (I'm quite happy to admit) & depending on where you are by using LPG you drop your day-to-day fuel cost by around HALF. No, you don't get as good an economy-rate, nor range either unless you fit 2 or more cylinders, simply because Gas just doesn't have as much energy as petrol per litre/kg or whatever. But it is CHEAP compared to petrol (especially 95 & 98) & diesel. This debate has been had many times over on the Patrol Forum & when you do the Maths the running costs (fuel only) always come out: Petrol - WAAAY most expensive; Diesel - a lot cheaper; LPG a little cheaper again. That's not factoring in comparitive servicing costs at all which generally go: Diesel dearest, Petrol & LPG pretty line-ball. That's also been my experience with all of my work-vans.

I suppose that "Not as good" also refers to power & performance. Well, the "old-fashioned" Mixer-System on my Prado isn't giving anything away to the original petrol that I can feel - I've only been driving professionally for 28 years so I THINK that I can gauge vehicle performance - & our Territory with Vapour Injection is better again. If you go for LIQUID LPG Injection, it makes MORE power than ULP (202kw vs 192kw in the Ford 6) though still has poorer economy than petrol.

Still don't believe me? Best ask every Taxi-owner in Australia then, or Courier Owner-Driver. Maybe they're all wrong too.

[marknatasha89 Lurker Find all posts View Profile Close marknatasha89]

LPG holy debate

Indeed I only bought my 3.4 petrol as an ideal candidate for LPG and I was right. Why?
1. The 90 series petrol was cheaper to convert than a falcon wagon (at my installer), due to the factory easy dual petrol setup, spare out of the way, etc - easy.
2. I drove a single tank of LPG from Raymond Terrace (near Newcastle) to Canberra last year - 446km on 72 usable litres. I reckon I can improve on that since winding the gas flow screw in 1/2 a turn, plus if driving less than 110km/h. At this rate, I am certain I can budget for a 1000km range, eg from Winton to Alice via the Plenty. Sure, I will use more LPG on the soft stuff, but I didn't notice additional consumption with a FULL car and roofrack on the sand last weekend. No worries with torque.
3. Towing is still a breeze and my consumption was still around 18l/100km towing a 7x5 trailer with a cage full of dirt.
4. Sure they warn of valve recession, but I run Flashlube and intend checking the clearances regularly (next on the to do list). Still, LPG engines are known to go longer and certainly run cleaner. Taxi engines are often known to do 500 000km between rebuilds.
5. Having an entirely separate fuel system provides excellent risk mitigation due to problems on trips, plus is handy for problem diagnosis.
6. Aside from the easy cost justification (conservative 30 000km estimate by my calculations), one is producing way less CO2 than ULP, and especially diesel per litre, albeit at higher consumption. Definitely a well tuned LPG system should pollute less overall: http://www.motorpoint.com.au/LPG-Better-Environment.asp and http://people.exeter.ac.uk/TWDavies/...om%20fuels.htm. Apparently they exclude charging LPG vehicles from London's congestion tax due to their low emissions!
7. Less fumes! I was very conscious of stinking out the garage starting on petrol with its rich auto-choke. Apparently my 90 still starts on petrol, then immediately switches itself to LPG. There is far less smell, and less toxic as above.

[rthy Lurker Find all posts View Profile Close rthy]

Depends on the application and person really, LPG has its Pro's and Con's just like the other fuels.
There are a few quirks that makes lpg "not as good" as petrol, such has loss of boot space (not so bad in 4x4's), loss of power (and more so near empty) with the older mixer setup, shorter range, extra weight of 2 tanks (for dualfuel), longer fill up time, availability in remote areas, wax build up in the converter, intake detonation, greater chance to explode and so on.
(For the record, I have experienced all these quirks, LOL, lpg bypass valve started to leak due to over fill - error on my part)

On that note LPG has come along way with the gas injection tech (ie. new LPI falcoons) but still lacks factory support from overseas manufacturers.
Also LPG price has gone up thanks to the new LPG Tax and demand in the past few year but still cheaper than petrol.