The Big Dog's On Lpg

[Alex JB]

Hi,

The system starts on petrol and cuts over to gas providing the engine coolants hot enough and once the revs go over 2.5k

this means letting it idle for 30 secs on cool summer morings then bliping the throttle. In winter I imagine (and I do some cold mornings already) drive for 1/2 mile then blip or drive over 2.5k rpm, the changeover occurs on the way down the revs, this avoids changing when under load.

Yes the kit was fitted in Warington Cheshire, a stone's throw from that dodgy nightclub by the big roundabout.

PM me if you want there number, they have a website to.

[dibsLPG]

Wow!

Took a look at your link and that's real data that no one can argue with.

9.3Euro / 100 Km LPG

14.5Euro / 100Km petrol

LPG = 64% of cost of running petrol.

Thanks for the info :)

Congrats and welcome to the Lexus LPG team.

That was a bargin price on the fit at £895 even if it was a single point. Which i too have installed on my Lesus is200 and I would recommend the Flash Lube kit. It acts like a lubricant to the top end of the engine and keeps the valves lubricated and cooler. Well worth the price for the kit and you can buy it off eBay (search it under Flash Lube) for around £50.00

your engine management light come on from time to time but i think it fine (common problem with LPG cars)its usually telling you that the Fuel system if confussed (or that's what it tells me on mine).

Happy motoring and saving the environemnt: :winky:

Dibslpg

[Skraggy_uk]

Hi,

The system starts on petrol and cuts over to gas providing the engine coolants hot enough and once the revs go over 2.5k

this means letting it idle for 30 secs on cool summer morings then bliping the throttle. In winter I imagine (and I do some cold mornings already) drive for 1/2 mile then blip or drive over 2.5k rpm, the changeover occurs on the way down the revs, this avoids changing when under load.

Yes the kit was fitted in Warington Cheshire, a stone's throw from that dodgy nightclub by the big roundabout.

PM me if you want there number, they have a website to.

Yeah the asddress/website would be good. Were they on Riverside business park/trading estate behind some shops?

[Haylands]

Hi all

I worked for a LPGA approved garage for about 18mths fitting single point and multi point on all sorts of cars from a 3 cylinder Matiz to a 12 cylinder Jag and just about everything in between....

I do not know everything about lpg and others on here may know a lot more, from my limited experience and a general interest I have found out / noted the following, I'm putting it on here to help others make the decision...... lpg or not????

A few Facts about LPG

It has a lower calorific value than petrol but an octane rating of about 110

It burns hotter than petrol

It produces no acid in the ignition process

It will give you better emissions then petrol (if set up correctly)

An Lpg tank is virtually impossible to damage enough to cause an explosion, a controlled release and ignition into a flamethrower yes, but the pressure in the tank is too great to allow oxygen back inside to create an explosion

Now there are two basic types of installation,

Single point

Multi point or injection

Both systems introduce Lpg in its gas state into the engine instead of petrol (Ford tried with a liquid LPG injection system but it didn't work very well)

The basic or single point system involves a tank with a pipe to a vaporiser which turns the liquid Lpg into gas, this is then fed to a mixer which lets the gas into the engine, with this the amount of lpg let into the engine is controlled by a stepper motor in a closed loop system, this takes a reading from the lambda sensor and then adjusts the mixture accordingly, this is the type most commonly used (there is a system for early cars with no Lambda but they are few and far between now)

Multi point injection system, uses a tank and pipe to a vaporiser which then feeds gas to an injector for each cylinder, this is controlled by a separate ECU that "steals" info from the cars ECU, adjusts the gas injector opening time accordingly (you need the injector open for longer to get more gas in than petrol because of the reduction in calorific value). The system also monitors the Lambdas and adjusts the mixture with them as well.

A properly set up injection system will have no reduction in power over petrol but will use approx 15-20% more Lpg than petrol, the emissions will be better with less C02 being released, indeed you could even remove the cats and still pass the latest emission tests (but this is not allowed).

Most Injection systems start on petrol then swap over to Lpg after a short time, this is usually done at a certain temperature

Contrary to popular myth this has nothing to do with a car not working on lpg when cold, this stems from early systems with poor vaporisers that could not vaporise the lpg unless they were very hot, I ran a Range Rover V8 for several years that ONLY used LPG, it started on LPG at -10c with no problems....

The reason the systems start on petrol is to give the petrol system something to do, the early days saw cars run for 1000's of miles just on lpg, then the driver ran out and switched over to petrol only to find nothing happened as the petrol system had stayed dormant for so long it was all seized up!!!!

Now most injection systems that are SET UP PROPERLY will not have much of a detrimental effect on engines

Most single point systems will damage an engine unless they are set up right.

I saw lots of single point systems on cars where they had been set very rich to get the system to run because of badly matched parts, the vaporiser has to be big enough to cope with the demands of the engine.... ie the bigger the engine, the bigger the vaporiser that is needed, the mixer is very critical to each engine as well. It is easy to get a car to run on lpg, the trick is to get it to run right.

Most cheap single point systems will work but they will flood lpg into the engine and cause a rich mixture, this creates excess emissions and will damage the engine. If you have a single point system get the emissions checked, this will give a good indication of the quality of system/instalation. Interestingly a friend who has an MOT garage always checks emissions on duel fuel cars on petrol because "they all run rich on LPG don't they"

Lpg, being gas, is a dry mixture and does very little lubrication, I would always have a Flash Lube system fitted as it can't do any harm (just check it gives 5 drops per minute at tick over with a warm engine)

Lpg does not like running with platinum spark plugs, it can give misfires, although I did run a Voyager 3.3 with platinum plugs for 15000 miles with no problems....

The engine oil does not get very dirty when running on LPG as there are minimal acids and other nasties from the combustion process, this does not mean you can change the oil less, it is still getting bashed to bits by the engine and wears out just as quick, it just stays looking better.....

So go for it if you do loads of miles but make sure you get a well matched, well installed system especially if it is single point...

Oh and before anyone asks no I haven't got it on my LS430 I know what’s involved in fitting it and I know how many original wires are cut and spliced and I don't want to reduce the reliability of my car..... most engine running faults on cars with LPG are down to ingress of water or wires chaffing from the original install and I bought a Lexus because I wanted reliability as well as a nice car....

Pete

[Alex JB]

Crikey Pete!

You are the man in the know!

The guy who fitted my kit had exactly the same kit on his soarer for may years without problems and this was one of the reasons I went with them.

There was a Co2 test done during set up and is attached to my instalation document.

I thin the original Mk1 LS ia 250g/km or so, with LPG my car is now at 119g/km, that's the same as peugeots latest HDI's that they rave about.

I take your point about the electrical system, If I could afford a 430 I'd be concerned about chopping into the harness but I'm at the other end of LS ownership costs and it was a risk I was prepared to take.

over the 4000+ miles I have done I have saved around 500quid on fuel and the kit is making the car worth 400 quid or so more = if I sell te car tomorow, it's paid for itself already.

I recently did a longish trip with the cruise on at less then 70 (when it was chucking it down las sat), I got 255 miles out of 20 quid of gas, that's the equivalent of 48mpg in current petrol prices!

Pete's info is great and I think we are a lucky forum to have such involved people with good information and level heads.

I say go for it.

Pete says choose wisely.

Is there anyone with a nightmare story?

[v8rick]

hello fella`s although i dont run my lexus on lpg i do run my rangerover 4.6hse on it with no problems at all , a couple of things that may be useful to lexus owners however , when i first bought my rangerover it was running on a single point system this type of system is a bit dated technology wise , especially for the hi tech management systems on modern cars today .

my previous rangerover was a 1994 lse model and that ran fantastic on a single point system , my latest one is a 1998 p38a model and, whilst it ran on lpg it was nowhere near as nice to drive as it was on petrol so, i upgraded the system to a sequential ( multipoint system ) and the difference is incredible both from an economy point of veiw as well as performance.

although have been a hgv mechanic for almost 40yrs fitting the lpg kit is , in my opinion quite a simple diy operation , as long as it is done in a tidy and competent manner , i dont and never have used flash lube and never had any trouble as far as reliability is concerned bearing in mind the rover/ buick v8 is not a patch on the refined lexus v8.

the down side of a single point system is that the mixer acts as a restricter in the induction manifold thus slightly reducing performance , the multipoint system does not use a mixer the gas is ecu controlled thus no or very little noticable power loss , the rangerovers i have owned run even better on lpg than they do on petrol , from an economy point of veiw they cant be beaten they have saved me a fortune !.

as for reliability with the exception of the ill matched singlepoint system that used to be fitted to my latest rangerover i have found them totally reliable and no trouble whatsoever , i bought my kit from a company called tinley tech down in cambridge who , i cant praise highly enough , they were great and offered loads of advice .

i knpw that the rangerover and the ls 400/430 are 2 completly different animals but, they are similar in the fact that they are both powerfull v8 vehicles so the basics of both are similar as regards running them on lpg i hope this may help someone out there who is trying to decide whether or not to run thier car on lpg , finally i have to say that for the bit extra it costs i would definately choose the multipoint system for a lexus , if you have experianced both you would agree i am sure.

rick

[AKY-B]

Hi guys.very interesting to hear from different people and their views on lpg.my personal opinion is that if u have a 430 go for the sequential system.it will pay for itself both in economy(I GET 40-46MPG IN "money terms") and in in the sheer smoothness of the system.very little difference in the perfomance between lpg and petrol-negligible loss of power on gas ,but big fuel saving.ps i drive for a living and do 60k a year.i hope this makes thing a little clearer but everyone has their own opinion!!!

[race890]

I picked her back up yesterday with one shiny new LPG kit fitted. :D

Cost 30quid in petrol to drive up there. 17/18 mpg (nailing it then bad traffic on M6) = 24p / mile

Cost 14quid in gas to drive back. 17/18mpg (what do you expect with the cruise control set at 110) = 12.7p / mile

HOORAH!

Hi, You guys in the UK & Europe are more advanced than us re LPG; as we have 'less' urgency to use it as our petrol prices are a bit lower.

What brand & model of LPG system did you have fitted to your LS400 ? I understand that a sequential injected LPG system does not operate in sequential mode on a car that does not have true sequential fuel injection ECU; meaning that many earlier toyota EFI systems are grouped injection (so 4 injector fire together, then the other 4 etc) vs true sequntial where the 8 injectors fire at separate times. An LPG installer told me that grouped injection engines on LPG, will have a much higher risk of backfire & not run as smoothly because the LPGas is 'sitting around for longer (more micro-seconds) in the inlet manifold for longer before being used. I would like your feedback re: how your system has gone for you & what type, brand, model of LPG system it is. For those looking to LPG a LS430; seq-gas-in is best as the 430 has a true seq (8 injectors fire all at independent times, not in groups of 4's) efi system.Thanks in advance Andrew (email- invest1234@gmail.com) Australia.

[Haylands]

Hi, You guys in the UK & Europe are more advanced than us re LPG; as we have 'less' urgency to use it as our petrol prices are a bit lower.

What brand & model of LPG system did you have fitted to your LS400 ? I understand that a sequential injected LPG system does not operate in sequential mode on a car that does not have true sequential fuel injection ECU; meaning that many earlier toyota EFI systems are grouped injection (so 4 injector fire together, then the other 4 etc) vs true sequntial where the 8 injectors fire at separate times. An LPG installer told me that grouped injection engines on LPG, will have a much higher risk of backfire & not run as smoothly because the LPGas is 'sitting around for longer (more micro-seconds) in the inlet manifold for longer before being used. I would like your feedback re: how your system has gone for you & what type, brand, model of LPG system it is. For those looking to LPG a LS430; seq-gas-in is best as the 430 has a true seq (8 injectors fire all at independent times, not in groups of 4's) efi system.Thanks in advance Andrew (email- invest1234@gmail.com) Australia.

Hi

What’s up, given up on the LS430 or LX470?

Fitting a multi point to the earlier 400 is not a problem, you will not get backfires, the amount of gas sat in the inlet manifold at the wrong time is so small with an injection conversion that it is negligible. A single point will leave more in the inlet manifold but at the end of the day it is the car that makes the difference.... The famous Rover V8 has a good reputation for blowing up air boxes on single point LPG that is because it is let into the inlet manifold about 2ft from the valves and because the engine has a marginal ignition circuit so when it is not kept in tip top condition the spark is weak and fires late so when the valve opens to let more mixture in, the mixture inside is still on fire and ignites the mixture in the inlet manifold...

The Lexus is far better made and of better quality, keep it regularly serviced and don't just run it when it’s poorly and it will be fine.

If I had a 400 I would have no problem in running it on a properly set up single point system, they work fine with it, yes there will be a slight loss of power, but how often do you drive flat out.... you will only notice the drop in power on traffic light racing and you didn't buy a Lexus for that (although I have to admit they will embarrass a lot of cars from the lights) So pay your money and take your pick

AS I HAVE SAID BEFORE JUST MAKE SURE IT'S SET UP PROPERLY..... This is the major reason for people complaining about LPG cars

Good Luck with whatever you get

Pete

[Leigh2000]

Hi Pete

I was looking for the original post you made about having the lpg fitted to your car but couldn't find it.

Anyway, I need some advice. My lexus started misfiring on a couple of cylinders in August and despite taking it into the shop (not the original fitters, they're in Milton Keynes and I'm in Peterborough) it hasn't been fixed. There aren't any error messages being thrown up by the diagnostic and it only hapens on lpg. I've taken to just driving around on petrol but not ideal obviously and I want it sorted. The guy who I took it to says that it's a probelm related to where the lpg ecu has been ftted, which is just behind the bumper. He says he looked for somwhere else to mount the ecu but that is the only place he could see to put it. As aresult of being put here the thing filled up with water. He said the ecu itself wasn't damaged but that the water may have been interfering with the connections. He did dry it out and it was Ok for a week or so and started missing again. Again, no problem on petrol.

Another lpg specialist I spoke to said it might be a probelm with the coil packs, although a dagnostic did not turn this up as a problem. I'm told the coil packs are fairly bullet proof anyway.

I'm going to book it in again for about three weeks but what do you think? Is your ecu mouned in the same place or can you suggest a better alternative? What are the chances of me needing a new ecu and how much would that be!?

Anyway- I'd really appreciate it if you'd let me know what you think.

Leigh

[Haylands]

Hi Pete

I was looking for the original post you made about having the lpg fitted to your car but couldn't find it.

Anyway, I need some advice. My lexus started misfiring on a couple of cylinders in August and despite taking it into the shop (not the original fitters, they're in Milton Keynes and I'm in Peterborough) it hasn't been fixed. There aren't any error messages being thrown up by the diagnostic and it only hapens on lpg. I've taken to just driving around on petrol but not ideal obviously and I want it sorted. The guy who I took it to says that it's a probelm related to where the lpg ecu has been ftted, which is just behind the bumper. He says he looked for somwhere else to mount the ecu but that is the only place he could see to put it. As aresult of being put here the thing filled up with water. He said the ecu itself wasn't damaged but that the water may have been interfering with the connections. He did dry it out and it was Ok for a week or so and started missing again. Again, no problem on petrol.

Another lpg specialist I spoke to said it might be a probelm with the coil packs, although a dagnostic did not turn this up as a problem. I'm told the coil packs are fairly bullet proof anyway.

I'm going to book it in again for about three weeks but what do you think? Is your ecu mouned in the same place or can you suggest a better alternative? What are the chances of me needing a new ecu and how much would that be!?

Anyway- I'd really appreciate it if you'd let me know what you think.

Leigh

PM sent

[ManicMark]

I picked her back up yesterday with one shiny new LPG kit fitted. :D

Cost 30quid in petrol to drive up there. 17/18 mpg (nailing it then bad traffic on M6) = 24p / mile

Cost 14quid in gas to drive back. 17/18mpg (what do you expect with the cruise control set at 110) = 12.7p / mile

HOORAH!

I'm sure 'POST' rules don't forbid you mentioning WHERE/WHO did the work, and cost? We could get a bulk discount.....

I'm sure I could drive without a spare tyre.....and may be driving to Cyprus later in year, so.....(can you GET gas in Turkey?)

Hello Chris they are very big on gas in Turkey, if you drive through Greece not a chance, fill up in Italy ta Mark