LPG on the yamaha V8 engine - XC90
 

Does anyone have positive experience of using LPG on the Yamaha V8 engine, as fitted to the 4.4 V8 XC90, and I believe the S80? I've just bought an XC90 with this engine.

I'm really looking for someone who has done 30k miles plus without problems with valves or valve seating. I have spoken to some of the bigger name suppliers, and none have direct experience. But it seems such an obvious conversion, I would have thought someone would have done it. I'm happy to spend the money, but not if I'll end up with big bills to fix the head.

Andrew H.

Lpg
 

Ask classicswede , He would know how to help .
Regards
Mike B

Will send you details via email later today.

Hi, new to this forum but here goes, I've just done the same and bought an xc90 4.4. On a 07 plate 44k, so far there appears to be a few problems in converting to LPG first one being the tank under the boot, you will probably only get a 80l tank filling to 60l giving a range of approximately 180 miles. Next as you rightly say not many people have done this and there is a question wether or not the valve seats are going to be affected by wear, I have spoken to Prins over this and he told me that he hadn't personally fitted one to this engine but the Japanese engines seam to work closer to the heat limits of the valve seats but if you fit flash lube there shouldn't be a problem. The car is going in to be looked at on Saturday, if you find out anything more please post it as it might help me to, I will let you know how I get on

Would you just check with them that the "Heat limits of the valve seats are what causes the problems with the Jap engines or if there is something more complicated than that"??

Also worth asking them if they know how flashlube stops the valve/seat from wearing/burning. Micro welding is what produces VSR

Will ask them on Sat, but in the mean time do you have any more info that might help me to decide wether or not it's a good or bad idea, Thanks
I was chatting on the phone to a company in the Netherlands today that use a direct liquid injection system that I was interested in, as there is some talk of introducing the fuel in this way lowers the temperature, but this is not quite right, it is used to keep direct fuel injected engine injectors cool (Audi vw fsi) and so on, so as the conversation went on, it was this company as well as the chap from Prins that suggested using flash lube as he said that petrol has components with in it to protect the valves and LPG doesn't . Flash lube is supposed to do the job by coating the valves seats much like lead did in leaded fuel.

Flashlube does help with VSR but does not cure it in all cases.

The liquid injection does have some advantages and it should help with cooling the cylinders and valves but I don't think this will help much with engines that suffer from VSR. The early liquid injection systems had lots of problems and i suspect that the latest systems are also likely to suffer with fuel pump failure. I'm going to keep staying with vapour systems for quite some time yet but am watching the progress with the Liquid systems.

There are a number of factors that can cause VSR. Have a read of this link and it does cover most of the issues and is not a million miles of teh mark. I don't normaly agree with this guy but what he done here s not far off just with a couple of things missed off
http://www.ibadesign.info/LPG/VSR.pdf
What he says about the valve acting as a hammer is a chunk of where the problem lies but he has missed off a factor that is the make or break.

Lean burning is a well know problem amongest installers in the know. UKLPG have a list of engines that suffer with VSR on LPG. The problem with the list is that most of the info comes from two system suppliers, one has very poor fuel control and in the early days major injector failure and the other does have slight issues that with some engines will cause VSR due to leaning. A lot the problems will also come down poor installation. A good example is the 4.7 V8 jeep is on the list. There are 1000's of these converted with the common good systems and they are perfectly fine without any valve care.

I do not claim to fully understand VSR but I have a good idea and the reasons do vary from one engine to another.



The answer to the volvo 4.4 v8 is I do not think they will be a problem but the one I did I fitted with a valve saver system as I could not get enough data on the materials used in the engine and the details of the valve events.

I would keep to top quality parts and fit a valve saver system as insurance.

Damage caused by lean burning will not be resolved by any valve care products

i have lpg fitted to my discovery 3. took a long time to take the plunge as it has soft valve seats - after 60k reports of loss of seals.

i think a lot is as stated to do with poor mixture - too lean most often. This often causes the check light (MIL) to come on. I had it with a previous D3 that i converted. I have now got the latest system that is connected to the OBDII and reads the adaptation setting so the LPG computer readjusts the mixture before the MIL comes on. Not had 1 MIL light since fitting it.
I also chose the option with the system i have to run the petrol injectors together with the gas one. petrol is only open for a millisecond or so - but this adds petrol all the time - gives the petrol pump to do keeps the injectors and petrol side working - and i hope protects the valves.
to be sure i also added a v-lube system that adds a lubricant via the LPG low pressure line. this is then mixed with gas and added via the gas injector. much more accurate than the flashlube

So far so good - but i would say its well worth getting the car set up on a rolling road. i find there are still spots in the LPG map that are out and give the car too much or too little gas. it takes a good installer some time on the road to modify the map to ensure its 100% - but well worth it

One other issue with the xc90 v8 is the high fuel pressure warning - this needs an emulator to trick the ecu that all is ok. without it the check light can come on (and will) and also from time to time the ecu will need resetting

r
ian

Thank you CLassicwede and hids4u, it's not often you can chat with people that have an informed and intelligent view on this subject, all to often people post hearsay and focus on problems but loose sight of the fact most if not all of these can be overcome, taking me on to the lean burning of LPG , or rather the control of the LPG that hids4u has chated about, in both of your views which one of the manufactures have the best control of the fuel and why?
P.S. CLassicwede that link was really good!!!!

The ford engine fitted to the land rover is well know for VSR problems. There are uprated heads available for them and that does help.

We actualy remap the petrol ecu as the petrol map is part of the problem on the range rover sport especialy.

The fuel pressure issue will not be solved with an emaulator.

The fuel control is a mixture of the system and the installer.

As to what systems have problems and which ones are best I would rather discuss via phone or email.

The main issue is the installer. Here is a list of many of the popular mistakes that I see from other installers including many that are supposed to be teh best.
1) poorly adjusted map and wrong settings in the ECU.
2) injector nozzles mounted half way up the inlet manifold
3) wrong type/size injectors fitted
4) vaccume line T'd into an existing line or tapped into a single runner in teh manifold.
5) Y joing on V engines fitted wrongly starving one bank of fuel

That is just the sort of mistakes that cause running problems, there are many more that I see that would be considered unsafe like poorly secured tanks and fuel lines held to the brake lines with zip ties!

The biggest consideration should be the installer then the kit.

Sorry for late reply

I agree with previous comments - a good system badly installed or set up poorly

I would suggest SEB or BRC

Make sure you get one with the OBDII connection and someone that will really set up the MAP properly - ideally I think this should be done on a rolling road.

Let us know if you take the plunge

regards
Ian

Volvo V8 LPG conversion. Has anyone done it?
 

Hi Welder,

Could you, please, let us know whether you converted your motor to LPG or whether you decided against it. It would be very interesting to find out.

Many thanks in advance,

Is high fuel pressure really the issue
 

Hi Classicswede,

I converted 3 Volvos in the past and 2 of them did not have petrol return lines. 60k and 70k miles later no MILs due to high fuel pressure have been noted.

I'd appreciate if you could elaborate on this a bit more, please.Are V8 models equipped with a different fuel pump? Why would not emulator fix the issue?

Thank you.

Yes they are fitted with an dumb pump. It needs to see the correct amount of fuel flow. The emulators dont send the right signal at the right time.

Are you an installer or just DIY?

Thank you for the lightning fast reply, Classicswede!

No, I am not an installer these days, but used to work in a garage a while back. Well, long habits die hard and I am still doing LPG conversions on all our family vehicles. I did get officially trained in LPG conversions just for insurance purposes for the period between the time when a conversion takes place and the moment when my vehicle get inspected and the appropriate certificate gets issued.

Coming back to the Volvo V8 conversion, I am glad I found this thread with some very useful information as I've purchased S80 V8 recently. I've had a look and there are a few challenges with this vehicle, but they are not critical. Some points are listed below:

1) There seems to be sufficient space for a vaporizer to be placed at a lower level just in front of the air filter. I believe this is the place where an auxiliary engine preheater should be. Not plenty, but there is sufficient amount of space to put either Magic 3 (350bhp) or Prins (335bhp) vaporizer there.

2) I totally agree with you that some installers put the injector nozzles half way up the inlet manifold and this is not ideal at all. The problem with this engine is that one can insert the nozzles very close to the head(s), however, connecting them to the injector rails becomes virtually impossible. The front bank is ok because there are openings between the individual inlet ducts, BUT the rear bank does not have these openings and, therefore, the connecting hoses will be very long for the rear bank, because they will have to be fed through the LH side of the engine. This is not acceptable.

One possible solution to this problem would be the placement of the individual LPG injectors in the direct proximity of the petrol injectors i.e. underneath of the upper part of the inlet manifold. There is very limited space there and I think the only injectors that can fit there in almost vertical upright position are the magic injectors because they have got the feed inlet from the side and not from the top.

Do you happen to know any other individual injectors that have a very good performance regardless of their orientation? It would be great if the lpg injectors could be placed horizontally.

Another question that I have is whether you know or not about any injectors that can be mounted directly onto the manifold without a separate nozzle and a hose that elongate the whole assembly quite a bit? I know that AG and Autogas Italia used to make them in the past 5-7 years ago but I could not find anything of that kind in the market these days.

I would be very grateful if you could suggest a solution to the high pressure issue in the petrol line.

Million thanks in advance,
Cheers

Hi Classicswede,

Could you, please, PM me your email and/or phone number so that I can get in touch with you. The website does not allow me to send you a PM because my number of posts is below 30.

Cheers,

Contact details sent

From what I read and heard when I was looking into LPG converting my V70R a few years ago, it's no surprise to me that there are significant reliability problems associated with LPG installations, but very few of them are the fault of the technology...rather how it's applied.

Ian said it should ideally be set up on a rolling road...I say it's essential. You're replacing the fuel system, and some of the suggestions I heard ("Just set it at idle...it'll be OK") were flat-out scary.

cheers

James

A lot installers do only set the system up on idle and totaly rely on the OBD connection adjusting the fueling to the correct position. They do not even drive it at all!

You don't need a rolling road but you do need to drive it and take live data from teh OBD port to ensure the fuel trims are within tolerance and it does drive as it should. The cars fuel system is still in control and adjusts the mix as it wants it while in closed loop for pre wide band sensor cars.

Fair point, Dai...what I meant was that monitoring AFRs on-load is essential. That's perfectly possible on-road with the right kit...it's exactly how we (petrol) mapped the 740 Turbo.

The trouble with pre-wideband cars is that you have no idea what the car is doing on full load unless you add a wideband (in the tailpipe, or better still via a bung in the downpipe). Assuming the ECU has it sorted it risky, in my experience. The Landi system I had had an RPM vs Load map which would need adjusting with the aid of a wideband. Obviously that's not an issue for something more modern (like the XC90) with a factory-installed wideband.

cheers

James

The other key thing is fully understand how the map works and making sure you do not have any holes in the map. It is those holes that will create the big problems.

Options for injector & nozzle placement
 

Hello gentlemen,

I have been away for the best part of the month and did not have time to convert my S80 V8 yet.

While I was away I was searching through the net and found this:

http://www.bigastech.com/rootsgis/Sc...4S_LPG_ENG.pdf

It does not seem to be neat and I, personally, don't like 25-35cm runners and then having further 20-25cm of convoluted manifold duct i.e nearly half a metre for a gas to pass from injector to cylinder with half of this 'journey' being in a premixed state. However, such arrangement makes conversion much easier without a need to take off petrol rail & the bottom part of the manifold. I guess, it would have been neater to put individual injectors on each or the ducts.

Last weekend I took the upper part of the inlet manifold off just to see where would be the best places to drill the lower manifold. Not too much space here and there are a few alternatives. They are as follows:

1) Drill the wholes and install injectors directly between the lower and upper parts of the manifold. I completely agree with Dai that in such case one needs to go for extremely reliable LPG injectors. However, the space is tight there and the only way to make this option to work is by using 90 degree bent lpg hoses. Any attempt to bend a 12mm (6mm - i.d.) lpg pipe can collapse it.
There are silicone hoses with 90 and 135 degree tight bends, but I have never used silicone hoses for lpg and will not do this unless I am completely sure that they are lpg-friendly. Any advice on their compatibility is greatly appreaciated? The upstream hoses need to be fed through the gap openings at the front(left) bank

2) Drill the holes in the lower part of the manifold and feed the lpg hoses through the gap openings at the front(left) bank. A couple of the injector rails need to be located outside the front bank and connected to the lpg hoses.

The same problem as in (1): to keep the length of lpg hoses more or less equal one needs to use 90 degree hose bends so that the runners to the rear bank are not twice as long as the ones leading to the front bank.

3) Connect individual injectors to the ducts at the upper part of the inlet manifold as shown in the link above. The use of individual injectors will allow me to use 4-5 cm connecting hoses instead of 25-30cm thus reducing the length between the injectors and the inlet valves.

Problem: a substantial part of the manifold will be filled with the premixed gas and there might be a risk of backfire.

Not entirely sure which option is best.

I noticed that there are quick-fit connectors on the market where there is special connector got installed between the engine and a petrol injector. The gas is being fed through this connector too. This is a very neat solution, but unfortunately, on this particular engine, injectors on the front and rear bank are not parallel to each other. Plus there is a fair bit of a problem with the petrol injector rail being pressed against the upper part of the inlet manifold.
Shame, so I need to choose from the 3 options above.

Another Bigas bodge conversion!

The instructions are very poor and do not show you all that has been done or what is needed.

If you look at the photos they have actualy fitted straws into the manifold so the point of injection should be nearly in the right place. They are showing that you need to advance the injection firing order. Now doing it manualy on a V engine is going to cause you problems and if injection advance is needed there there is a problem with install on this type of engine.

To keep the pipe lengths reasonable then individual injectors and straws might be the best bet. There is no need for the petrol addition unless doing that instead of using a valve saver system.

Again a ECU memory reset should not be needed but with the setup they have there the fuel trims will have been drifting and causing restart problems without the ECU reset.

In fairness those instructions were made in 2007 and most systems have moved on a lot since then.



The silicon pipe will take gas but it is not fuel safe so should not be used. PTFE or Nylon pipe can be used as per the manifold straws.

Hi, I am new at this forum and have the same problem. My car is XC90 V8 and has the high pressure issue, the light comes on and after some time I have to reset the ECU (disconnecting the battery) because the car stops and doesn't start. After resseting everything works fine (but the light).

Did you find any solution to this issue? My installer here in Spain does not find anything to solve it after 4 months and I am worried.

Thanks in advance.

A fuel return line is the only solution that works every time

Hello . I have Volvo XC90 2010 V8 with LPG but i have a problem . We cant figure out the right mixture , can you send me the LPG Map for V8 XC90 with the correct mixture ?
Thank you !

I did see your visitor post but for some reason would not allow a reply.

No use sending you a MAP as 1) most likely you are not using the same ECU. 2) your injectors /vapouriser etc are also unlikely to be the same and 3rd if the point of injection is not the same the map will not work and 4th even two cars with identical engines, LPG components and all fitted the same will have optimum maps that differ from each other.

More than happy to look a photos of your install and config files and advise

[QUOTE=Welder;1155473I have spoken to Prins over this and he told me that he hadn't personally fitted one to this engine [/QUOTE]

I have the aforementioned car with the LPG conversion.
It's a 2007, the car was first owned by Prinz and it has had there LPG conversion on from new.
It's currently done 84000k with no issues regarding engine.

duel fuel
 

When doing these gas conversions on the Yamaha V8 engine is it still possible to have the option of keeping the engine on petrol as well, with a simple switch between the two. I am thinking of moving the five back seats out to make room for more fuel storage although I have no idea if that is feasible or even if it would be legal! but it would make the long hauls between towns/citys out here a bit easier
Thanks

You have to keep the petrol there.

1) the engine needs to start on petrol
2) should you run out of LPG you have petrol backup
3) the engine ECU needs to see correct petrol pressure in the fuel rail

Thanks for that C S

Thanks this maybe usefull as I had a high pump fuel pressure failure, I'm not sure if related.

For record - I have two 2007 XC90 4.4 V8 one with Prins LPG & one without.
(Idea to do both once I know the reliability etc)

I have yet to use LPG car much yet. I took 6,7th seat out one tank there and another under the spare wheel to increase range.

So far it seems to work well. Apart from the fuel pump issue. (now fixed but unfort thieves broke into yard and stole Cat converters on 6 cars incl mine)

Great Chat group. I'll report as things go..

Thanks for your info .. on fuel return line. I wonder if thats my issue.

I'll report back.

BTW Do you have XC90 LPG 4.4 V8?

Is it a Prins 2 system ?

How you enjoying it?

Anyone else have XC90 / 80 same engine with Prins?

Extra Fuel Tanks
 

I took out 6,7 seat and put a tank in there. I raised floor slightly.

Unfortunately only after did I find another solution for cylinder tanks about 800mm long and 180mm / 200mm diameter.

My guess is four or maybe five of these would be a better solution.

Not lose much boot space.

Hi Nice

Do you still have the above mentioned car ?

Best Rgds
Bruce