GU 2001 3.0 Diesel - lpg injection safe/reliable?

[Wreno]

Hey everyone

I bought my patrol a year ago now and it has a lpg injection kit installed. Previous owner liked it as he did some caravan trips.

My mechanic cautioned me about using it a while ago so am unsure whether to use it. He mentioned that if the regulator or control valve fails it can take out the engine. anyone else running this on the 3.0L patrol?

Are there concerns around using lpg injection knowing there are some concerns with engine reliability already?

Previous owner also replaced the engine, not sure of cause though.

Interested to hear what others have experienced. A couple of other threads here seems to indicate ppl who have them do like them and are happy to use them (seems mostly in 4.2 though)

Thanks for ur help

Cheers

[Bigcol]

I think you may have to change your mechanic..................

he sounds like he knows sod all

if the regulator fails...... NO gas can get through
if the control Valve fails.......NO gas can get through

they have a "double jeopardy" with these systems, either DGas or Diesel Gas
if there is an electrical "spike" - the systems shuts off
if a valve fails - the system shuts off

you need to take it to someone who fits and services the Gas systems to get a better idea of them


as a side line, I have asked many many times, what is the percentage of blown 3.0L to how many sold

no one has ever told me

I think they are an ok motor myself

[threedogs]

I'd be ripping it out the mighty ZD30 is frail at the best of times.
Its only a 3 ltr so its never gunna be a rocket. Plus now you're
paying for two fuels. I was tempted when this first appeared but no
way would I put gas on a ZD30, for what.?

[Wreno]

Thanks for the replies.

Bigcol, it sounds like the protections are built into the system already through the valve system you mentioned, so that is reassuring. Mechanic seems good in other areas, he prob just repeating what he has heard etc

Yep as its a 3.0l am not expecting it as much of a performance gain, but better efficiency and a bit more power. Might use it on long trips or towing only.

Muffler upgrade next so will focus on that now :)

[4bye4]

I am a licensed gas fitter but on air cooled motors - not autos. I would be very surprised if you got a performance gain, I would think that same or slightly less would be more usual.
LPG makes a motor run a bit hotter and as there is no lubrication in LPG (gas is dry). If your motor is worn it may hasten its demise, but will not cause a failure if it is correctly fitted.
It's a good idea to do more frequent oil changes as LPG does produce some nasty oxides, but Diesel oil will pick these up. That is why in a petrol engine its a good idea to use a gas oil when converting. That's kind of basic as there is a fair bit of chemistry involved which I can't remember.
In a nutshell, if its fitted I would use it but would probably not convert an old motor to dual fuel.

[Bigcol]

with the diesel gas and or Dgas installations, it improves the revving of the engine and assists in fuel consumption

using my 4.2 as an example...............
with the gas turned off, it rev's to 3000rpm, and I get about (not a true figure, as I cannot completely remember) 13L/100k
1st - 15kms
2nd - 30kms
3rd - 45kms
4th - 60kms
drop it into 5th

with the gas turned on, I get (this IS accurate, as I keep checking it) 12.5L/100k (with diesel & gas total kms divided by total fuel brought in Ltrs)
the engine freely rev's to 3500rpm
1st - 20kms
2nd - 35kms
3rd - 55kms
4th - 80kms
drop it into 5th, and it will go 110+

when I drive with the gas OFF - engine temp sits at 95*
when I drive with the gas ON - engine temps sits at 85-90*

yes, gas burns faster and hotter - 110% burn, but it is a weak "explosion" - especially in an engine with a compression like a diesel

as long as the injector pump has been tuned correctly for the gas (ie: fuel turned down) to allow the extra fuel being feed into the engine - the gas
the gas then helps the diesel to burn & create the power
helping the engine to rev freely
burn all of the fuel in the cylinder (instead of a guesstimated 85%)
so the engine becomes more efficient

[Wreno]

I do see a slight gain and the revs and power increases. So when cruising and without altering the accelerator, u can flick the gas on and the engine picks up enough that i can reduce fuel slightly to maintain speed.

Improving that fuel burn rate, as mentioned by bigcol and in other threads, should result in some performance gain but mostly better fuel economy.

So if I can sum up the comments:
* Only slight improvements in a 3.0 so you would not fit it generally if you're looking for a mod
* safe to use if fitted correctly. Valves will cut iff supply if they fail.
* Replace oil more frequently to help remove anything left behind by gas process.

Thanks everyone!! Been great learning more about this system

Cheers :)

[threedogs]

Wonder how a re-mapped CRD would go against a diesel/gas CRD.[twotrolfam]
Col mentions they turn down the fuel pump for the gas, so with out gas how does it perform
Or maybe Col can answer, I've only heard good with 4.2TD conversions to diesel/gas