Discovery 3.9 on LPG only??

[Bosvark]

Hi, Guys, hope you can help/guide me in the right direction.....

I have already got some info on the improvement on the heads, torque/power, so I need guidance on the LPG side of things now, please

A bit of back ground info:
I have a 3.9 V8 Discovery which Im using for off-roading and pulling a 3T trailer during the week.
Im looking in cost effective ways to increase the torque . I want to improve the torque band , ideally from Idle to 3000rpm.

I was wondering if I use a Intake manifold from a 4.0/4.6 Thor V8 which has slightly longer runners instead of a plenum chamber, will that give me the torque from lower rpm, and is it possible to fit above mentioned intake to a 3.9?
I will use the throttle boby that match the Thor intake. ( or one from a MG ZT v8)or do I need to get a larger flapper intake and AFM?

If the above modifications are possible, will I be able to run on LPG only?
If so, can the injector holes in the intake manifold be used to plumb the LPG injectors in too?
I understand that the petrol injectors can not handle the higher pressure needed to inject the LPG, is the other injectors that can be used?
And using a propper injector, will that improve the power and efficiency ?

What other mods do I need to do just to run on LPG?
Is it a case of remove all petrol injection, efi, injector rail and plumb in LPG kit?

Regards
Bosvark

[bodger]

the best way to run JUST lpg is to use an early FLAPPER manifold and then all you need to do is remove all the injection stuff and weld up the injector holes .. with this manifold you can also still use the EXTRA AIR VALVE , as it not only uses electric to work it but also heat from the manifold too ..so the wires can be disconncected from that too ....

then as far as LPG is concerned all you need is a mixer on the plenum ..and you can get rid of the AFM ...

i know all thsi because i did it , but the only concern i had if i ever ran out of fuel ( LPG) there is no way you can refill on the side of the road !

so i changed back to dual fuel just in case .....

[Bosvark]

Hi,
I just found this lpg kit on e-bay, its been used on a 5.7Lt v8.
Tartarini ETAGAS LPG injection kit 5.7 V8 Marine boat
Item number: 250641265369

Will this be any good for my application???

[Bosvark]

Hi, Guys

I've done some searching but can't fid any thing specific on what to use and what to remove(not needed any more) when convert to run on gas only.

Will it be better to use a multi point sequensial syst or a single point syst.
Am I wright saying you need a syst with its own ecu, lamda , temp , air sensors.

And things to remove: AFM, injection rail and harness, inlet stepper motor


Regrds

[ChrisJC]

First point is that I would buy a kit that is suitable for your engine. I have tried mixing & matching bits from LPG kits before, with limited success.
I currently run two LPG V8's, both 4.6:
1. Land Rover, LPG only, an OMVL kit I got from Chris Perfect Components. It does have carbs and will run on petrol, but it doesn't do so very often. The LPG kit is analogous to a carburettor system. No sensor or clever 'lectrics. Works very well. 'Keep It Simple'
2. Range Rover, LPG & Petrol. This is a very nice OMVL Dream 21 system, that piggybacks onto the existing petrol system. The car starts on petrol then switches over when its ready. It's completely seamless, you can't tell when it changes.

I don't know if you can get a 'stand alone' LPG only injection system, the injection ones piggyback onto the existing petrol ECU, which means that everything on those must be present and working.

Both systems work very well, I'm pleased with them both. They're at different ends of the spectrum though.

Chris.

[Bosvark]

The way I see it is, when it run on lpg it act as a stand alone syst any way. The LPG ecu must get its signals/inputs from the likes of the Lamda , coolant temp, AFM sensors So if all of the above are connected into the lpg ecu, thn it should run in the same way ase the 14cxu ecu.
Or am I way of the mark here...??

[ChrisJC]

The LPG system I have (OMVL Dream XXI) measures the pulses going to the petrol injectors, and uses them to calculate pulses for the LPG injectors. The petrol ECU thinks the engine is running on petrol, but actually the petrol signals are being open-circuited by the LPG ECU which is putting in LPG instead.
It does also measure LPG pressure and water temperature.
Therefore the petrol injection system must be complete and working correctly for the LPG system to work.

Chris.

[Bosvark]

Hi, all me again

I've got myself a complete PRINS sequensual System from ebay

Does any one have a wiring diagram for it?
How do I know if this vaporiser is good for 250+ BHP?

Any info/help welcome

[Bosvark]

Hi

I've got the LPG kit sorted now, will start to install it tomorrow.

I was just wondering if there is any improvements/tweaking to do on the intake manifold and plenuim before I put it on.

I've fitted new spark plugs and a set of genuine land rover ignition leads and king lead.

Cheers

[bodger]

for get the std leads if your running LPG they will last no time at all ..
have a look here : http://www.vehicle-wiring-products.eu/V ... mepage.php

get your self a roll of copper core wire and just pull the ends off your old leads and solder them on the new wire , even genuine leads won't last more than 6 months ..
when i ran them as soon as it rained or even damp misty day the leads shorted out on LPG , but a made a set what 2 years ago now , must be and no problem since , and it dosn't interfere with the radio ...