end kits (electronics) and Mixer.
Including: Emissions feedback loop, Principal of Computed &
reactive LPG Fuel supply to engine management (Lambda and throttle
position sensor driven).
The Lambda (In your exhaust) acts as a lean/over-rich sensor,
and sends appropriate voltages to the LPG ECU to be computed,
along with throttle position and reaction information from
the throttle position sensor (TPS). We prefer to add an additional
one as we find it difficult to rely upon the original aged
|Sorry no picture
available as yet.
||Emulators are there to trick the vehicle's
original ECU (EFi Models only) into thinking it is still firing
the injectors. It also prevents the ECU from getting upset
and going into default.
|LPG computer ECU (making the appropriate
calculations). Whilst reliable info from the Lambda and TPS
may be assumed, the accuracy of the ECU software brand means
its (broad range) calculating abilities may be an issue. Some
software types allow quite a range of adjustments to allow
for large variations in vehicle type and use (as ours does),
and others just rely on the 'Right for one, Right for all'
way of thinking. This is why we have called to issue some
of the most popular systems in favour of one that we now have
fuller control of.
B. Stepper motor
In-line stepper motor (the slave device restricting or de-restricting
LPG flow to the engine) Lambda TPS & ECU loop ) Quite
simply, a restricting / de-restricting device (stepper motor
driven) in the LPG fuel delivery line controlled by the LPG
ECU, that is in turn provided with information from the TPS
and Lambda probe. It is normally possible to adjust the base
setting of these devices.
Throttle Pot Sensor (measuring throttle position and reaction),
sited on the plenum chamber is a std. Rover fitment.
Along with the Lambda sensor above, the 'TPS' sends information
to the LPG ECU, which in turn makes appropriate calculations
on engine emission values, so that the stepper motor can restrict
or de-restrict LPG flow to the engine.
|Sorry no picture just yet.
Basic Principal of LPG Fuel supply to engine (vaporizer).
The vaporizer works by having 'equal' atmospheric
pressure on either side of it, one side being the feed pipe to the
mixer (the bit on your intake) and the other side being a hole in
the back of the vaporizer body. If you look, you can see and even
touch the diaphragm. It only needs tiny changes in pressure to affect
it (touch or air pressure). It's actually the same in principal
as a demand valve worn by Divers.
How it delivers. Engine induction pressure rises on one side only
( the mixer side) and causes more LPG flow through it. That's basically
how it meters the fuel at engine start up, idle and as RPM increases).
||Mounting the vaporizer (A), in this instance
to a Discovery. Make sure it is firmly bolted and is not in
the path of fan wash (air pressure generated by the coolant
fans), otherwise it may fail to operate effectively.
|Connecting the water cooling pipes (A&B) to the vaporizer.
They are essential to maintain operational temperature in
Possible over-sight problems; If unit is assumed to be in
good working order while set up with the vehicle static in
a workshop, it's not unknown for it to be mounted in a position
where, under-bonnet air flow or air pressure (affected by
coolant fans etc) will cause the diaphragm to work in a biased
fashion due to the extra air pressure. Also affected when
out on the road, and even as the bonnet is closed.
||Here you can see the other end of the water
pipes have been 'Teed' (A&B) into the available engine
coolant hoses. It is important to make sure good coolant flow
will still be achieved in the original system.
|It is now possible to see that the vaporizer
(B) is securely mounted well out of the way of fan wash, you
can also see the 'emulators' (A) mounted in the most convenient
spot on this model.
This Unique (and invisible) LPG active mixer for the Rover
V8 up to 4.6 Litre, when using the Weber, Edelbrock or Holley
4-Barrel carb system.
Shown with the lid off.
Shown with the "Active Vacuum"
This unique Active Mixer, offers the essential part-closed
Air intake for LPG running, with automatic vacuum-operated
plenum control for unrestricted air-flow, essential for petrol
performance, all within the small profile 12in air filter
||Active Mixer for LPG with Weber and Holley
4 barrel carbs
(up to 500cfm)
|Top view of this unique
||We don't need this one :-)
Side view of the bigger Chevy type system. You can
see this would present some difficulty with bonnet clearance
issues on UK spec. cars.
The problem with the Rover V8 EFi engines (mostly) pre-1990 (flapper
type) is easily resolved using our unique Flap opener. Controlled
by a small vacuum pump (supplied but not shown) this device will
automatically open the Air Meter flap, giving far better throttle
response and alleviating the need to use a blow-back valve in line
to protect from backfire.
Why lose power & efficiency & risk great expense involving
a new Air flow meter if ignored? (In some cases even a blow-back
valve can't save it.) See below.
This nasty little device is the best most people can come
up with to protect the air flow meter, you will see, above
that we don't use it.
forget to return to our main LPG Pages 'click'