|
|
Ford Scorpio 2.9 Cosworth LPG Conversion
By Stephen Shaw
The filler Nozzle
The filler, I decided to mount on the bumper. The position I chose was
easily assessable from underneath the car. The 8mm copper tubing was run from
the vent pipe, through the petrol tank straps to the filler point. I also placed
a few short pieces of rubber pipe over the tubing to buffer against sharp edges.
Vaporiser
Converts the liquid propane to a gas
The vaporiser I placed directly onto the inner wing by the suspension strut.
There was a pre-drilled hole here which needed widening. With a washer behind
the unit and a lock washer under the nut it was bolted up from inside the wing.
Both of the cars heater pipes (situated behind the engine) had to be connected
to the vaporiser using the supplied T adapters and hoses. This was an awkward
operation due to limited amount of space. Patience and a pair of grip pliers
released the hose spring clips. A small section had to be cut between the
moulded bends of the short offside pipe to accommodate the adapter. The near
side was a little more flexible and didn’t require cutting (the moulded bends
just about prevented this anyway); it could be pushed back just enough to take
the T piece.
The Gas Solenoid
Engine compartment gas shut off valve
This was mounted just forward of the battery and directly over the gas-in
connection on the vaporiser. A short length of 8mm copper tubing joined the two
together.
Lambda Chuck
Adjusts the gas supply to the mixers
The chuck connects into the gas pipe between the vaporiser and the mixers
Mixers
Mixes the gas with the incoming air
The mixers did not arrive with the main kit due to the uncertainty of the
correct type required when ordering. They were posted about a week later but
after 8 days of waiting had failed to arrive. Another was sent on the Friday by
next day delivery (Saturday). They finally arrived the following Tuesday,
'better late than never'.
The mixer was fitted into the oval convoluted intake at the front of the engine
and connected to the air flow meter housing using the flexible tubing supplied.
Silicon sealant was used to ensure a leak free fit.
Back fire protection devices
Helps prevent damage in case of backfire
Two of these were supplied and fitted into the air filter box
Injection Emulators
Switches off the injectors and emulates a signal back to the cars ECU when
running on gas.
The control box I mounted on the bulkhead next to the gas solenoid. The left
side inlet manifold was removed to gain access to the injector plugs. The
adapters were then fitted and the manifold replaced with a new gasket and
torqued.
Control Box
The control box I mounted on the bulkhead next to the gas solenoid. The left
side inlet manifold was removed to gain access to the injector plugs. The
adapters were then fitted and the manifold replaced with a new gasket and
torqued.
Gas Piping
This operation was relatively straightforward. With the rear of the car up
on ramps the 6 mm copper tubing was ran over the rear axle, into the tank and
connected. A straight run down the underside (using the existing spare clips),
into the wheel arch and through a drilled hole into the engine bay. Four
securing clips were used at the rear and one inside the front wing. The pipe was
then connected to the gas solenoid.
Miscellaneous Electric's
Control Switch
Dash mounted 3 way control switch / level indicator
After careful consideration, the control switch I fitted under the steering
column.
Not the ideal place for visibility, but the only other option was on the lower
facia where I was a little worried about it getting knocked. I was very glad I
did place it here, where the drilled screw holes could not be seen, as it had to
later be replaced for a smaller control unit pictured right.
The EMU's
These connect inline to the oxygen sensors and emulate signals back to the
cars EEC-V aiding smooth running when changing back to petrol
The 2 EMU's I mounted behind the driver's side facia as these shouldn't require
any adjustment.
Lambda ECU
Picks up signals from the oxygen sensor and acts on the gas flow via the
Lambda chuck
The unit I have placed temporally in the coin tray as it will be required to aid
adjustment of the system for a while.
Wiring
The electric's from the gas tank I run out through the vent pipe, then back
into the boot, under the corner of the back seat and tucked under the floor trim
with out the need to remove any screws,
All the connections were made under the dash; a live was picked up. Eight wires
ran into the engine compartment through the rubber bung behind the o/s
suspension strut. The systems earth was supposed to be made an engine earth
point, however the damn earth strap nut was seized, so it got earthed to the
suspension strut bolt instead.
The two forward oxygen sensors had to be connected into the system. There are
four wires running to each sensor. After testing the voltage, the black wire was
found to be the one required. The wires were cut and soldered connections made.
The air filter box needed to be removed to gain access to the near-side wires.
A connection to the coil negative needed to be made. The pulses from this inform
the control box when to switch to gas. However because the coil is three way
switching the pulses were not rapid enough to switch the system over at the
required revs.
The recommendations are that the control box should be set with the change over
at 2500rpm. But this means flooring a cold Cossie engine to achieve this, and
anyway it wasn't possible to get lower than 2750rpm. I then tried joining
together all three earth wires with inline diodes, but this filtered out the
pulses and the system would not operate.
After FES contacted the manufactures, They sent me out a different control box,
however a week and a half later it had failed to arrive, another was sent out,
and again delivery failed. Another phone call then 2 days later it finally
arrived. An altogether better control box with far more functions than the
original.
I later found after studying some wiring diagrams I obtained that the connection
should have been made to terminal 2 on the ignition control module, had this
have been known it would have saved a lot of messing about.
Low cost LPG Conversions
|
|
|
|
|