Last update:

08/03/2005

  Installing the system

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Installing the system
Tuning the system

 

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 didnít 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.


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