Fuel Injection - Page 4

Last on November 04 2024

Fuel Filter

This must go in line before the fuel pump. Not only are you protecting the injectors from debris in the fuel, but the pump must also be protected. Pumps are expensive, filters aren't!

Lambda Sensor

This device measures the air/fuel ratio in the exhaust gas, which helps the ECU adjust the mixture so the engine doesn't run too lean or too rich. It should be fitted approximately 6 to 8 inches after the exhaust manifold branches join to become a single pipe. A 16mm (5/8") hole should be drilled in the exhaust pipe, and the sensor boss should be welded into the hole, and then the Lambda sensor screws in to the boss, and sits in the flow of exhaust gases. Ideally, the sensor should also be mounted vertically.

This is the sensor that DTA recommend. It is a Bosch 0 258 104 002 which is one that Webcon supply to Mountune and Pectel for their logging systems. I understand that it is quite special in the way it operates and the original fitment is actually a MAN truck!

It features four wires. Two for the sensor (black=signal, grey=earth), and two for the heater element inside the sensor. The heater element is required for starting, to get the sensor in to its calibrated operating range.

I've shortened the leads, as they were 2M long! I've used an Amphenol water proof connector from WWW.RSWWW.COM, #246-8436. I've also had to crimp the connectors to the wires using a crimp tool, as the grey wire from the sensor just would not take any solder. Its as if its made from steel wire, and not the usual tinned copper wire, so forget trying to solder any connectors on to this sensor cable. Use a crimp tool!

Water Temperature Sensor (WTS)

The ECU needs to know the water temperature of the engine, so it can decide when to switch the electric cooling fan off, to stop the engine from overheating, and to determine if the engine is being started from cold, so the fuel mixture is automatically richened, like the choke works on a carburetor. The WTS I used on the Zetec was from a Jaguar, and didn't fit directly in to the thermostat housing without modifications. Jim Hearne has kindly re-tapped the housing, so the WTS screws in to the same hole as the original sensor. The sensor requires a female AMP mini-timer connector.

Air Temperature Sensor (ATS)

The ECU needs to know the temperature of the air that is being drawn in to the engine. This allows the ECU to vary the mixture, to compensate for the air density, which is proportionate to the air temperature. It needs to be mounted next to the throttle body trumpets, preferably in the air box, or inside the filter element. It requires a female AMP mini-timer connector.

Mini-timer connectors for the sensors

Crimps, fuel injector AMP 2-pin mini-timer connectors, and 3-pin Ford ignition coil connectors are all available from Webcon. (Part numbers are on the Electrics page)

2011 update

Starting in September 2011, I replaced all of the 10 year old braided fuel lines in the car, with Goodridge's Hardline, which is a aluminium tube, that can be bent to shape and cut to length very easily. The most important reason to do this for me, was that the hard lines dont 'breath'. What I mean by that is the flexible lines I was running, were not PTFE lined. This meant that there was a constant odour from the petrol that was allowed to vapourise from inside the flexible lines. The car always stank of petrol inside, and this was very unpleasant to live with.

Hardline tubing is available direct from Goodridge, or any other 3rd party supplier. My tubing was supplied in 2M straight lengths, but you can get it in coils. I wanted straights so I wouldn't have to try to straighten out curved sections, so make it neater more than anything else. The tubes are hand bent to the shapes required, using a pipe flaring tool. And the tubes are then connected to one another using anodised fittings, also available from Goodridge. These allow the fitment of swivel seal connectors to the ends, for the connection of flexible hoses to other fuel system components.

The fitting instructions for hardline connectors, can be seen here.

I've also refreshed the remainder of the fuel system. The car now has a new smaller 20 litre fuel cell, Bosch 044 fuel pump, and 30 micron fuel filter, all from torques.co.uk

Pictures below show the fuel cell being fitted, and the rest of the components.

Because the Jaz 5 Gallon fuel cell is taller than the ATL Cell it replaced, I needed to fabricate a fuel cell cover to give clearance to the top of the cell. I made a drawing, and took it over to Altiss.com and Nigel did his usual 1st rate job.