Heres the first in a series to help anyone considering the Zetec Upgrade, I have compiled these posts from mainly information off the forums, so a big thanks to everyone who has shared thier data with us.
I will be adding and updating these posts as we find out more so keep an eye on the edited date at the bottom of the post and reread it for the latest information.
Fuel System:
Carbs or Injection:
The choice to use Carbs or Injection is an inportant one, think about the following:
1) Type of Fuel system (High or Low pressure).
High Pressure will need as a minimum:
:: High Pressure Pump
:: EFI Filter
:: High Pressure Fuel Lines, including a return to the tank
:: Fuel Pressure Regulator
:: Fuel Rail for the Injectors
:: Injectors
:: An injector boss (in the manifold or Throttle Bodies)
:: Throttle Bodies
:: Fuel ECU
Where as a low pressure system needs a Red Top Pump and a Filter King Regulator.
2) ECU Required (Ignition Only or Full EMS).
Ignition Only ECUs are quite cheap and readily found secondhand circa £150, Full Ignition and Fuel however will cost more luckily many new ones are around costing £350 upwards.
Inlet Manifold:
A DCOE flanged manifold will take DCOE carbs like webbers of Delortos, you can also fine Throttle Bodies designed to replace carbs with this flange on them, they must have an injector mount in the throttle bodies.
DCOE CARBURETORS
DCOE TYPE THROTTLE BODIES
A good way of getting an impressive setup is like Richard Chambers has done, an ST170 inlet manifold, fuel rail and rubbers are used to mount Motorbike Throttle Bodies:
FOCUS ST170 INLET SYSTEM
MOTORBIKE THROTTLE BODIES
CHECKING THE SPACING
The motorbike throttlebodies come in a variaty of sizes 38mm being the norm. A few modifications will be needed to make them fit:
1) The bore spacing will need enlarging, it is important to add here some motorbike throttle bodies are cast togethter so the best ones to get are off the 2000-2004 modles of GSZR600 and GSXR750 or other ones that can be split. Spacers can be made to go between the indivudial bodies to equel them out to match the ST170's manifold's spacing. The original fuel rail and injectors will need to be removed and the injector holes plugged up a small core plug will suffice.
2) The ST170 Fule rail will need to be modified to take a fuel pressure regulator as the Focus pumps are pressure sensing (CVH EFI one will do) and a return outlet added to the pipe, as a not the thing on the centre of the pipe is to dapen the pulses in the fuel rail and can be left in place.
Tank, Pump and Filter
If your not going to use Injection then the standard tank need no consideration.
If you are turning to Injection then your quite lucky as the tall tank in the Escort has a fairly good design for a fuel injection system, I know many people who have simply fitted a pump and filter in line with the outlet (enlarged), as a general rule keep the tank above a 1/4 full. Its best to thorougly clean the tank out to get free of any debris before swapping to EFI, a new union can be fitted in the bottom the OD (Outside Diameter) of the outlet shoud equal the OD of the new pump so a simple rubber fuel pipe can be used to connect them. A return is required for the fuel thats bled off by the regulator, the RS Series had a return which can be reused, if you dont have one I suggest removing the level sensor and fitting one to it.
Any Fuel Injection Pump should do a sierra one is a good bet, it should be fed with a good quality wire and switch via a relay controlled from the ECU.
SIERRA FUEL PUMP
A few choices for filter, if your using a sierra pump then use the whole sierra cradle and filter the pipes and connectors will then all fit. You may however consider using a filter with push on fitting so a jubille can be used to retain the pipe.
A word of warning though EFi fuel pressures are near 50PSI and when a leak is present it hightly dangerous so care and attention should be excersised when designing the layout of the systems.
Notes
A friend of mine is using a XR2 twin choke and manifold on his 1.8 Zetec, he said he had the redrill the head and get the carb set up on the rollers which cost £65 but it runs very well.
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