Phase i, Step 1 – Quick Fuel Technology Qfi Electronic Fuel Injection System User Manual

Page 5

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background image

5

15

ft of 3/8” (0.375” - 9.5 mm)/-06 AN high pressure rated fuel line (reinforced rubber or braided

stainless steel)

If engine is equipped with a spread-bore carburetor (such as a Quadrajet, ThermoQuad, Carter AFB
or Edelbrock) and you do not wish to change manifolds, an adapter to accept the square flange
throttle body is required.

PHASE I:

Install the throttle body assembly, plumbing and other mechanical components

Step 1:

Preparation & disassembly of fuel system on the engine

Disconnect battery cables. Since you are dealing with the fuel and electrical system in this

installation, this step

MUST

be performed.

o Disconnect plumbing (fuel and vacuum) from the carburetor
o Drain the fuel lines into a fuel safe container
o Mark the vacuum lines for relocation on throttle body. On a square bore carburetor (QFT,

Holley, Demon), the vacuum lines attach to the same location on the throttle body.

o Remove the carburetor, avoiding tipping the carburetor and spilling fuel
o After removal, drain the float bowls into the fuel safe container
o Remove the old carburetor to intake gasket.

If you are replacing a large square flange carburetor (Holley 4500, King Demon), you will need an

adapter plate. Use QFT part number 300-4145-1AL.

If replacing a spread-bore carburetor, install an adapter plate to convert to a square flange,

installing a new spread bore carburetor gasket below the adapter, and placing a new square
flange carburetor gasket on the top of the adapter plate.

Install throttle body to intake (NOTE: This may require new, longer carburetor studs)
o Connect the throttle linkage and the throttle return spring. If replacing a square bore

carburetor, the existing throttle linkage/spring assembly can be used. If replacing a spread
bore style carburetor, a new assembly must be purchased. (We suggest QFT p/n 49-3
Throttle Return Kit. Available at leading performance retailers)

o Mount with nuts and lock washers (provided), and tighten. DO NOT over tighten.

Remove the old temperature sensor and
install the provided 3/8-NPT Coolant
Temperature Sensor into the intake
manifold coolant port, as close as possible
to the thermostat. (This may require a
reducer bushing.)
o Connect the Green/Black wiring harness

from the throttle body to the coolant temperature sensor.

See Service Parts list on page

30

should the temperature sensor require replacement in the future.




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