M:\Product Information\366-348\Instructions\366-348 MGB Fuel Injection Installation Instructions_Grant_2.doc
Installation Part 16 - Fuel Return Hose
Fuel injection systems use a high pressure fuel pump, which
maintains pressure at the injector. To do so, fuel is constantly
circulating from the tank to the throttle body and back again. We
are going to install the fuel return line.
184. Find the OUT nipple (120.1) on the throttle body. It is
toward the rear of the throttle body, and it points up.
185. Find the large coil (150” approx) of 5/16” fuel hose and
suitable hose clamps supplied in the kit.
186. Slip a hose clamp on the hose, and then connect the
hose (120.2) to the OUT nipple on the throttle body. Tighten
the clamp.
187. Route the fuel hose (120.1) up over the hose to the
brake booster (120.3), then down behind the throttle body
and across the rear of the engine compartment. The fuel
hose must go behind and under the heater hose (important)
as it is routed toward the right hand side of the engine
compartment behind the engine block. Finally, it will go down
and out of the engine compartment (121.1).
188. Zip tie the fuel line to the harness behind the engine
block in a couple of places to make sure it will not rub on
anything (121.2). Because this is a high pressure fuel hose,
take your time and make sure that it will not be rubbing
against any sharp corners or rough edges.
This completes part 16 of the installation
Installation Part 16.5 - Fuel Pump Inertia Switch
A working inertia switch will cut power to the fuel pump in the
event of a collision. Even though the ECU will turn off the fuel
pump 3 seconds after the engine stops running, we strongly
recommend that you run the fuel pump power through the
switch. If your switch is not working and it does not reset when
you push the button on the top, we strongly suggest you obtain a
replacement switch (Moss 900-240).
189. Locate and open the inertia switch wiring kit included in
the EFI kit (bag labeled 772-377).
190. Find the coil of red wire with the white stripe (red-white)
that is part of the fuel injection harness (122.1).
191. Cut the red-white wire 12” from the point where it comes
out of the harness. Two inches from the ends, zip tie the two
red-white wires together. Strip both ends and crimp a butt
connector on each one.
192. Find the 140 inch long piece of red wire included in the
wiring kit. Strip both ends and join the red wire to the red-
white wire using the butt connectors.
193. Feed the loop of red wire through the hole in the firewall
(122.2) into the cockpit.
120.2
120.1
120.3
366-348 Inst Fig 118
366-348 Inst Fig 120
366-348 Inst Fig 121
121.1
121.2
122.1
366-348 Inst Fig 122
366-348 Inst Fig 23
122.2
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