Holley Truck Avenger
Carburetor Install
The jeepfan.com 78 CJ-5 Gets a
new Carb
page 2
A new gasket was
placed on top of the manifold and the carb was
bolted in place following the tightening
procedure outlined in the manual.
Now that the
Getting the carb in is only a small battle in
completing this project. Fuel lines,
throttle cable, vacuum lines, and choke power
are some of the things that need to be hooked
up.
Fuel Pump -
Mechanical vs. Electric
the sleepless nights
Normally this
might be an easy decision but rarely is this the
case when it comes to this Jeep - or any Jeep at
that matter. Here is the list of pros and
cons
Mechanical fuel
pumps are engine driven and require no electric,
are almost completely reliable, and suck the
fuel from the tank. These pumps are prone
to vapor lock and can require extended engine
cranking time to start an engine that hasn't
been run in a while.
Electric fuel
pumps are typically mounted near the tank and
push the fuel which eliminates vapor lock.
These pumps are not dependent of the engine
running so priming the engine when starting is
more efficient. Reliability can be
questionable in electric pumps also noise is a
factor. Replacing a defective electric
pump is easier.
Decision -
Electric
Why? The
biggest reason here is because of this
particular Jeep's setup.
 Since
this Jeep has had the TBI since a complete
rebuild fuel lines have been run specially for
an electric pump and the TBI. Normally a
CJ has fuel lines that run up the drivers side.
This is the side where the engine driven pump
resides. From the pump the lines run up
the front of the engine to the carburetor.
In this Jeep's case the lines run up the
passenger side where they are away from the
exhaust and up to the rear of the engine where
the TBI was. In the interest of reusing
the existing lines the engine driven pump would
need to suck the fuel all the way from the tank
and over the engine and forward to the drivers
side located fuel pump. Most agree that is
asking a lot of a pump that relies on suction.
In this case the electric just seemed to be the
path of least resistance. One more
addition, this engine has never had an engine
driven pump since a complete rebuild in 1997.
Now, what pump
to use?
In surfing the
forums and articles it came down to two electric
pumps. First off, using an electric pump
designed for carburetors is a wise choice since
these pumps operate in the 5 to 7 psi range and
do not require a pressure regulator/return line.
The two most common pumps found were the Holley
Red and the Carter 4070. Both made by
quality manufacturers and fit within specs to
work with a carb. See details on the
right.
 The
Carter was the pump that was chosen. It
seemed that most agree the Carter is less noisy
and most reliable. The Carter does run at
a lower pressure and has a lower flow rate but
this Jeep's 360 is only a bit more built than
stock.
Electric Fuel
Pump Safety and Wiring
 In
the event of a collision or engine malfunction
an oil pressure safety switch should be
installed to prevent the electric pump to
continue pumping when the engine is not running.
Many varieties of these switches are available.
The switch will be wired so the switch will run
in bypass during engine cranking and through a 3
way switch inside the Jeep. The 3 way
switch will operate in normal, prime, and off.
This carburetor will hole enough fuel in the
fuel bowls to start the Jeep without the pump
unless it has sat for a while. More on
this later.
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