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.
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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.
The contenders – below are the 3 pumps we considered
Carter AMC Mechanical, 120 gph, 5.5 psi
Carter P4070, 72 gph, 6 psi, Rotary Vane Design
Holley 12-801-1 Red, 97 gph, 7 psi, Rotary Vane Design
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.
