ELECTRIC FUEL PUMP

[juggernaught]

When I bought my cj7 it had an electric pump mounted "in-line" with the mechanical pump. In order to use the electric pump you had to "break" the fuel line at the filter and clamp the pump into the line.It was already wired to a switch on the dash.

My question would be.....Is it ok to run the electric pump throught the mechanical pump (while the mech. pump is still running)? It was obviously run this way as there is no seperate fuel line from the elctric pump that bypassed the mech.pump.

My guess would be that he ran the elect. pump when off-roading at low rpm. Originally there was a m/c 2100 2bbl. carb. on the 360. Since my rebuild, I have had no problems running the t/a holley 670 @ 700rpm in low range (tera low 80:1).

I would like to set up the elect. fuel pump for a back-up and need to know if I need to run a seperate fuel line or if it will pump straight through the mech. pump. Seems that it must have worked O.K. the way it was originally plumbed.

[tufcj]

Where is the electric pump mounted?

It should be in the back, as close to the tank as possible. Electric pumps are built to push fuel, not draw it. If the output of the electric pump doesn't exceed about 6 PSI, then it's perfectly OK to use it to push fuel to the mechanical pump. I've seen it done many times to reduce vapor lock. Fuel under pressure has a higher boiling point than fuel under vacuum. Some electric pumps will block the fuel flow if they fail (or aren't turned on). Just be aware of that.

Bob
tufcj