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against all odds 07-28-2012 04:23 PM

a few electric fuel pump questions:
1) If you are installing an electric fuel pump in a chassis that originally just had an engine mounted mechanical pump----where the fuel lines run into the top of the fuel tank----this means that the electric pump is not gravity fed for a few inches but it is still pretty close to the tank. Is this generally ok and not a problem?

2) In cases where you are still using the stock mechanical pump but also using an electric pump (say for racing) and sometimes you don't use the electric pump---like driving on the street, is this ok for the electric pump? How does this work----does the electric pump just "freewheel" when not turned on? Like if you put a fan outside on a windy day but did not turn it on, i would imagine that the fan would still turn. Would this be harmful to the elec pump?

F-BIRD'88 07-28-2012 05:05 PM

As long as the electric pump is mounted at the back near the fuel tank and mounted level or slightly below or slightly above the fuel level it will work like a charm.

Electric fuel pumps do have ability to "draw" fuel in on the inlet side.

A Carter P4070 makes for a very good axillary "pusher pump" to add onto a performance car with a engine mounted mechanical fuel pump.
The carter pump ensures the mechanical pump does not vapour lock and
sees a steady fuel supply.
You can drive with the electric pump off and switch it on when needed. You can even control it with a WOT "nitrous switch", on the carb,, controlled thru a relay.

against all odds 07-28-2012 06:19 PM

But how does it work when the pump is not turned on? Would this be a restriction in the line somehow?

a) What about TBI to carb conversions? Can we leave the stock electric pump in the tank?

F-BIRD'88 07-28-2012 10:12 PM

Remove the in tank EFI pump and use this pump on TBI to carb conversion.

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