Fuel pump runs steady

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74 360 dart sport

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Hi everyone I have a new quickfuel ss 750 double pump which was used and set while the motor was being dynoed I put a new aeromotive electric fuel pump regulator fluid fill fuel pressure gauge I get the motor and all this installed I start it up fires right off fuel pressure was at 3lbs but the sight glass on the both sides where at the top not in the center and fuel leakage from the bowls I adjust bowls to center on the glass windows adjust fuel pressure to 6.5 lbs pressure still leaking from bowls and glass windows are back to the top and the fuel pump never shuts off what should I be looking for I dont understand why the fuel pump don't shut off I'm thinking there is something wrong with the fuel pump any advice would be greatly appreciated
 
Are they supposed to shut off? I wasn't aware any did that.
 
Might be pushing gas pass the float needle seats. May want to run a return line or drop the pressure..

Also, if there is not a pressure switch, how would the pump turn off without you flipping a switch?
 
Scody21 said:
Might be pushing gas pass the float needle seats. May want to run a return line or drop the pressure..

Also, if there is not a pressure switch, how would the pump turn off without you flipping a switch?
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S'what I was wonderin too.
 
An electronic fuel pump is not designed to be on off on off.

It is designed to be on and provide a particular pressure in the line.

Think you electrical wiring in your home.
There is 120v ( pressure) in the wires to an outlet all the time, no problem.

Same with fuel pump it just runs and builds pressure till it reaches its max design pressure and just stays there till there is flow then the pressure will drop a bit, a well designed pump will have let's say 5 psi at 20 gpm ( just numbers I made up) and 5 psi at 0gpm.

A mechanical fuel pump does the same thing, as long as the cam is rotating the pump is pumping, at some point it will just hold the pressure even if no flow is happening, if you ran the engine off another fuel pump source but kept the mechanical pump hooked up to a dead ended tube with a guage the guage would not just continue to rise till it burst. It would top out at the pressure the pump was set to provide.


If you have excess pressure for your carb you need a regulator.
 
I understand what you are saying maybe this would be a better way of saying it I know the fuel pump does not shut off but when it reaches it's pressure in the line and the carb is full shouldn't it stop pumping until there is flow needed it just keeps pumping fuel with the key in run but motor not running it pushes past the needle and seat runs out from the bottom of the bowls
 
what you need is a return style regulator or a bypass reg if you have a hi pressure pump . with a dead head system which i understand you have no pump will last any amount of time .
 
A friend is running 2 QF’s on a tunnel Ram, floats and needles were adjusted. And any pressure over 4 pounds is pushing gas right past the seats with an electric pump. That right only 4 pounds. A regulator / bypass is necessary...
 
74 360 dart sport said:
I understand what you are saying maybe this would be a better way of saying it I know the fuel pump does not shut off but when it reaches it's pressure in the line and the carb is full shouldn't it stop pumping until there is flow needed it just keeps pumping fuel with the key in run but motor not running it pushes past the needle and seat runs out from the bottom of the bowls
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Does the power company turn off your power if you don't have anything turned on?

On modern FI cars the pump does cycle, but you have a "dumb" pump like a mechanical, it just pumps till the power is off. If you turn off the power the pressure on the line would drop, eventually to nothing.

I suspect you have other problems like float level wrong. If the pressure is at spec at the inlet to the float bowl the needle valve should be able to hold the pressure
 
74 360 dart sport said:
I understand what you are saying maybe this would be a better way of saying it I know the fuel pump does not shut off but when it reaches it's pressure in the line and the carb is full shouldn't it stop pumping until there is flow needed it just keeps pumping fuel with the key in run but motor not running it pushes past the needle and seat runs out from the bottom of the bowls
Click to expand...

No. If the pump is running, it's pumping.
 
74 360 dart sport said:
Part number 11203
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Evidently that pump can use a bypass or deadhead regulator. Those small fuel pressure gauges are pretty much worthless. You need a good pressure gauge and get the pressure under control. 5-5.5 pounds is plenty. Make sure there isn’t any dirt in the needle and seats. I run the float level at the bottom of the sight glass. Learned that from a guy on here. Half way up is on the edge of too high.
 
Hey everyone I got the leak figured out the crush washers for the double pump fuel line kit where not in the groove leak solved git the floats adjusted and the pressure gauge all set runs perfect
 
So it was leaking at the bowl inlet? You may still have issue if the float level is going up from where you set it. If you set it at halfway and you see it creep to the top. You should address that. If it creeps up while idling it can come out of the boosters and vents and pour into the motor. If you have the key on and it the pump is running it can fill a cylinder with fuel and when you go to start it. It can hydro lock that cylinder. Fuel is not compressible.
 
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