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Discussion Starter #1
Hey guys, I installed a electric fuel pump from Summit that is pushing out really high PSI. My solution was to I put a Holley fuel pressure regulator after the pump to control the pressure and it does nothing, I mean nada, still blows thru that regulator like a busted hose.
1) Is the pump to powerful for that regulator (120 GPH)?
2) I'm running a return line to the tank (since the holley regulator had two outlets) is this necessary?
3) Is the pressure regulator to close to the pump?
 

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Hmmm...something doesn't sound right. I have an electric pump which was pushing 14 psi without a regulator and now is at 5.5 with a standard Holley regulator -- which does not have a return line. Have you tightened the adjustment screw in yet?
 

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You really should stick on a fuel pressure gauge and see what you have. 5 PSI is plenty - Are you sure the regulator is plumbed correct?
1. I doubt it - they are pretty stout in design
2. If it's street car you really need a return line. Strictly a track car then a dead head system is ok.
3. The regulator needs to be close to the pump for optimal performance.
 

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Are you sure the pump you have isn't for fuel injection?

It really doesn't matter where the regulator is with respect to the pump just as long as it's between the pump and the carb.

I've never run a return line in 21 years of running electric pumps. I've run them both with and without regulators. My current set up is a 7 lb pump back at the tank with no regulator and no return line. Car runs the same as it did with different pumps and different regulators.
 

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http://vaporworx.com/fuel_delivery_101.htm


I would also add that a return system aids in keeping the fuel flowing and less likely to have vapor lock and heat soak issues. Might make a difference in a stop light to stop light in the dead of summer. If your going to the trouble to plumb it anyway...... I would just figure on adding in a bypass regulator and another line.
 

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Since you already stated you have a return line, I'll ask the obvious question- have you mixed up the regulated and return line ports accidentally? Additionally, like others have said, how do you know if the output is more than 3-7psi if you haven't put a gage on it?
 

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Discussion Starter #7 (Edited)
How I have it plumbed is
Tank to pump, pump to regulator, regulator has two outlets, hose to tank and hose to motor.

One outlet if shooting fuel back into the tank, the other outlet that's going to the motor has no pressure, should I swap them and see what happens? Maybe I'm turning the adjustment knob in the incorrect direction? The regulator has on outlet on the bottom labeled "IN" and the other two outletrs are labeled "OUT"
There's a gauge on the fuel line running to the carb and it read 0...trippy man!
 

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If the output of the regulator is feeding back to your tank, I would see that as being the problem. The regulator 'OUT' should go to the carburetor. I would try plugging off the return to the tank and see if that solves the problem. The second 'OUT' is typically used when feeding a second carb or a fuel gauge.

Andy
 

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^^ yepper - you can use either "out" just cap one off.
 

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Discussion Starter #10
Hey so i took the outlet line off (to the carb) and told my helper to turn the key into the on position to see if i get any fuel, and it was flowing out pretty well, so i guessed that maybe the fuel lines were clogged.
I shot some carb cleaner down the lines and used compressed air to blow it out. A bunch of black stuff came shooting out. After that, i hooked it back up and im getting fuel to the carb. Thx for the help guys!

The bowls arent filling up though so im thinking the float has to be adjusted now. (When i rev it tries to bog out) But it fires up everytime, i just need to adjust the timing and hooked up a vacuum gauge to tune the carb and im golden (at least i hope so)
Cant wait to feel the T5 conversion in the Cat too...
 

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What model /brand fuel pressure regulator are you using??? .. I want to look it ut up but I think you still have it plumbed wrong ....
 

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If your fuel lines between pump and carb were clogged with gunk, what kind of condition is your carb now in? Did you replace your fuel filter at the same time? Some carbs (Edelbrock) have filters/screens in the carburetors as well. I would suspect these long before suspecting a float adjustment- which should never happen if you had the car running before and the float level was fine.
 

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Still think you should plug off the return line to the tank and see if the carb fills properly. If the same regulator output feeds the carb and also returns to the tank, the line with the least back pressure will receive the bulk of the gas flow. Since I would guess the pump and regulator are near the tank, the return line should see the majority of the fuel flow. Ideally the return line should start at the carb fuel inlet and go all the way back to the tank.

Andy
 

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http://documents.holley.com/199r7914-3rev6.pdf

2. The standard regulator, provided with the 12-802-1 pump, has two discharge (out) ports (see Figure 1). In dual carburetor
installations, one port can feed each carburetor. With single carbs, plug one port and feed the carburetor from the other.
Either may be used. Installations should determine choice. See Figure 1.
 

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Discussion Starter #16
Hey thanks a million for that diagram, I have it set up too close to the fuel pump first of all, and the return line is not necessary according to the example.

So turning the adjustment screw in reduces the pressure im assuming?
 

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The regulator comes from Holley with the regulator pressure preset (see table). However, for individual requirements, it
may be readjusted. Loosening the regulator locknut and turning the adjustment screw clockwise increases the pressure.
Decrease pressure by turning the adjustment screw counter-clockwise.
 
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