• July 5, 2022

Does A Fuel Pressure Regulator Return Fuel?

Does a fuel pressure regulator return fuel? Return, or bypass, style regulators are characterized by a fuel return line from the regulator back to the fuel tank. A vacuum/boost reference port allows the regulator to compensate for boost pressure with forced induction applications (F).

Do I need a return style fuel pressure regulator?

A return-style regulator offers a few benefits over Blocking Regulators: The regulator reacts faster to changes in engine load. It supplies more consistent and accurate fuel pressure. This reduces Lean Condition spikes.

What is a return style fuel pressure regulator?

A return style regulator or bypass does exactly what the name implies, it bleeds off excess pressure in a return line back to the fuel tank. As the regulator sends excess pressure back to the tank you can expect a reliable operating pressure supplied to the fuel rail or carb.

Is the fuel pressure regulator on the return side?

In a street/strip application we recommend running the feed line directly to the carburetors fuel log then placing the regulator on the return line side of your fuel log. This allows the fuel to flow unrestricted to your carburetor, but still regulates the pressure and returns the unused fuel back into the gas tank.

How do you hook up a fuel pressure regulator with a return line?


Related guide for Does A Fuel Pressure Regulator Return Fuel?


Do you need a fuel return line?

Any restriction on the return side will create back pressure and limit the regulator's capability. A free flowing return line maintains consistent pressure in the system. Ending the return above the fuel level in the tank, or in the filler neck will cause aeration. This can lead to fuel starvation and pump wear.


Can you run a fuel pressure regulator without a return line?

A non-return style regulator offers a few benefits over Bypass Regulators: Plumbing does not require a return line. Less weight, complexity, and cost.


Is there fuel pressure on return line?

There is NO WAY there is that much pressure in a return line unless there is a problem with the line (blockage, kink, etc). If the tank was full of water, it would cause 0.25 PSI of pressure in the fuel line if it had 7" of fuel above the return.


Does a low pressure fuel pump need a return line?

A return, while not necessary, is certainly nice to have as it makes the fuel pump's life much easier. It keeps the fuel pump from fighting dead head pressure and that will make the pump ultimately last longer.


Can I use a different fuel pressure regulator?


How does a return fuel system work?


Do carbureted engines require a high pressure fuel pump?

A fuel pump is not necessarily required for the engine to function. The low-pressure fuel needed by a carbureted engine can be supplied simply by mounting the tank higher than the carburetor and allowing fuel to feed with gravity.


Does a carbureted engine need a fuel return line?

Truth be told, many carbureted engines run just fine with a deadhead-style fuel system. In contrast, a bypass regulator bleeds off excess fuel pressure, dumps it into a return line, and re-circulates the fuel back into the tank.


Does a electric fuel pump need a fuel pressure regulator?

When choosing a fuel pressure regulator for your ride, you need to take into consideration several factors. Most lever style mechanical fuel pumps don't require a regulator and some electric fuel pumps even have the regulator built right into them, and eliminating the need to purchase an external unit.


Where should I mount my fuel pressure regulator?

The optimum EFI regulator location is after the fuel rail(s) when possible. All pump flow, minus engine consumption, must always run to the regulator, wherever it is. Putting it after the fuel rail means all fuel must run through the fuel rail, and over the injector inlet, at all times.


How do I install a fuel return line?


Can you use an electric fuel pump with a carburetor?

Electric fuel pumps come in three basic types. As long as a fuel pump provides the Flow Rate your engine needs at the pressure your Fuel Injected or Carbureted system requires, it will work just fine.


Is a fuel pressure regulator necessary?

The fuel pressure regulator is necessary for the proper running and optimal performance of the pressure and the car's internal fuel system, providing the injectors' required support.


Why is there a fuel return line?

It's primary purpose is to return excess fuel from the carburetor to the fuel pump, however it serves other important functions as well. Aside from providing a path for excess fuel to return to the tank, the fuel return hose also prevents vapor lock and over pressurization from occurring within the carburetor.


Which fuel line is the return line?


What causes fuel not to return?

The only things that are likely to cause fuel not to return are either a failed fuel pressure regulator, or an obstruction in the fuel rail. If it doesn't, then you will need to have a qualified professional, such as one from YourMechanic, inspect the fuel system and diagnose the cause of the no start condition.


How do you bypass a fuel regulator?


What is the correct fuel pressure for a carburetor?

Fuel pressure should be set between 6 and 8 psi for a gasoline carburetor. An alcohol carburetor is a different animal with very different requirements. The Alky carburetor will require 4 to 5 psi at idle and 9 to 12 psi at wide open throttle. Remember, fuel pressure is not a substitute for volume!


What is a bypass style fuel pressure regulator?

A bypass regulator creates pressure by restricting flow from the pump, forcing the pump to produce pressure up to the regulator's set point. Once enough pressure is created the regulator bypass is forced open, allowing excess flow onto the return line.


Can a fuel return line be too big?

The return line has to flow enough not to create a back pressure on the regulator. This will effect fuel flow and pressure on the rail side. You cannot go to big.


Can you block off fuel return line?

Any fuel going through the return line is simply fuel your engine did not need/could not use. Blocking or restricting the line only increases fuel pressure at the injectors. Blocking the line results in the fuel pressure just being the maximum the pump can push.


Why does a diesel engine have a return fuel line?

the fuel pump capacity

provides more fuel than the engine requiresso the extra is returned to the tank. Same as on your fuel injected carit's called a fuel loop.


Can you run two fuel regulators?

Regulator 2 should run just one line to the fuel solenoid and block off the second port of the regulator. Yes you do need 2 fuel pressure gauges to adjust the system correctly. Make sure you flow the plate at 6 psi and run 900 psi at the bottle. It is very important to check the sytem with it flowing.


Can a fuel pressure regulator stuck open?

Once you have triggered the fuel pump, and you still have low or no fuel pressure, it could mean the fuel pressure regulator is leaking or stuck open. However, if the fuel pressure is high, it could mean the fuel pressure regulator is stuck closed.


Will a bigger fuel pump increase horsepower?

The amount of horsepower that your engine has will determine how much fuel flow is required to support that engine. As horsepower increases so does the volume of fuel required to support that power. For example if your pump flows at 50 gph it should be able to support a 500 hp engine (50 x 10 = 500).


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