Posted on August 16, 2016 May 29, 2018Do I need a return line? No return line is necessary BUT you can use one if you desire. There are options for plumbing the system both ways. Post navigationPrevious post: Can I use the Command Center with other brand EFI systems?Next post: Does the Fuel Command Center fit in my gas tank? 26 comments on “Do I need a return line?” Justin McNabb September 24, 2016 If I have a high flow fuel pump with a regulator and return supplying 58psi to my fitech1200. do I need an additional return from the throttle body? Thanks justin Bryce - FiTech Tech Pro September 26, 2016 When using an external fuel pressure regulator you can block the return on the throttle body. Joseph Guzman December 16, 2016 So if you run a high flow pump and regulator i will not have to use a return line. I planned on capping the return off my regulator. I just want to make 100% this wont cause a fuel spike Thank you Bryce - FiTech Tech Pro December 19, 2016 You NEED a return regardless with an inline pump fuel system. It comes down to if you are returning from a remote mount regulator or from the built on regulator. Rudolph Jackson November 11, 2016 I have a return line on my mechanical fuel pump, can I use a tee and connect the command center vent to this line? Bryce - FiTech Tech Pro November 11, 2016 Do not tee them together. One is a vent and the other is a fuel return line. If you replace your mechanical pump with one that does not have a return line you can then use this line as a vent line. Rudolph Jackson February 22, 2017 I have a mechanical fuel pump with a return line can I tee the fuel return line from my FCC to the fuel return line on my mechanical fuel pump? Bryce - FiTech Tech Pro February 28, 2017 Your mechanical pumps return line has fuel travelling though it where as the vent on the Fuel Command Center doesn’t. They can NOT be tied together because of this. Jim December 13, 2016 I have a 1995 Chevrolet 5.7 with a TBI I wish to use a adapter plate and put a Direct fuel injection self-learning system do I need a kit to plumb in the inlet and return fuel line? And will be FiTech injection system work with the adapter plate? Thank you Jim Bryce - FiTech Tech Pro December 15, 2016 Our systems do work with adapter plates. You will need to feed the system with a high pressure efi pump like our 40101 fuel pump. R Carlson January 20, 2017 Can you use the stock NOVA fuel tank that has a sender with a small return line on it for the EFI return line? Plan on using the external FiTech EFI pump kit. Bryce - FiTech Tech Pro January 21, 2017 As long as you have a return port that is at least 5/16″. MICHAEL A MARTORANA January 21, 2017 I would like to know if the return port on fitech throttle body is it fuel return or Vapor return line thanks Bryce - FiTech Tech Pro January 23, 2017 The return line returns excess fuel to maintain fuel pressure in the throttle body. MICHAEL A MARTORANA January 23, 2017 Is the return fuel under high pressure Bryce - FiTech Tech Pro January 23, 2017 The return line should have virtually no pressure. tom Segnit February 23, 2017 Does your system come with a fitting to install in the gas tank for the return line… does the return line fitting have to be located at the top of the tank…and can the return line be an approved “soft” line? Thanks! Bryce - FiTech Tech Pro March 2, 2017 Our kit unfortunately will not come with a fitting to put the return into the tank. Michael Hutchings February 26, 2017 350zz4 tank in rear out of tank running aeromotive 100micron in line filter to facet external fuel pump to aeromotive pressure regulator to liqed fuel pressure gage to 40 micron aeromotive filter to 770 double pumper carb due I need a return line. Bryce - FiTech Tech Pro March 7, 2017 All EFI fuel pumps will need a bypass fuel pressure regulator which needs a return line. Brian Stevens February 28, 2017 What if the return/vent line from the Fuel Command center gets a shot of fuel, wouldn’t that scenario act like a p-trap and no longer vent properly? My installation would be in a 1968 Camaro and I want to get it right the first time. Thanks. Bryce - FiTech Tech Pro March 7, 2017 To an extent you are correct but with the elevation change in the line with your setup there wont be an issue. Adam Vineyard March 5, 2017 Hi I’m going to be running your 1200hp system with a inline fuel pump would the Holley 12-800 fuel pump work well with the 1200hp throttle body and im trying to figure out what size return line I will need thanks Bryce - FiTech Tech Pro March 7, 2017 The Holley 12-800 has the same specs as our pt#40102. Though ours is an intank pump we will be offering a drop in module with the pump shortly. Here is a link for information on it. It will retail for $349. https://www.youtube.com/watch?v=qlWuEM5LN5A Curt March 18, 2017 Why does the inline fuel pump require a return to tank when the command center does not? The fuel pump in the command center is the same pump as the inline, so why cant the inline be deadheaded like the command center is? Bryce - FiTech Tech Pro March 21, 2017 The fuel command center has a regulator inside of it which returns to itself. This allows no fuel to be sent back to the tank as it just circulates inside the command center. The inline kit MUST have a regulator to return unused fuel back to the tank.