Posted on August 16, 2016 May 29, 2018 by FiTech EFI — 17 CommentsHow do I vent the Command Center? Please read the instructions for the best options for venting your Command Center. This is a very important step so do not skimp out. A hose to the ground is not a vent! Post navigationPrevious post: Does the Fuel Command Center fit in my gas tank?Next post: How many HP is the pump good for? 17 comments on “How do I vent the Command Center?” Larry December 29, 2016 I am running a 350 with the 400 series and fuel command center. It has been up and running for a month. Today I tried adjusting a couple of the AFR’s and had the idle set to 700 and afr of 14.6. it seemed to be ok for a test drive. after sitting for an hour in the cool weather it would not idle, it only runs for about 5 seconds then the power to the fuel center turns off. Engine dies, starts ok, repeats fuel center power loss. Any ideas? Bryce - FiTech Tech Pro January 6, 2017 Check the vent line for any restrictions. Also be sure the set Pump PWM to 40 under ENGINE SETUP. Paul January 25, 2017 Why would fuel be coming out of the command center vent? Bryce - FiTech Tech Pro January 25, 2017 If you run too high of pressure into the Command Center you can blow past the needle and seat hence overfilling it. This can also happen if the needle is stuck open for some reason like debris. Paul January 26, 2017 I noticed the pressure going in to the FCC was between 8 and 9 psi more towards 9, is that going to be a problem? Bryce - FiTech Tech Pro January 26, 2017 Yes this can be a problem. Running too much fuel pressure into the FCC can cause fuel to blow past the needle and seat. I recommend using a low pressure regulator to dial your pressure to 6-7 psi. Paul January 26, 2017 Thanks, other wise running great, very happy. Hector March 8, 2017 Why would the vent line have fuel dumping out under hard acceleration Bryce - FiTech Tech Pro March 8, 2017 This can happen from tank slosh in the Command Center. If the vent is in the rear position on the vehicle this would explain it. Tracey Jones March 9, 2017 Running 3lbs to the fuel command center but fuel is pouring out of the vent Bryce - FiTech Tech Pro March 10, 2017 If their is a constant stream of fuel coming out of the vent the needle and seat are not shutting the fuel flow off. This happens when debris gets stuck in it. You need to pull out and clean the needle and seat. It is the same as a holley needle and seat. Glenn C March 11, 2017 should the fuel command center vent be vented to to the fuel vapor canister or directly back to the fuel tank Bryce - FiTech Tech Pro March 11, 2017 The Command Center vent needs to go directly to the tank. Not to a vapor canister. Glenn Johnson March 22, 2017 Simple question……what size is the command center vent back to gas tank……putting new tank , filler tube , and sending unit , also new S.S. lines,also a 7lb pressure on fuel pump, now need to know what size tube to put in filler neck for the vent…56 BelAir …..Thx… Bryce - FiTech Tech Pro March 23, 2017 the vent line is 5/16″. John Ferber April 7, 2017 I have a constant flow of fuel coming from my command center vent. I have taken apart the unit and checked the float twice and confirmed unit is mounted level. I’m feeding the FCC with a stock mechanical Pontiac fuel pump. Pressure fluctuates between 2-5 at idle and levels out to 3 at higher RPM’s Donnie- FiTech Tech April 7, 2017 If the Float is set properly try cleaning the needle and seat of any debris.