IntegraTypeR

iTrader: (1)

Hey guys,
i did a search and part of the search knowing how the the fuel tank is hooked up....well on my civic i have 3 lines going to the stock fuel tank....feed, return and an air hose that looks like vac with a blue thing that looks like a check valve....now since i removed all those environmental/consumption parts now (fuel cansister/purge...etc) i realised some shrink problems in my fuel tank
After some time running the car and turning it off i open the fuel cap to see how the pressure built in, but it seems there is no air pressure built in other than the reverse of that and when i open the cap so much air is forced in the tank (inhale-ing into the tank) that air hose mentioned ealier was fit with a check valve at the front (valve is directed to the direction to let air in the tank and block air going out) and thats with a filter....well i discussed this with a good friend and told me this problem is common on Ford Wranglers and agrees its a fuel tank breathing problem! eventually this effects on the fuel pump performance making my afr go lean on IDLE

what should i do? should i remove that check valve i fit and just put a filter? the reason i put a check valve there from the first place cause i didnt want my engine compartment to smell fuel (by the way running a complete fuel system to a stock tank) and thought about it before fitting it since the fuel tank will need air inhaling and with the valve fit right now it should build pressure NOT shrink as if it cant find air! so confused

what do you gusy think?

thesmogman

See what happen's when you mess with emissions equipment.

But really Ford Wrangler??? Hmmm not. Just messing with you.

OK, you need to have a feed line to the fuel rail. and a return line from the rail back to the tank. Is that what you got?

The third line is for your purge system/carbon cannister. This purge line is suppose to relieve the pressure build-up in the tank. From what I got from your post is that it is creating a vacuum, right? For emissions the tank is sealed. So as you burn the gas you would get a vacuum in the tank. Also gas does expand and contract with the cold/heat too

I'm not sure if a vented gas cap would work for you or not.

Being a smog tech I will tell you about the system but I will not tell you how to bypass it. I think you can figure it out.

IntegraTypeR

iTrader: (1)

ok let start by saying am NOT in CA (overseas) and where i live they dont care about emissions yet! and i never thought you could run this stuff with the fuel upgrade poeple do here? most poeple told me to remove it since it take up space and wont effect fuel delivery when removed (thats not local, but experienced poeple on HT)! i didnt remove the stuff for no reason and have a complete aftermarket fuel setup which consists of:

1- stock fuel tank
2- walbro 255 HP fuel pump
3- feed and return braided fuel hoses (both are -6) with aluminum fittings
4- Aeromotive 10 Micron filter
5- Aeromotive adjustable fpr (base fuel pressure set to 40psi at idle)
6- BDL fuel rail
7- stock injectors (used complete the break in procedure)

i read all the archive posts before fitting anything and found that poeple are putting a check valve where the hose reaches the engine compartment....and to answer your question about the feed and return..yes i have em and yes my tank is creating vacum or trying to while it seems the valve is not doing its job or something and the tank cant find air! the valve works for sure (i cecked it), but i dont know if the tank is creating enough vac to pull it open?!

IntegraTypeR

iTrader: (1)

bump

thesmogman

I think you have the check valve/one way valve the wrong way? I would rather have a build-up of pressure than a vacuum.

I use these valves on the smog machines and have to clean them out every couple of weeks either being stuck open or not opening at all.

Maybe just put a gas filter on it. That will keep the dirt out and it will breathe.

IntegraTypeR

iTrader: (1)

yea thats what am gonna do...remove the valve i fit at the front and put a filter or something, but hey whats that blue thing at the tank....is that a check valve too? well my car was parked for a year and fuel is bad anyway and decided to remove the tank to clean the tank fully (i do know about the drain bolt) but wanted to shake the tank a bit and when i dropped the tank a saw a blue thing which i think is a check valve....what do you think it is (i didnt even touch it)! just remove one hose end to clean the hose with air pressure a bit