fuel tank vent line in engine bay question.
09-13-12, 08:24 AM
#1
Rookie
Thread Starter
iTrader: (4)
Join Date: Jul 2012
Location: ca
Posts: 83
Likes: 0
Received 0 Likes
on
0 Posts
fuel tank vent line in engine bay question.
I'm in process of doing a jdm single 2jz swap in my na.
Can I run the vent line to a heavy duty 1 way check valve like from jegs or summit and run it into the intake manifold to pull vac/fumes and when in boost the 1 way check valve plays its part. I ran it like this in many of my honda swaps and I think i also saved a lot of gas at cruise but i know this is not a honda so help me out pro's! thank you
Can I run the vent line to a heavy duty 1 way check valve like from jegs or summit and run it into the intake manifold to pull vac/fumes and when in boost the 1 way check valve plays its part. I ran it like this in many of my honda swaps and I think i also saved a lot of gas at cruise but i know this is not a honda so help me out pro's! thank you
09-13-12, 09:39 AM
#3
Thats pretty much how it is set up stock with a vacuum switching valve controlled by the ecu.
I would suggest leaving it stock if you want to run it to the intake.
You coul'd do it the way you are describing but its not that great to do because you always have vac on the tank.
The idea is for it to only vent into the intake during certain conditions to vent any excess pressure.
Particularly at times when it won't affect the AFR too much.
What you are describing will put the tank under vacuum basically all the time when you are not boosting.
This is not how its supossed to work but I can understand that it does work to a certain degree.
Your fuel pump will be working against the vacuum which is really just as bad as too much pressure.
also if your tank is really full I suspect you could pull fuel into the intake from the vent line with that much vac.
Alot of us just use a fuel filter or the check valve on the line like 93MSB and run it to somewhere else.
I would suggest leaving it stock if you want to run it to the intake.
You coul'd do it the way you are describing but its not that great to do because you always have vac on the tank.
The idea is for it to only vent into the intake during certain conditions to vent any excess pressure.
Particularly at times when it won't affect the AFR too much.
What you are describing will put the tank under vacuum basically all the time when you are not boosting.
This is not how its supossed to work but I can understand that it does work to a certain degree.
Your fuel pump will be working against the vacuum which is really just as bad as too much pressure.
also if your tank is really full I suspect you could pull fuel into the intake from the vent line with that much vac.
Alot of us just use a fuel filter or the check valve on the line like 93MSB and run it to somewhere else.
Last edited by Ali SC3; 09-13-12 at 09:49 AM.
09-14-12, 07:26 AM
#5
Rookie
Thread Starter
iTrader: (4)
Join Date: Jul 2012
Location: ca
Posts: 83
Likes: 0
Received 0 Likes
on
0 Posts
Thats pretty much how it is set up stock with a vacuum switching valve controlled by the ecu.
I would suggest leaving it stock if you want to run it to the intake.
You coul'd do it the way you are describing but its not that great to do because you always have vac on the tank.
The idea is for it to only vent into the intake during certain conditions to vent any excess pressure.
Particularly at times when it won't affect the AFR too much.
What you are describing will put the tank under vacuum basically all the time when you are not boosting.
This is not how its supossed to work but I can understand that it does work to a certain degree.
Your fuel pump will be working against the vacuum which is really just as bad as too much pressure.
also if your tank is really full I suspect you could pull fuel into the intake from the vent line with that much vac.
Alot of us just use a fuel filter or the check valve on the line like 93MSB and run it to somewhere else.
I would suggest leaving it stock if you want to run it to the intake.
You coul'd do it the way you are describing but its not that great to do because you always have vac on the tank.
The idea is for it to only vent into the intake during certain conditions to vent any excess pressure.
Particularly at times when it won't affect the AFR too much.
What you are describing will put the tank under vacuum basically all the time when you are not boosting.
This is not how its supossed to work but I can understand that it does work to a certain degree.
Your fuel pump will be working against the vacuum which is really just as bad as too much pressure.
also if your tank is really full I suspect you could pull fuel into the intake from the vent line with that much vac.
Alot of us just use a fuel filter or the check valve on the line like 93MSB and run it to somewhere else.
would it be possible to keep the charcoal canister stock setup and just relocate it and rout the vac back into the intake by check valve or is that the same thing as what you explained to me on top? it has 2 ports on top. one is the gas tank vent and one go's into the intake manifold with a check valve? i really would like to have it connected some what stockish setup as in function.
09-14-12, 11:28 AM
#6
thats what I just explained, your tank will be under vacuum all the time, which is not a good thing for your fuel pump, but it can work.
It would be better to just vent it somewhere, there is already a vent line if you look under where the canister sits.
stock setup is not a check valve, its what toyota calls a VSV or vacuum switching valve.
The ecu tells it when to turn on, and its usually for like 1 second every once in a while, not all the time.
Its your choice what you want to do really unless you are using the VSV its not going to be like stock basically.
It would be better to just vent it somewhere, there is already a vent line if you look under where the canister sits.
stock setup is not a check valve, its what toyota calls a VSV or vacuum switching valve.
The ecu tells it when to turn on, and its usually for like 1 second every once in a while, not all the time.
Its your choice what you want to do really unless you are using the VSV its not going to be like stock basically.
09-14-12, 06:56 PM
#7
Make sure that line works in the first place. In my car the vent line is clogged inside the fuel tank and between the tank and under the hood. It's so clogged that it will hold full air compressor PSI without budging. As a result my tank over-pressurizes and I'll either have to replace it or rig another vent line to get it working right again.
Thread
Thread Starter
Forum
Replies
Last Post
Frmmli
ES - 6th Gen (2013-2018)
11
02-09-19 04:08 AM
fstlane
GS - 1st Gen (1993-1997)
1
02-02-11 04:44 PM
MangoMan
ES - 1st to 4th Gen (1990-2006)
2
01-26-07 03:46 PM
