AEM EMS EVAP usage. Found something interesting...UPDATE: post #20
10-07-2015, 01:40 PM
#31
Tonight, for the first time, I noticed a faint "buzzing" coming from underneath the car around the fuel tank area. The sound is very faint, not at all of the level of the fuel pump, and only occurred about once every 90-120 seconds and lasted about 3 seconds.
Once I realized where it was, I loosened the fuel cap (pretty strong rush of air once the seal was broken) and the intermittent buzzing sound stopped for about 10 minutes. After I heard it again I vented the filler cap again, and there was a fairly big rush of air again. The car is in an attached garage so the temp is fairly stable. I can't imagine that much of a pressure difference already existed after only about 10 minutes
So anyway, does this have anything to do with the EVAP system - is there a component that would intermittently make this noise, particularly with an AEM EMS instead of factory ECU?
Once I realized where it was, I loosened the fuel cap (pretty strong rush of air once the seal was broken) and the intermittent buzzing sound stopped for about 10 minutes. After I heard it again I vented the filler cap again, and there was a fairly big rush of air again. The car is in an attached garage so the temp is fairly stable. I can't imagine that much of a pressure difference already existed after only about 10 minutes
So anyway, does this have anything to do with the EVAP system - is there a component that would intermittently make this noise, particularly with an AEM EMS instead of factory ECU?
I don’t know if this is a sign to an issue or potential issue I need to address or not. I do run a larger fuel pump FB340.
10-07-2015, 04:44 PM
#32
Registered User
Thread Starter
Originally Posted by AFs2k' timestamp='1424661197' post='23515323
[quote name='Habitforming' timestamp='1424657927' post='23515280']
Other than reducing emissions from the gas tank, is there any real need to implement this?
Other than reducing emissions from the gas tank, is there any real need to implement this?
I just want to do it right. I've read a lot of people on here have issues with this specific problem... Running the EMS, with the system in place, smelling fuel to the worst, the charcoal canister filling and leaking gas.
I don't want to take it all off and vent it only to have my garage smell heavily of gas when the car sits over night.
I've read that just venting it is a bad thing because 1. durning an accident (roll over mainly) the gas could pour out and possibly ignite. 2. I've also read that a little pressure in a gas tank (around 2psi?) helps reduce cavitation and helps the fuel pump not have to strain.
If I can leave the operation system in place and have it work, that's obviously the perfect solution. If we can't figure it out, and I have to remove it, then so be it. I don't want my tank getting large amounts of pressure in it from it seeing boost, and I don't want it seeing a vacuum like state either. The evap is what controls that.
I'm unsure why you keep saying yours will smell like gas. I've had mine pulled in this car, and my previous 99 Si, and I never had that issues. I have noticed at times a wiff of a gas smell if I am driving, but I've never walked into my garage and thought omg, gas, lol. You'd never know otherwise.
[/quote]
I've left the gas tank open (just open to air) before (as mentioned In the thread...) and my garage smelled like gas. Either way, the smell of gas was not the main problem which you seemed to overlook or missed. I'm very happy you don't have this specific issue, but it seems others do and are using my advice. My garage is fully insulated (all walls, ceiling and doors), my garage could be sealed better than yours as well. I'm just pointing out the fact there are variables with this, hell temp and air pressures come into play as well.
Longish story short, my garage smelled when the car sat.
This is for prevention of gas leaking during a possible roll over and for mechanical pressure relief while maintaining a necessary pressure in the tank. Not having to worry about the smell of gas is a bonus.
05-15-2017, 06:05 AM
#33
Man, I have a lot of threads I need to update...
I opted to just take off everything and go mechanical instead of messing with the sensors and solenoids. I used that $130 2 way check valve in my #15 post. Expensive, but it worked. I bought the stock plastic in tank vent thing from a forum member and figured out how it worked from running tests on it.
Once everything is removed, you'll be left with 2 hoses. A large and a small coming from the tank to the bottom of the car. I ended up leaving the large tube open to atmosphere with a foam fiter on it. It ONLY sucks air in from my testing. It will help replace air in the tank as the pump sucks the fuel. The small line is what does the pressure releasing/venting. It can also suck air in, but it's not as fast to react as the larger hose.
I tested this on the car by removing everything sans the lines, and just leaveing it to sit. My garage smelled heavily of fuel. With the 2 way vent valve in place, I haven't noticed any fuel smells in my garage. I let it sit for a few days and then opened the fuel cap. I didn't get the large rush of air sound, so I know the valve is doing it's job of releasing pressure, but not letting the smell of fuel vapors out. If it had not worked, I'd have gotten the large rush of air as I was taking the cap off.
It does hold a small amount of pressure in the tank (verified by testing), which is a good thing to combat cavitation and help the pump not have to... suck as hard (loss of words).
Sorry for the long windedness. Hope I've helped everyone! Now go out, take the evap stuff off and watch the world burn! LOL.
I opted to just take off everything and go mechanical instead of messing with the sensors and solenoids. I used that $130 2 way check valve in my #15 post. Expensive, but it worked. I bought the stock plastic in tank vent thing from a forum member and figured out how it worked from running tests on it.
Once everything is removed, you'll be left with 2 hoses. A large and a small coming from the tank to the bottom of the car. I ended up leaving the large tube open to atmosphere with a foam fiter on it. It ONLY sucks air in from my testing. It will help replace air in the tank as the pump sucks the fuel. The small line is what does the pressure releasing/venting. It can also suck air in, but it's not as fast to react as the larger hose.
I tested this on the car by removing everything sans the lines, and just leaveing it to sit. My garage smelled heavily of fuel. With the 2 way vent valve in place, I haven't noticed any fuel smells in my garage. I let it sit for a few days and then opened the fuel cap. I didn't get the large rush of air sound, so I know the valve is doing it's job of releasing pressure, but not letting the smell of fuel vapors out. If it had not worked, I'd have gotten the large rush of air as I was taking the cap off.
It does hold a small amount of pressure in the tank (verified by testing), which is a good thing to combat cavitation and help the pump not have to... suck as hard (loss of words).
Sorry for the long windedness. Hope I've helped everyone! Now go out, take the evap stuff off and watch the world burn! LOL.
- completely remove the charcoal canister
- put a breather filter on the large hose
- install the check valve on the small hose
I'll get under my car and check it all out, but would be great if you (or someone else) could share a picture of the inline check valve installed.
Thanks.
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johnzal (12-13-2020)
12-13-2020, 08:50 PM
#35
Just like the rest of you . I removed the evap and charcoal canister because it was full of fuel when i was supercharged on AEMv2. It did stop the smell of raw fuel. But now that I’m stock . The Smell of gas coming form the fuel tank vent hose is really bad. I can’t drive with top on on hot days. Then the smell of gas in the garage. ...
It seem like @AFs2k has found a solution . It expensive but i ready to get rid of this smell. Look like the link is not working anymore. This is the new one I think.
https://fuelsafe.com/tpv8-in-line-pr...ief-vent-valve.
It seem like @AFs2k has found a solution . It expensive but i ready to get rid of this smell. Look like the link is not working anymore. This is the new one I think.
https://fuelsafe.com/tpv8-in-line-pr...ief-vent-valve.
12-13-2020, 08:58 PM
#36
Man, I have a lot of threads I need to update...
I opted to just take off everything and go mechanical instead of messing with the sensors and solenoids. I used that $130 2 way check valve in my #15 post. Expensive, but it worked. I bought the stock plastic in tank vent thing from a forum member and figured out how it worked from running tests on it.
Once everything is removed, you'll be left with 2 hoses. A large and a small coming from the tank to the bottom of the car. I ended up leaving the large tube open to atmosphere with a foam fiter on it. It ONLY sucks air in from my testing. It will help replace air in the tank as the pump sucks the fuel. The small line is what does the pressure releasing/venting. It can also suck air in, but it's not as fast to react as the larger hose.
I tested this on the car by removing everything sans the lines, and just leaveing it to sit. My garage smelled heavily of fuel. With the 2 way vent valve in place, I haven't noticed any fuel smells in my garage. I let it sit for a few days and then opened the fuel cap. I didn't get the large rush of air sound, so I know the valve is doing it's job of releasing pressure, but not letting the smell of fuel vapors out. If it had not worked, I'd have gotten the large rush of air as I was taking the cap off.
It does hold a small amount of pressure in the tank (verified by testing), which is a good thing to combat cavitation and help the pump not have to... suck as hard (loss of words).
Sorry for the long windedness. Hope I've helped everyone! Now go out, take the evap stuff off and watch the world burn! LOL.
I opted to just take off everything and go mechanical instead of messing with the sensors and solenoids. I used that $130 2 way check valve in my #15 post. Expensive, but it worked. I bought the stock plastic in tank vent thing from a forum member and figured out how it worked from running tests on it.
Once everything is removed, you'll be left with 2 hoses. A large and a small coming from the tank to the bottom of the car. I ended up leaving the large tube open to atmosphere with a foam fiter on it. It ONLY sucks air in from my testing. It will help replace air in the tank as the pump sucks the fuel. The small line is what does the pressure releasing/venting. It can also suck air in, but it's not as fast to react as the larger hose.
I tested this on the car by removing everything sans the lines, and just leaveing it to sit. My garage smelled heavily of fuel. With the 2 way vent valve in place, I haven't noticed any fuel smells in my garage. I let it sit for a few days and then opened the fuel cap. I didn't get the large rush of air sound, so I know the valve is doing it's job of releasing pressure, but not letting the smell of fuel vapors out. If it had not worked, I'd have gotten the large rush of air as I was taking the cap off.
It does hold a small amount of pressure in the tank (verified by testing), which is a good thing to combat cavitation and help the pump not have to... suck as hard (loss of words).
Sorry for the long windedness. Hope I've helped everyone! Now go out, take the evap stuff off and watch the world burn! LOL.
12-14-2020, 07:09 AM
#37
12-14-2020, 12:13 PM
#38
This issue was driving me crazy. To the point i was thinking about selling the car or buying all the rear evap stuff and converting my ap1 to run hondata in hopes it would control the evap functions and would lessen the smell... especially when getting home from a drive it would smell like fuel in type garage
i tired to find a alternative product , but it seem like its the only one in the market... this would be a great group buy for all moded s2ks
Edit. Actually there a couple that look like the same design. From mocal, newton. All search come from the UK. It seems the design originates from the UK.
12-14-2020, 02:29 PM
#39
Regarding the larger open hose, I simply zip tied some ~1/4" thick open cell foam around the end of the hose. This simply keeps bugs or debris from wanting to get into the fuel system. Don't sell your S2K. If you are concerned about fuel smell, simply install this pressure relief valve & see how you like it.
12-17-2020, 07:09 AM
#40
Regarding the larger open hose, I simply zip tied some ~1/4" thick open cell foam around the end of the hose. This simply keeps bugs or debris from wanting to get into the fuel system. Don't sell your S2K. If you are concerned about fuel smell, simply install this pressure relief valve & see how you like it.
This issue has been brought up many time here and on Facebook.