AEM EMS EVAP usage. Found something interesting...UPDATE: post #20
04-05-2015, 08:15 PM
#21
to the OP - if this is too off topic and you want it deleted, just ask. this seems like a good place to ask the question though as I think it relates to EVAP and there are a lot of sharp minds here...
Tonight, for the first time, I noticed a faint "buzzing" coming from underneath the car around the fuel tank area. I have an '04 with the new KW s/c and AEM Series 2. The car had been parked for several hours when I noticed it. 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. Took me about 10 minutes to locate it, it was so subtle.
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?
Tonight, for the first time, I noticed a faint "buzzing" coming from underneath the car around the fuel tank area. I have an '04 with the new KW s/c and AEM Series 2. The car had been parked for several hours when I noticed it. 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. Took me about 10 minutes to locate it, it was so subtle.
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?
04-17-2015, 05:07 AM
#22
Bump, abs also hoping someone else tries to get this worked out on the series 2. I finally had a big event to go put the car through its paces, and after a long, periodically aggressive highway run there was a tremendous exhale of very hot fumes from the tank once I stopped for fuel.
Also getting a very strong raw fuel smell every time I come to a stop after a spirited drive.
Car seems to run ok though, so at least there's that.
Also getting a very strong raw fuel smell every time I come to a stop after a spirited drive.
Car seems to run ok though, so at least there's that.
04-21-2015, 07:02 AM
#26
The OP recently came over to my house and we pulled the EVAP system. We installed the 2 way valve (post #15) to the small hose coming from the tank & zip tied it to the subframe where the old EVAP mount holes were located. I used some open cell foam & a hose clamp on the big hose to keep return air clean going into the tank. So far, no issues with fuel smell & the tank is holding pressure. However, I have only driven it on short local runs since I did all this. The true test will see how it does when I have another day of spirited driving in warmer/hot weather. If I do get some excess gas smell, I might try to make a charcoal canister with some PVC pipe & some activated carbon from a fish store. I found some info on the web regarding this approach.
04-21-2015, 01:54 PM
#27
Can you all provide a bit more info? Which line did you use for a vent, and did you cap it with anything, or use that $120 valve mentioned above?
10-06-2015, 12:00 PM
#28
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.
This is exactly what I've been looking for and saves me from doing the testing you did. Thanks!
10-07-2015, 12:31 PM
#29
Registered User
Originally Posted by Habitforming' timestamp='1424657927' post='23515280
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.
10-07-2015, 01:30 PM
#30
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.
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I keep mine under a car cover in 90* heat and i still dont have any smell of fumes in the car. I recently added a surge tank in place of my evap. This and a few other threads helped me get the job done. link below.
https://www.s2ki.com/s2000/topic/113...e-tank-option/