Sup guys! So I've done a lot of reading on the subject of the removal of the evap system (charcoal canister, valves, hoses, etc.) online, and could never really get a definitive answer on the subject. Alot people have removed the evap system, but there's very little documentation on it. There's quite a few components involved in the system, so it can get pretty confusing very quickly; there's usually a lot of questions, but not a lot of answers in the form of pictures and detailed explanations. I'm hoping I can help people out with what I've learned and compiled through reading essentially every thread on the subject here and other places online, so people can confidently remove the evap system on their cars. If any of you spot any errors or can add any information, please do so. I'm trying to finally get together a solid & informative DIY for the removal of the evap system & all related components, so whatever input anyone has, feel free to add on to this thread and/or correct me.

For starters, why remove the Evap system? The evap system is purely an emissions control device. It collects fuel vapors from the fuel tank during refueling & normal operation & recycles those vapors into the intake manifold vs venting them to atmosphere, plain and simple. Most cars used to just vent these vapors to the atmosphere via a breather on the tank or a vented gas cap until it was absolutely mandated in the early 2000s that ALL cars be fitted with these systems. That being said, a majority of people who boost these cars are running a standalone ecu, which no longer operates the evap system. So not only is the system rendered redundant & dead weight, what's worse is with the system rendered inoperable, the buildup of these vapors within the system eventually leads to the charcoal canister & associated lines & hoses becoming saturated with fuel which eventually will either leak or constantly smell of fuel as the vapors are no longer being burned off by being ingested into the intake manifold. What's worse still is if people overfill their cars at the gas pump, the lines on the filler pipe for the fuel tank will ingest the excess fuel, and if this system becomes completely inundated with fuel it will eventually become fully backed up & the tank will no longer be able to breathe, and you'll have a pressure buildup within the tank that will make filling the tank at the pump difficult as the back-pressure will constantly kick the fuel nozzle off at the gas pump which has been a source of frustration for some people.

The fuel tank NEEDS to breathe. You cannot simply remove the system & cap all associated lines; you need to allow the fuel tank to breathe by allowing fresh air into the tank to replace the volume of fuel lost by consumption. I can go into plenty of scientific explanation about this, but in the end I'll keep it simple. You want to maintain a balance of slightly positive pressure within the fuel tank. You do not want a vacuum scenario, and you also do not want too much pressure buildup - both have consequences on the fueling system. That being said, the fuel tank both needs to be able to ingest fresh air as the fuel level depletes, but at the same time needs to be able to relieve the excess pressure within the tank because if it does not, heat will build up and the fuel will actually begin to boil, which is why some people report a gurgling sound from their fuel tank. Both scenarios result in much more strain being placed on the fuel pump, which can cause delivery problems as well as eventual complete failure of the fuel pump.

The easiest & cheapest solution to this is to simply remove the evap system & leaving the two lines coming off of the tank open to atmosphere. The larger plastic hose with push-lock fittings is for vacuum. It allows air IN to the tank only. The smaller rubber hose is the actual fuel tank vent hose. This is what allows the tank to expel any excess vapor buildup. But simply leaving this one open to atmosphere poses 2 issues. One will be that since this opens the system to the atmosphere, your fuel will be able to evaporate from the tank slowly, but secondly, it will be constantly venting vapors, so if you park your car in a garage you'll unsurprisingly be welcomed to the entire space filling with the smell of fuel after some time, as well as sometimes being able to smell fumes while driving as well. Some people report this happening, others do not. I'd attribute that to some people simply being more sensitive to the smell of fuel than others, but on this particular car and setup, leaving this line open WILL result in the vapors constantly leaving the tank.







What you want is a check valve on the end of the rubber vent line. One that maintains pressure to a certain point, but releases the excess. So while the car is running any excess pressure build-up in the tank can be relieved, but at rest in your garage, the vapors will be held in. The only exception is if the car is sitting in the sun or a HOT garage with a full tank of gas, the valve will occasionally open to release pressure buildup, but without the stench. The go-to solution for such a check valve is the Newton TPV8 in-line vent valve: https://www.newton-equipment.com/tan...ne-valves.html



This valve is sold by various retailers, such as Mocal, but the brand is still Newton. The markings on the valve also seem to have differed over time, but the orientation & function has not changed. I believe they've continually revised the markings to provide a better understanding of which way the valve should be connected, as the one I received was different from the one pictured above. No instructions are provided, but the side with the groove closer to one end should be connected to the vent line, and the other end either left open to atmosphere or you can install a breather on the 8mm (5/16") nipple. Below is the valve I received:






Anyways I'm just going to get right into it. I completely removed my entire evap system. Perhaps someone might want to play with keeping the intake manifold hooked up to the vent valve, so the gasses are vented / sucked into the intake manifold instead of vented to the atmosphere. Be my guest. I opted to just remove everything and cap off all of the ports. Unfortunately I didn't take pictures of all of the stuff I removed, so I just pulled some from online:

Under the hood there's a solenoid mounted to the driver's side frame rail with a hose going to a T off of the intake manifold as well as to a hard line which runs along the bottom of the car to the back.



I removed the stuff pictured above, & capped both ports on my intake manifold.






I also capped off the hard line that the solenoid was attached to. When you're done, this hardline will be open on both ends; you don't really need to cap it, but I had an assortment of vacuum caps laying around, so I did. 3/8 or 5/16 ID caps should work.





Making your way to the back of the car you'll be removing the charcoal canister & ALL associated hoses, solenoids, brackets, etc.



The only thing not pictured is the black metal shield that sits below it that's attached to the canister bracket & rear subframe cross bar. Once all of this is removed you're going to be left with the 2 lines pictured above coming off of the fuel tank. There's one other hose that connects to the subframe to a white/tan plastic fitting. That's a "drain" for the vented air when the canister needs to release excess pressure; I ended up just leaving it open with nothing connected to the fitting. Maybe in the future I'll get a silicone cap for it; when I do, I'll update the thread.


*UPDATE* the OD of the plastic nipple is .700". I used a coolant bypass cap to cover this, Dorman P/N 02251.





Here's the other end of the hard line I capped off:



For the 3 connectors that were removed, I ended up untaping all of the factory electrical tape, removing the factory loom, and bundling the wires together so they're shorter, re-wrapped with electrical tape, and zip-tied them to one of the hard fuel lines. Do whatever you see fit with these. Ideally what I'd like to find is a blanking plug for the factory grommet hole, and just push the wires/connectors back into the body and pop the plug in. If I end up doing this I'll be sure to update the thread with the appropriate information.




*UPDATE* I ended up blanking it off; see post #26 for a more comprehensive explanation:





At this point all that's left is to attach & secure the valve & breather hose. There's a variety of ways to do this, but this is how I ended up doing it:








I used 2 of the 4 now un-used mounting holes left behind by the charcoal canister and mounted the valve / breather hose with stainless steel cushion clamps & bolts (the factory bolt/washers won't work on the cushion clamps, the washer is too wide). For the valve I simply attached it to the rubber hose where it used to attach to the evap system & re-used the factory spring clamp & secured it with a 1.25" ID cushion clamp. (Again, please pay specific attention to the orientation of the valve so you don't connect it backwards!) I opted to put a breather filter on the other end / outlet of the valve (K&N 62-2470). For the corrugated plastic breather hose I secured it with a 9/16" ID cushion clamp and put a breather filter (K&N 62-1370) over the plastic connector/shell to ensure nothing can get sucked into the tank. You can leave this open potentially, but I wouldn't advise it. Make efforts to ensure nothing can get sucked into this hose; zip tie some foam around the end for a cheaper solution if you must.


Long story short, everything works as it should. I ran the car after getting everything installed, and after a time I noticed a faint, intermittent humming noise. To my surprise it was the valve doing it's job! As fuel is being drawn out, and air is being drawn in to the tank, the pressure slowly builds, and eventually it reaches the threshold where the valve opens to relieve it. It would stay open for about 10 seconds at a time, and then close again. I verified that it was the valve because I could actually feel it venting through the breather filter, as well as see the vapor shadows on the body of the car when I would shine a light on it while it was venting. Laying directly under it, there was a very faint smell of fuel when it vents, but that's literally with my face right there, and the smell dissipates immediately. At some points I even needed to cup my hand and fan it towards myself to get a whiff of fuel, otherwise I couldn't smell it. I imagine if the vent hose was left open as opposed to the valve there'd be a much higher concentration of vapor smell.

I took a short video of the valve operating so you could hear it. The sound is very faint, but very audible in the video because my phone was essentially right up to it. You can hear the valve open at around the 10 second mark. While driving you won't hear it.





Once I got done, I shut the car off and loosened the gas cap; there was a release of pressure so the valve was also doing it's job of maintaining a small amount of pressure within the tank while remaining closed to keep the vapors in. When the pressure released from the gas cap, I also heard a vacuum sound from below the car which was undoubtedly the plastic breather hose ingesting fresh air, indicating the function of the 2-way valve on top of the fuel tank only allowing air in through the larger plastic hose. While the car was running, this hose was not allowing the release of any vapor as I could not see / hear / feel anything coming out of it; it's sole function is to only allow air in.


That should be it. I'll keep everything updated as I spend more time with everything, but thus far no issues.

Big shoutout to @Road racer & @AFs2k near the end of this thread: https://www.s2ki.com/forums/s2000-fo...1114572/page4/

They did most of the pioneering, I simply compiled everything and outlined it with pictures. They're the real MVPs.

Here's a link to where I bought this valve: https://www.demon-tweeks.com/us/moca...valve-moctpv8/

It's branded as Mocal, but it's still stamped Newton. I think I paid roughly $70 total shipped from the UK and had it within about a week. Here's how it came:




Please do not pay more than $100 total for this thing. There's only ONE TPV8 valve, and it's made by Newton. Others in the thread linked above complained about the price from here: https://fuelsafe.com/tpv8-in-line-pr...ef-vent-valve/

I can assure you it's the exact same part marked up to nearly over triple the price. Don't buy from there.


Also shoutout to @RAIN H8R who made me type up this DIY. I wanted him to do it and I was just going to supply the pictures because I'm lazy, but he busted my balls as he's so good at doing, so here ya go, screw you, dad! Have fun...

 

Excellent write up! This will be a valuable post for people looking to do the same. I have been using this setup for ~6 years now and have not had any problems or complaints. I never think about it really. Again, good job!

 

Thank you for pioneering it! The biggest thing was figuring out the functions of the 2 hoses coming off of the tank as well as what you did with them. Had you not tested the 2-way valve coming off of the tank I don't think anyone would have. Appreciate your research and sharing of the information!

 

Thanks Kyle. However, I can't take credit for this as it came from my buddy AFs2K (from the #20 post in the original thread). He is the true pioneer.

Chris
www.roadracerproducts.com

 

This is great, well done! I like removing random crap from my car, wondered a couple of times in the past what I could do with the EVAP stuff but never got around to it. Now with everything already laid out for me by you I will have to do it, haha!
I had both a straight vent to atmosphere, and a straight vent to intake manifold setup on other cars years ago, but that also would cause fuel smell in the garage. But this setup with the check valve definitely sounds like the way to go.

 

Edited my post giving him credit as well, thanks for the correction, Chris!

P.S. love the beefed-up Vortech mount bracket you sell. I purchased one from you a year or two ago to send to @RolanTHUNDER over in South Africa for his setup. Very nice piece.

 

Great write up man!

 

I remember early in the 2000's mods would actually Sticky usefull information. Sadly the ones on S2KI mostly seem to post up on non-car related threads. Another reason why this forum is dying.

 

Ordered my tpv8. Thank you!

 

Luckily this forum is still very much a wealth of information for the people looking & asking the right questions. The only unfortunate thing is that a majority of the pictures posted long ago that were hosted externally are no longer there, which really sucks. It seems that nowadays people would rather just ask questions on social media platforms vs forum discussion & writeups.....I'd say the forum model can almost be directly attributed to a physical book now in terms of peoples willingness of wanting to pick one up and read.....But for the people who do, the reward is there.