EVAP Delete?

[cidsamuth]

For you guys who have converted your car to track only, have you deleted the EVAP? If so, what steps?

This is common on other platforms, but I can't find anything here. Most of the time, it just entails capping off certain lines and venting the tank to atmosphere.

 

[WannabeST]

I haven't looked into the evap system on my fiesta, I'm sure mine is different from the ST models. But on my mustang the delete was pretty easy. You remove the physical evap box. Then on the big vent line you need to put a check valve on the end of it (If you don't filling up your car will take forever) And the small lines can basically just be left alone. Inside the engine bay there's a line you can delete and cap off after removing. It's a decent chunk of weight reduction. Interested in doing it on this car too.

 

[Jabbit]

I'm interested in this as well, was going to explore it this winter. I was hoping to cut out the spare tire well and flatten that portion as well.

 

[cidsamuth]

Somebody is bound to have done this on our car, and can walk through the basics of "vent from this line, disconnect this line, cap up this line."

@WannabeST . . . funny, as I started down this road with my Mustang also. Ended up abandoning the move though; glad I did, cause I now live in an emissions county. Not worried about it for the track car, though.

 

[dhminer]

Following for replies. Would love to delete the evap system so I can stop replacing the stupid canister purge valve because “unable to bleed fuel tank vacuum”

 

[Bull Run]

I haven't looked into the evap system on my fiesta, I'm sure mine is different from the ST models. But on my mustang the delete was pretty easy. You remove the physical evap box. Then on the big vent line you need to put a check valve on the end of it (If you don't filling up your car will take forever) And the small lines can basically just be left alone. Inside the engine bay there's a line you can delete and cap off after removing. It's a decent chunk of weight reduction. Interested in doing it on this car too.

What kind of check valve did you use for the Mustang?

 

[WannabeST]

What kind of check valve did you use for the Mustang?

A friend gave me one for free since he bought two. There was no markings or brand on it. IIRC the check valve just needs to be 3/8 and vent out (vent to amosphere) so no air should go in to the gas tank. But air should be able to get released.

 

[Bull Run]

A friend gave me one for free since he bought two. There was no markings or brand on it. IIRC the check valve just needs to be 3/8 and vent out (vent to amosphere) so no air should go in to the gas tank. But air should be able to get released.

Thanks for the info, do you happen to know the PSI rating of the check valve? And did you have to do anything to prevent vacuum from forming in the fuel tank as fuel is used?

Factory manual shows three hoses going to the EVAP canister but doesn't say what each of the lines do. I imagine one is from the fuel tank and other goes to the engine bay, but what about the third line? Does the


I'm thinking the check valve should go by the arrow with "x2" on it.


This is a generic EVAP system diagram. It doesn't show the third hose for the canister...

 

[cidsamuth]

The check valve should actually be unnecessary. In the end, you just need the tank to have a means to vent to avoid vapor locking. I’ve see some folks use small filters, but you could conceivably just leave it disconnected.

From there, you are correct that the line to the front should be deleted and capped. Optionally, you want the EVAP turned off in the tune to avoid an engine light, but tuners might not have that option in 2023.

But but but …. your question about the third line is legit …. I’m curious what we do with it.

 

[Bull Run]

My replacement purge valve's working OK so far (knocking on wood), but if I were to go the delete route, I'd attach a hose and filter to prevent gas from splashing out or debris from coming in.

I'll try to trace the third line the next time I'm under the car, but it may be a while since I recently did an oil change and exhaust upgrade.

 

[WannabeST]

Thanks for the info, do you happen to know the PSI rating of the check valve? And did you have to do anything to prevent vacuum from forming in the fuel tank as fuel is used?

Factory manual shows three hoses going to the EVAP canister but doesn't say what each of the lines do. I imagine one is from the fuel tank and other goes to the engine bay, but what about the third line? Does the
View attachment 58665

I'm thinking the check valve should go by the arrow with "x2" on it.
View attachment 58666

This is a generic EVAP system diagram. It doesn't show the third hose for the canister...
View attachment 58667

I could be mistaken but.
One line should be from the fuel tank to the canister
One is canister to engine (to burn the unburnt fumes)
One to atmosphere (to let pressure out)
As other have said. some people just leave the lines without any sort of valve (I've read online this can cause your tank to fill very slowly - don't know why exactly tho since pressure should get out)
I'm not sure what pressure rating the check valve has but I imagine any one way low rating check valve would be fine, as long as you are letting the pressure vent out to atmosphere essentially.

 

[Bull Run]

I could be mistaken but.
One line should be from the fuel tank to the canister
One is canister to engine (to burn the unburnt fumes)
One to atmosphere (to let pressure out)
As other have said. some people just leave the lines without any sort of valve (I've read online this can cause your tank to fill very slowly - don't know why exactly tho since pressure should get out)
I'm not sure what pressure rating the check valve has but I imagine any one way low rating check valve would be fine, as long as you are letting the pressure vent out to atmosphere essentially.

There are actually four lines but two of them are joined by a tee near the gas tank and are the ones going to the canister and engine. I'm not sure that the uncolored forth line goes to in the picture.

View attachment 58707

 

[Bull Run]

Had the rear up for some suspension adjustment so I look a look at evap hoses. The 3rd hose goes to the top of the gas tank.

One option may be to disconnect that hose from the evap canister and attach it to the existing vent hose on the other side and cap everything else.