US Evap system bad for RoW 911sc? Convert to stock?

[Mtsurfposse]

howdy,

I'm trying to sort out a ROW 1983 SC that was imported. I am looking for a thread or tutorial or advice on the removal of US Evap Emissions and return to EURO spec. The search engine has led me down many rabbit holes, but none of them give more than a tiny piece of the puzzle and hours of reading about unrelated matters to me.

Does the US evap system negatively impact a euro spec car. It has mostly been returned to ROW re. cat delete and proper CIS bits

I don't believe I have an issue with the system as it is now, but I have had intermittent hot/cold start issues and it seemed at times that opening the gas cap relieved excessive pressure and it started leading me to believe the charcoal canister was slow or clogged. It was not always the fix, so it may only be part of the problem which is why I was planning on replacing the expansion tanks and carbon canister.

Apparently my ROW car had the US emissions system applied to it when imported as it has the two tanks in the left front wheel well. It does not appear to attach to the cooling fan, but there is a hose running through my tunnel that ends up somewhere in the engine bay but a haven't found where.

So, convert to EURO? cost? availability? Is the 201-15 diagram below proper for ROW
or
refresh US evap system (new carbon filter, track and attach hose to cooling fan)?
or
Dont do a damn thing thing until I know something is truly broken and I smell gas

[Mtsurfposse]

No one has an opinion?!
Again, no leaking but RoW car with US evap system
Remove and retro Euro system to reduce issues or leave as it till issues?

[76FJ55]

that diagram actually shows both the USA (red rectangle) and ROW (green rectangle) parts. Items 21 and up are for the USA in place of items 17-20 for the ROW cars.

Obviously the ROW system is much simpler than the USA version. Item 17 and 21 are effectively the same type hose only 21 is much longer, so it could be cut down and repurposed as 17. the only real parts needed, to officially convert it back, other than simply removing the extra USA parts is the rubber sleeve (#18, 911-612-865-00), sleeve (#19, 911-201-157-01) and the protective cap (#20, 999-659-015-40).

I don't know the availability to these parts, but even without you could create an effectively similar functioning system by simply running #17 to vent overboard without the sleeves and cap.

[Mtsurfposse]

Thanks 76FJ!

I didnt realize the breakdown between the euro and US was right there.

Do you know of any associated issues that the US EVAP creates for RoW CIS parts?
Since no one else has responded Im gonna presume it is not a common place that creates issues for the AF system and not delete it till I have a problem with fuel vapors entering vehicle

[76FJ55]

Generally it shouldn't cause an issue. If the system is in good operating order with no leaks you will see no benefit from reverting back to the Euro system.

the only thing is that since it ties into the engine vacuum system it gives additional possibilities for introduce unmetered air, if you have any leaks in the system. the Euro system just vents to atmosphere, so completely eliminates any effect on the engine air/fuel metering.

[EC900]

Evap not tied into CIS, but a vac leak will probably have some to blame the CIS and make unnecessary adjustments. Smoke test will find path and any openings of those retrofit US lines.

The (US) required equipment is for gas fume recapture and reuse back into combustion intake nothing else.
Older cars had small expansion tank part #13 in inside the trunk often a source of gas fumes when hoses were old. I take it your Row has it in fender - not to be confused with the larger US exp tank (near headlamp) and the larger washer fluid tank.

It’s a matter of fumes and if you smell them which why some find these useless or unneeded. Char canisters do clog but not to the point of starting issues.
But as stated by 76FJ, an open or unattached hose affect vacuums and idling. Hard hot restarts could be a CIS related among other things.

Engine compartment Evap hoses are behind CIS from tunnel and up to char canister, not easily to trace or readily find which hose is what. The hose from front expansion tank to canister is only 3mm ID.

Try this link for evap line route.

Holy Crap moment (Fuel smell source after fill up that goes away after 30 miles,id'd)

[76FJ55]

Originally Posted by EC900

Evap not tied into CIS, but a vac leak will probably have some to blame the CIS and make unnecessary adjustments. Smoke test will find path and any openings of those retrofit US lines.

The (US) required equipment is for gas fume recapture and reuse back into combustion intake nothing else.
Older cars had small expansion tank part #13 in inside the trunk often a source of gas fumes when hoses were old. I take it your Row has it in fender - not to be confused with the larger US exp tank (near headlamp) and the larger washer fluid tank.

It’s a matter of fumes and if you smell them which why some find these useless or unneeded. Char canisters do clog but not to the point of starting issues.
But as stated by 76FJ, an open or unattached hose affect vacuums and idling. Hard hot restarts could be a CIS related among other things.

Engine compartment Evap hoses are behind CIS from tunnel and up to char canister, not easily to trace or readily find which hose is what. The hose from front expansion tank to canister is only 3mm ID.

Try this link for evap line route.

Holy Crap moment (Fuel smell source after fill up that goes away after 30 miles,id'd)

the diagrams on that thread are for earlier cars and don't correspond with the 83 SC of the OP.

Item #13 would be located in the trunk near the junction of the filler neck and the fuel tank.

Item #1 is the one located in the fender above the washer tank.

both US and Euro cars have #1 and #13 the only difference in the systems occur on the outlet (vent) side of #1 (expansion tank). where, as stated above, the US cars recapture the vapors through the charcoal canister and then draw them into the intake and burn them.