Emissions Control System ID help, 1971 Duster 340

PlymCrazy

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1664384511928.png

Hoping you guys can school me on this and may have more questions along the way. Am I correct in saying that's a vapor return line coming out of that breather? And if so, could it be concluded it is an ECS equipped vehicle?
1971 Duster 340 built in Los Angeles.
- Nick
 

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They were trying to contain the vapors. Possibly on all cars in 1971. I had a. Demon that had the vapor return line and no N95.

Do you have N95 on fender tag or broadcast sheet?

do you have the 2” pipe on the driver side inside the trunk? Runs up behind the wheel tub. This is where it would go Through the floor and up. See top bracket up higher?

E1ACF154-AAE7-451F-9C4D-5D01497DFE20.png


03179213-CA35-4860-948B-E4A3692D12A8.jpeg
 
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CFD244

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Yes, ECS. 3 nipple breather is one year only. Expansion tube in the trunk as already stated another indication.......And, 4 fittings on the side of the gas tank.
 

PlymCrazy

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They were trying to contain the vapors. Possibly on all cars in 1971. I had a. Demon that had the vapor return line and no N95.

Do you have N95 on fender tag or broadcast sheet?

do you have the 2” pipe on the driver side inside the trunk? Runs up behind the wheel tub. This is where it would go Through the floor and up. See top bracket up higher?

View attachment 1715991506

View attachment 1715991507
1664390363829.png

I see it, vertical right behind drivers rear wheel well. How about the fill tube? Is that supposed to have a separate vent line running along side it somewhere if everything is original?
 

PlymCrazy

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An yes, N95 is in fact on my fender tag. Looks like I even decoded it as such at one time. But the pieces of the puzzle are finally starting to make some sense as you guys are describing them.

1) Vapor line under the hood attached to breather - check
2) 3-nipple breather on valve cover - check
3) Expansion tube in trunk behind drivers wheel well - check
4) 4 fittings on side of gas tank - have yet to confirm

Anything else you can think of that I can look for as original items still on the car as part of the ECS?
 

67Dart273

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If you do not have one, wander over to the MyMopar site and download a factory service manual, free. In fact you might consider downloading say, 69--73. This will give you an insight to the changes every year, and if you ever upgrade to the 73 / later disk brakes, that is all in the 73 manuals, as well.

Somewhere around 70-71, not all cars had the evap controls. As mentioned, for a couple years, there was a separate vapor separator in the trunk. Somwhere around ? 72-73 this was changed to a separator built into the fuel tank. NOTE THAT THIS line coming from tank to the engine bay IS ALSO THE TANK VENT. DO NOT remove/ block/ plug the line unless you make provisions for venting.


One reason I suggested you download the 69 manual is that the 69 tank vent worked well and was VERY simple.
 

Demonx2

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My 71 Demon 340 was ordered in March 1971 and delivered in the Cleveland, Ohio, area on May 7, 1971. It does NOT have N95 on the VIN tag but it DOES have the vent standpipe in the trunk as shown in the pic (little hard to see in black). With this vent pipe, you also got the 4-vent line tank (although either the 4-vent or the single-vent tank can be used with it!).

I do not claim to know why they used these or not but it was one way of containing tank vapors and sending to engine instead of atmosphere.


20220417_212649.jpg
 

67Dart273

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The "why" is simple---increases in Federal emissions control requirements. As usual, "it started" in CA. CA cars in 70 had the evap stuff
 

PlymCrazy

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If you do not have one, wander over to the MyMopar site and download a factory service manual, free. In fact you might consider downloading say, 69--73. This will give you an insight to the changes every year, and if you ever upgrade to the 73 / later disk brakes, that is all in the 73 manuals, as well.

Somewhere around 70-71, not all cars had the evap controls. As mentioned, for a couple years, there was a separate vapor separator in the trunk. Somwhere around ? 72-73 this was changed to a separator built into the fuel tank. NOTE THAT THIS line coming from tank to the engine bay IS ALSO THE TANK VENT. DO NOT remove/ block/ plug the line unless you make provisions for venting.


One reason I suggested you download the 69 manual is that the 69 tank vent worked well and was VERY simple.
Always a pleasure to hear you chime in. I do have a downloaded FSM for this car and also my B-body car. Didn’t think to look in there about this however I do enjoy interacting with you fellas on here when I get the opportunity.
- Nick
 

PlymCrazy

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How do I confirm I have a true-to-original tank? We’ve confirmed it’s an original N95 setup car. Once the correct tank is confirmed I have to get the correct gas cap. Currently have an aftermarket lockable cap on it and want an original. To date, I’ve returned 2 or 3 that were incorrect. Already started another thread about that issue so forgive the redundance.
 

67Dart273

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Not sure I can help you. Old old thread, possibly originally by OldManMopar, pictured all the caps

-caps-67-70-70-cal-and-71-72-74-75-76-copy-jpg-jpg.jpg
 

CFD244

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How do I confirm I have a true-to-original tank? We’ve confirmed it’s an original N95 setup car. Once the correct tank is confirmed I have to get the correct gas cap. Currently have an aftermarket lockable cap on it and want an original. To date, I’ve returned 2 or 3 that were incorrect. Already started another thread about that issue so forgive the redundance.
So.......ECS was an N95 option in around 1970. In 1971, it appears as though ECS was standard issue (I have a '71 Demon with NO N95, and it has the ECS system, the same as @Demonx2 ). Here is a picture of gas caps used during the various years. Not sure where I got the pic, but probably from FABO. BTW......No vent tube on the ECS filler neck.

Abody Gas Caps 67-70,70 Cal and 71,72-74,75-76.jpg


You beat me Del!:thumbsup:
 

autoxcuda

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An yes, N95 is in fact on my fender tag. Looks like I even decoded it as such at one time. But the pieces of the puzzle are finally starting to make some sense as you guys are describing them.

1) Vapor line under the hood attached to breather - check
2) 3-nipple breather on valve cover - check
3) Expansion tube in trunk behind drivers wheel well - check
4) 4 fittings on side of gas tank - have yet to confirm

Anything else you can think of that I can look for as original items still on the car as part of the ECS?

Is your car and auto or 4spd ? Looks like it’s not A/C

And 71 A-body, 340, auto, N95 will have a bunch more stuff than just the Vapor return line (a 50-state item in 1971)

For an automatic car:
At least-
-vacuum control module on the passenger cowl with vacuum and electrical hook up
-Speed sensor tapped into the speedometer cable
-Vacuum block on motor

N95 stuff in 1971 is SPECIFIC to model, motor, and trans.

A 1971 N95 340 auto A-body will have more stuff than a N95 383 HiPo E-body.
 

PlymCrazy

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Is your car and auto or 4spd ? Looks like it’s not A/C

And 71 A-body, 340, auto, N95 will have a bunch more stuff than just the Vapor return line (a 50-state item in 1971)

For an automatic car:
At least-
-vacuum control module on the passenger cowl with vacuum and electrical hook up
-Speed sensor tapped into the speedometer cable
-Vacuum block on motor

N95 stuff in 1971 is SPECIFIC to model, motor, and trans.

A 1971 N95 340 auto A-body will have more stuff than a N95 383 HiPo E-body.
4-speed car, non A/C
 

PlymCrazy

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Not sure I can help you. Old old thread, possibly originally by OldManMopar, pictured all the caps

View attachment 1715991589
Yes, I have seen this several times. Most recently by @toolmanmike. He was putting up with me in another thread I started inquiring about just the fuel cap itself. Now it’s turned into me trying to understand what all this ECS stuff is.
 

autoxcuda

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4-speed car, non A/C

Not 100% sure on 4speed

The 80k mile N95 340 Demon car that I based my auto info was not messed with very original. I think 2 owner car.

Have you read through the 1971 Repair Manual? There’s a special emissions section
 

PlymCrazy

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Not 100% sure on 4speed

The 80k mile N95 340 Demon car that I based my auto info was not messed with very original. I think 2 owner car.

Have you read through the 1971 Repair Manual? There’s a special emissions section
Sounds like it’s time to start digging in that section of the FSM. Thanks man.
 

PlymCrazy

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Thanks guys for all your input on this. I’ll do some homework in the FSM and circle back if I have anything to add or have more questions. Any further info is more than welcome in the meantime.
- Nick
 

autoxcuda

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I bet this 71 Demon is N95. It’s got a 1971 original issue California license plate in it. Not sure what drivetrain combo it is though.

He might have pulled off any remaining smog stuff too.

 

str12-340

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ECS found in CA emissions cars in 1970, on all A-bodies in 1971. Under the tube attached to the fenderwell (under the car) there should be a sheetmetal cover (easy to remove). It should cover the 4 lines going to the tank and with the cover removed you can verify it is a ECS tank. That tank has a tank within a tank (maybe a gallon?) that has a rubber drain plug on the top of the tank. Photos of an ECS tank out of the car to follow.
 

PlymCrazy

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PlymCrazy

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ECS found in CA emissions cars in 1970, on all A-bodies in 1971. Under the tube attached to the fenderwell (under the car) there should be a sheetmetal cover (easy to remove). It should cover the 4 lines going to the tank and with the cover removed you can verify it is a ECS tank. That tank has a tank within a tank (maybe a gallon?) that has a rubber drain plug on the top of the tank. Photos of an ECS tank out of the car to follow.
Looking forward to seeing that.
 

PlymCrazy

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…on all A-bodies in 1971.
So if ECS was on all A-bodies by 1971, and typically the fuel cap options are either “w/ECS” or “w/o ECS”, I’m seeing just one option I can choose. That would be “w/ECS” and that would make it a ”non-vented” cap, correct?
 

67Dart273

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So if ECS was on all A-bodies by 1971, and typically the fuel cap options are either “w/ECS” or “w/o ECS”, I’m seeing just one option I can choose. That would be “w/ECS” and that would make it a ”non-vented” cap, correct?
Pretty certain "yes" that is no vent on non-ECS
 

str12-340

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here are pics of an ECS tank from a 1970 Dart GT with California emmisions
DSC04102.JPG
DSC04101.JPG
DSC04100.JPG
DSC04099.JPG
 
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