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Discussion Starter · #1 ·
I own a 85 Dodge RamCharger (V8 318 5.2L.) I've had so many issues with this truck sense I bought it, now I got one problem left. I can't get my truck to pass the Evap Tests at the smog shop. So I'm guessing my Evap system has a leak somewhere and before I start tearing into it, i would like to know if anyone has some diagrams that can map out what i'm going to be tearing into.

I've been trying to get this truck smogged and this is the last thing left on the plate that doesn't want to pass. Any info and help would be much appreciated. 

Mikhail
 

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I don't have a diagram for you.  Your truck may possibly still have the emissions/vacuum line diagram sticker on the under side of the hood?

Don't worry someone will have it and post it here for you, or email to you.

Your evap system is pretty basic but comprises of hard plastic lines and soft rubber fittings.  Neither of these last along time in the engine compartment.  The lines tend to crack and split and the fittings just rot away.

I don't know of anyplace where you can get stock Mopar plastic fuel evap lines, but you don't need that.  Any small diameter vacuum line or fuel line will work.  Vacuum would be a better choice. 

Do you still have the charcoal evap canister?  It is located on the passenger inner fender at the front behind the headlights.  You will need that.

Also a stock or stock replace gas cap.  A non original one could leak.

If you can post up some pictures of the engine compartment of your truck.


Just curious, where to you live that requires an evap test on a 25 year old truck?


Cheers

Chris
 

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Discussion Starter · #3 ·
I have the diagram under the hood, and have replaced all the lines already with new rubber tubing, had that issue resolved when I found out that they all broke. the diagram under my hood really doesn't do me much good on tracing things back. I had to go to the junk yard and pick at a fresh truck to get the diagram for all of the vacuum lines. drew that all out myself. I guess I should have been more specific on what I was trying to say earlier.

I'm trying to determine what I have to tear into (which lines to follow and replace). When they do Evap tests, what lines do they plug and pressurize? Do they just go from the canister to the tank or do they do it from other places?

I was told by different smog shops and techs that the truck is not meant to do Evap tests on because it's a open system (suppose to vent), but then again other places say that you are suppose to? i'm curious if I'm getting lied to or screwed... Any inputs?

Sadly enough I live in the great old state of California. Place is a cesspool as far as I'm concerned lol
 

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Im not sure about Cali laws.  So I have no idea what they would do for a test but I'll bet the answers are online at your DOT state site?  The canister has  line that goes to your carb.  There is a valve or port that opens on the carb allowing the engine to inhale any evap gases contained inside the charcoal canister.

I believe there is also a timer on that system so it only happens when it is warmed up?


Now as far as your system being pressurized to check that really sounds like a post '94 OBII check but I may be 100% wrong too!

the only sure way is to research exactly what test are required for your year truck.  Not unknown for these check stations to rip people off.

Good luck


Chris
 

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I agree with v737d,post '94. back in '85 the technology for a pressurized evap was'nt available then,to the best of my knowledge.in order for you to have that kind of system you would need the following parts(in no particular order and i may leave a couple out)

natural vaccum leak detection pump
onboard refuel vapor recovery
leak detection pump
of course your egr,pcv,Etc. you get the picture. most of those are controlled by the pcm to create vaccum or pressure depending on driving conditions, or whether the vehicle is off, during periodic test's etc. and in '85 that was not on these trucks.Yes,check on the web and see if you can find out any more info. on your year model.
 

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Discussion Starter · #6 ·
Thanks for your inputs, I'm surely looking more into this, I'm finding more stuff every day online that may help clarify what the hell I can do. one things at a time. Only a matter of what I may or may not have to do.
 

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As shown there should be a line that runs the same route as the fuel delivery lines right back to the sending unit assembly on the fuel tank...check the steel line for rust...then the rubber lie where it connects to the tank and possibly the vent\valve on the tank.
 

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Yup.  there is a long steel line with rubber hose on each end connecting the far ends.  The fuel pickup assembly has a nasty habit of rusting lines and the rubber hoses can decay with time.
 
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