Topic: *Putt-Putt* from my EVAP can

[emersonwaite]

So, tried relocating my EVAP canister to below that extra tray on the drivers side of my 97 tj (cylinder evap can)

Shortened the lines, etc.

now, after running a bit, at a stop it *putts* pretty loud, and when I excellerate, it speds up till I cant tell it's doing it anymore, but I'm pretty sure it's still *putting*...just really fast.

NO IDEA WHAT"S GOING ON

felt the lines. Turns out it strongest from the sensor thing that hooks up to it. (no idea what you'd call it. it has the two vacuum lines running to it, and is hooked up to the wiring harness) it's clearly coming from that.

I should take a picture, but to explain: Relocated, and shortened lines. Otherwise, the canister is mounted vertically (tubes, etc, at the top)

does the angle of mounting matter? it used to be on an angle with the tubes at the top. didn't think it would matter if  I made it completely vertical.

the sensor has a "top" and "bottom" end...and yes, it is the right side up (now )  f....or the last couple of days

It's been relocated to allow for an air filter/intake to be mounted right  next to the intake plenum.
So trying to make this work is the goal.

Oh, and if i turn the engine off it stops the noise (figured I'd add that just in case)

thanks all. best site EVER

[sharpxmen]

most of this went over my head but just a suggestion: try to swap the lines and see what happens.

[dwtaylorpdx]

Could be the purge valve cycling?
and for some reason its noisy now?
Did you change the way it was mounted?
Maybe the noise is coming through the body?

Dave

[emersonwaite]

yeah, (sfter some research) it's the purge valve
and yeah, it was upside down for a bit.

somehow I didn't see the label "up" on it...*sigh*
saw it when I was fiddling with it. Flipped it...and it's still *putting*/ticking

Gonna replace the lines real quick, look inside, clean things, etc. (if I can...dunno if it';s a closed system)  and go from there.

stethescope and feel says it's coming from the purge valve, no question. Nothing else is making that noise, or vibrating like that.

We'll see what goes, and I'll have a few pictures as of later tomorrow.

untill then, anyone have issues with their evap canister purge valve like this?

[emersonwaite]

...oh, yeah, and I'm gonna take a run with the lines swapped too.

thanks Sharp

...it really probably is just another dumb move on my part...

we'll see

[emersonwaite]

So, swaped the lines, and it's still the same.

one of the ports even says "vac" on it...so I didn't have it wrong, in the first place.

hmmm      

(that's got to be the most used emoticon on this site)

opened up the purge solenoid thing.
there's a spring and a valve and a blah, blah, blah.
no idea what they do. Just cleaned any gunk...which was very little if any. Put them back exactly the same. closed up the cap.....and yeah. We'll see tomorrow on my drive to work.

I just don't know.

Looked on a bunch of sites, about other vehicles, even... nothing.  Nothing nothing nothing nothing

hmmm

[sharpxmen]

did you check the FSM to see what it says regarding the evap canister? never looked at that, but who knows maybe there's some info there that can help you out.

[Jeffy]

You know, I'd try putting the evap canister back and see what it does.  If it goes back to normal then you'll know it's your mounting and not the canister.

[sharpxmen]

i looked at the FSM for YJ '95 (different than yours but my guess is that the basics are the same). this is what i found (see below copy/paste from FSM). I would try firs what Jeffy said (put the canister back in it's spot). If that doesn't fix it it could be the vacuum switch inside that opens and closes so maybe it has some loss - never took one apart so i don't know how it's built but since you did look to see if there is anywhere it might lose vacuum and that can result in the valve closing and opening (maybe there's an o-ring in there or some sort of a gasket).

CANISTER OPERATION
Vacuum is used to control and operate the
EVAP canister. No electrical circuitry is used to
control or operate the EVAP system.
The EVAP canister is equipped with a vacuum controlled
purge shutoff switch (orifice) (Figs. 4 or 5)
that controls canister purge operation. The switch is
open when manifold vacuum is applied to it. When
the engine is operating, the EVAP canister purge
function draws fresh air through the top of the canister.
This causes the stored vapors to be drawn out
of the canister and into the airstream in the air
cleaner snorkel (Fig. 6).
The air cleaner contains a venturi in the air
cleaner cover used as a purge line vacuum source
(Fig. 6). The venturi effect increases the speed of the
intake air flowing by the slots in the venturi wall.
This creates a low pressure area around the slots.
When the purge shutoff switch is open, vapors from
the canister are drawn through slots and into the airstream
flowing through the venturi (Fig. 7). The vapors
pass through the intake manifold into the
engine combustion chambers where they are consumed
during engine combustion.

[emersonwaite]

yeah, been fiddling with it a bit.

Gonna put it back to normal tomorrow afternoon.
otherwise... ?

I can't "feel" any difference. It's not like it's sluggish. But what do I know, for seat o' the pants, feel.

looked at the old hard plastic tubing. There was one end, of the two tubes, that was narrowed off (small inner diameter) as if to restrict airflow. Sadly, I don't know where that end went. The other three are otherwise the same as each other (larger inner diameter). guess no one wants to check there's to let me know where that one small end goes, eh?
FSM stuff makes sense, but it's mostly a closed system. can barely open it up and mess with things, so can't do much there.

thanks...

I'll get back soon
yeah, kindda bugs me

[sharpxmen]

I can't "feel" any difference. It's not like it's sluggish. But what do I know, for seat o' the pants, feel.

you won't, it's all recirculation of the gasoline vapors (or to prevent waste by evaporation if you wish)