Look what I found! Whats it for?

Haleyrz · 09-27-2009, 09:47 PM

Ok, so I've been investigating a little bit on the typical cruise control problems. I've found so many possibilities. My problem is that no lights come on when you push set, nothing. I read that it could be the switches in the colum, could be vacuum, could be could be could be. So I was snooping around my vacuum lines and found one just sitting there, completely off. I have no codes other than my Bad TCM and Tranny range sensor (NSS) which i've cleaned and things work fine, but codes are still there. So what is this and what would it affect? I connected it back and cruise still doesn't come on (since im not sure what it is i figured i'd give cruise a shot). The jeep doesn't seem to drive funny, and no high idle....so I didn't notice it until today just looking around.

XJcrazy00 · 09-27-2009, 10:18 PM

I'm guessing the airbag light isn't on, you'd probably mention that right?

If so, clockspring in the column.

Haleyrz · 09-27-2009, 10:25 PM

no air bag light on. I'll check out the clock spring, thanks. As far as my picture goes......what is that canister, and vacuum lines for?

Justin123 · 09-27-2009, 10:35 PM

that is a charcoal canister. it basically stores the un burned portions of fuel in the exhaust, then they re-enter through the intake manifold with the air. it's not that important, but it affects gas mileage. keep it connected.

Haleyrz · 09-27-2009, 10:50 PM

Ok that makes sense. Can you blow that line off? I guess i'm just curious as to why it was off, lol. Thanks though!

Justin123 · 09-27-2009, 11:23 PM

Um.........? it should be fairly tight. maybe if there was supposed to be a spring clamp on the hose and it broke or fell off, the hose could slip off. im not sure how much pressure is in the canister, but seeing as how it is plastic, it can't be much. i would clean off the hose mount and the inside of the hose with a rag and re install it. maybe even put a small hose clamp on it if you have one laying around. I will check my jeep to see if there is supposed to be some kind of clamp in place.

Haleyrz · 09-27-2009, 11:34 PM

Hmm...yeah. My roommate has a 98 dakota. He said his fell off once, that the rubber boots on those canisters can vibrate off? Probably what happened. It went on snugly so I'm not too concerned about it. My mpg has been somewhat crappy for a stock xj...maybe this will help.

Justin123 · 09-27-2009, 11:39 PM

hope it works. nobody can afford to have below average gas mileage for a cherokee. haha

FISTFULL · 09-28-2009, 05:46 PM

Typically, the EVAP system only is only carrying about 1 psi. But, it can definately cause a CEL. While you may not have it currently, it probably would have only been a matter of time.

dilligaf69 · 09-29-2009, 01:53 AM

The charcoal canister collects excess gas fumes from the fuel tank, does not in any way have anything to do with the exhaust. One line usually has either constant vacuum or switched vacuum to a diaphram valve on the canister. When you start up the vehicle, the canister will release any contained fumes into the intake. This is just another stupid idea by the tree huggers from back in the early 70's to make excuses to save the planet from all the bad killer gas fumes in the world. It does not affect your gas mileage unless the actual vacuum line is disconnected or leaking. if it is you will have issues in drivability and on newer vehicles check engine lights going off.

Haleyrz · 09-29-2009, 04:30 PM

Quote:

Originally Posted by dilligaf69

The charcoal canister collects excess gas fumes from the fuel tank, does not in any way have anything to do with the exhaust. One line usually has either constant vacuum or switched vacuum to a diaphram valve on the canister. When you start up the vehicle, the canister will release any contained fumes into the intake. This is just another stupid idea by the tree huggers from back in the early 70's to make excuses to save the planet from all the bad killer gas fumes in the world. It does not affect your gas mileage unless the actual vacuum line is disconnected or leaking. if it is you will have issues in drivability and on newer vehicles check engine lights going off.

Yeah, seems like that one line that had fallen off isn't that critical......drives the same as it did without it on there. Thanks to everyone who replied. Case closed on the charcoal canister. Now onto the cruise control. Um, I know the clock spring is located on the steering column. Anyone have a picture of spring/switches in there, or a diagram?

KamekLocked · 09-29-2009, 05:37 PM

Actaully it is for the containment of fuel vapours in the fuel system to be later burnt in the engine when the correct conditions are met. A engine at operating temp., etc. Then PCM cycles the purge control solenoid valve. It does not purge the canister at engine startup. Just some clarification.

edit:looking for the wiring diagram and a pricture of the clock spring I used to have.