Everyone breaks something on their jeep sooner or later... if you don't, then you are a mall rider. Yes, that was a gutsy move he did... lesson learned. Everyone makes mistakes off roading. A prime example are the number of folks that roll their jeeps...

He wasn't blaming anyone... he was just trying to get help on getting it fixed.

So... shut up!

 

I guess this thread is old, but I can add some info on the EVAP canister and system to help.

It contains carbon particles. Its job is to capture gas vapour from the gas tank by adsobing it into the carbon particles as the vapor passes though the carbon. The pressure from the evap can (and gas tank) is vented as non-gas containing (i.e. pollution/HC free) on the outlet of the canister to the amosphere. The hotter the day the more vapour is created in the tank - remember the old days when you could smell fuel around cars on hot summer days - they vented gas tanks straight to the atmosphere and caused more HC pollution than driving your car - hence the EVAP can was mandated/invented.

Of course problem is the can has a limited adsorbtion capacity for gas - it has to be emptied on a regular basis. The is the purpose of the purge (EVAP) valve. It is a PWM controlled valve that is like a throttle that the ECM will open tentatively to get a portion of its air when conditions are correct - it monitors how rich (i.e. gas soaked) that air is via the upstream O2 Sensor and determines how full of gas vapour the EVAP can is and hence how long it needs to keep emptying it to prevent overflow of gas vapour into the atmosphere.

Hence problem #1 - if you damage the EVAP can under water you will likely pull water into can and when the purge valve next opens you pull water vapour or water into the engine (and the engine won't like it!). Also if there is a big damage it will look like a vacuum leak (very lean on O2 sensor), but the ECM should be clever enough to recognise this and stop purging after the first try.

The tightness of the evap system from gas cap through tank through evap can through the pipework to the purge valve ( and the evap can closeure valve on its air vent side) are part of an OBD diagnostic monitor. If a leak is detected in the system (down to equiv of I believe 40thou of an inch hole - i'm rusty on detail) a DTC and check engine will illuminate unil fixed. If a gross leak (i.e. like leaving the gas cap off = 2" hole) is detected I believe you would see the "gascap" message in the odo display instead.

Hence problem #2 - if you damage the evap can you have a leak. The diag will run when conditions are correct - the smallest leak detection is actually done after you stop the engine via a pressure sensor in the fuel tank that measures pressure decay in the system over time (ie relativeley no deay = good, slow decay = minor leak, quick decay = major leak).

Hope this helps understand what the evap system and purge vlve and evap vent valve and fuel tank pressure sensor are for.

 

Foxcasper you are awesome. Thanks for the detailed info. In my case, I know my evap can was not only broken, but had soaked up water like a sponge. When I swapped in the new one, the broken one I was taking off literally weighed 5 or 6 times the new. It makes sense that I just sucked in some of that water.

The only thing strange to me, is that I didnt have this cutting out issue even when I still had the water logged can on there. In fact, it was a couple of weeks after I put on the replacement that it first did it. Coincidentally, that was on the tail end of a 6 hour road trip at 75+ mph, too. It did it on my way out there, when I got to the end of the trip. Sat overnight, no more probs. Then it did it again when I returned home, right at the end of that same 6 hour trip. Honestly, it felt like my Jeep was "programmed" for the fuel/air it needed running constantly at that speed, but choked out like my mixture was wrong only when I floored it.

Here again, running around town, it hasnt happened since that trip... and I havent changed anything other than running a tank of premium gas through it once, and then also trying the fuel injector cleaner. Not sure if one of those helped, or its just coincidental. I have to say that I am surprised that the hoses were just press fit onto those nipples considering it is such a sensitive system under vacuum. I am going to check all of those connections... If it happens again, I may look into this sensor.

Hey, thanks again for the info!

 

You would be more correct if you had said, no IMMEDIATE issues. Unless every electrical connection is completely waterproofed you will eventually get a corroded connection in the coming months and not know why your Jeep is acting strange. These vehicles are Jeeps, not submarines.

 

Sorry to hear about your problem..I have experienced the exact same thing you have. I believe that the chevron I got my gas from had some water in the gas since I got a 1/4 of a tank 93 octane(I run superchips flashpaq). Anyways after I pumped the gas I was going down the road and the engine would bog down, ESP light would come on and the jeep would steer to the side and slow down. I figured it was bad fuel so I put the Flashpaq back to factory settings just to be safe. Anyways, I bought more 93 octane from a DIFFERENT gas station to dilute the water enough to make it to local auto store to get the Iso-Heet and treat the gas. I then filled her up with 93 all the way. I hope your problem got solved if not goodluck to you.

 

holy thread revival, batman!