Help!!! Gas tank back pressure!???!??

[Fishy]

One of the biggest causes on the 100 is overfilling and then sloshing that fuel around. Once the pump shuts off, don't give it that extra splash of fuel.

I've always heard that once the charcoal gets wet, it will not dry out. However, I went about a year without filling up all the way and my problem is hardly noticeable anymore. I filled to about 3/4's or just above for a long time.

The 03+ 100 series has the shoebox-style canister (located above where the spare tire would sit). That vacuum valve goes bad too and the only way to replace it, is to replace the entire canister. $400+ if you can get a deal. $500+ if you're paying retail. I've seen gas literally squirting out of the cap on some vehicles. If you're going to purge it, go super slow. If you just open the cap all the way, you'll get the gas face for sure.

 

[nuclearlemon]

my issues on the marshmallow ended when i changed the charcoal canister and stopped "topping off" my tank.

 

[nnnnnate]

Bringing this one back from the dead to ask a follow up question.

History:
2007 LX470 with 114k miles.
This happened to me for the 3rd time at CM last week in the swell. Previous two instances were after a steep climb in heat with a relatively full fuel tank. The first two instances I had shut off the engine then tried to restart unsuccessfully, it would crank but not fire. Sitting for 15-20 minutes resolved the issue. Last week I was on I-70 heading back to camp and the engine on my LX470 shut off. I pulled over, remembered my past issues and waited a for a bit and it restarted. At the time I had about half a tank of fuel.

Question:
Understanding the issue as described previously in this thread with the fuel vapor and pressure of the system wanting to vent, what is keeping the engine from firing when the high vapor pressure is present? Is the fuel actually boiling in the lines as it exits the fuel tank on its way to the engine? Is this "vapor lock"?

I'll be the first to admit I'm not super mechanical or technical but I'd like to understand the underlying issue better. I feel like I understand why the vapor pressure is building but I still don't understand how that causes the no start or shut down of a running engine.

Thanks.

 

[LARGEONE]

I changed the charcoal canister on my 80 to an aftermarket one (~$40) and it worked great for a few years. But, I'm back lots of vapor at altitude now. No issues with the truck running, but i get tired of smelling the gas when I'm above treeline.

 

[Corbet]

I don't have any issues with ethanol free fuel. And I'm lucky we have 3 different locations in Durango so locally I'm always running it. With 10% blend I've had the same eruption as Treeroot's previously posted indepentant film. On trips I try now to fill my tank in the mornings and hope I don't need to again that day. Then deal with the stink.