A blockage in the purge line will not cause problems filling up.

If the pump keeps clicking off while filling (or only takes fuel at slow pumping speed) the problem is likely the charcoal canister and/or vent valve are plugged up (or the pump itself, but I’m guessing you don’t fill up at the same pump every time).

Below is an illustration of the EVAP system. It’s not exactly like yours but it’s the same basic concept/operation.

Parts are as follows:

2) Purge valve
3) Canister
13) Vent valve

 

allright thanks all, I got the diagram and that is what I figured. I am almost thinking it would be worth a shot to shoot compressed air through the line that connects up to the charcoal cannister. Any blockage would go into the fuel tank. I know this isn't ideal, but it would only makes sense the blockage would be somewhere else and probably in that line. it might only take a quick blast, and voila, problem solved.

It does appear that one of the PO's DID hit the frame enough to bend it just near the fuel tank. Maybe he hit a rock? fuel tank looks fine, but if enough SHOCK was there, could that knock a sensor or something out of whack? What else could cause a blockage other than evap cannister or solenoid (air was coming out, they weren't blocked. )

on the note of sensors, can blasting compressed air through evap lines damage them?

 

I’m not familiar with the vent/evaporator line setup on these, but on my old Ram 2500, when I had problems gassing it up, it was a ball check valve in the vent line from the top of the tank that caused the problem. I fixed by spraying penetrating oil through the vent line then alternating vacuum and pressure on that line until the check ball finally broke loose. I figure the steel ball in the check valve probably rusted from water/alcohol in the fuel and stuck closed.

 

Hey so I went to refuel at a different station with a tank that was 85 % full. I didn't have any problems with the $15 I put in there. IT was a nicer station, the one I usually go to has the WORST gas pumps. So maybe it's just because I go to gas stations with crap pumps? Usually the absolute cheapest stations have pumps that are just falling apart. OR is it just me noticing that?

THis problem only occurs intermittently, making me think the van just doesn't like certain pumps. But then again I guess an evap blockage would build over time if it was due to carbon? I didn't see any pellets in the lines though. If there was a steel ball, would cause a complete blockage or partial? Has anybody here ever had, or heard of, a partial blockage? My problem at the pumps doesn't always happen, just rarely and occasionally, like the other day.

I guess the next thing to do would be to test the purge solenoid, and remove the filler neck looking for obstructions. Then get family to bring a shop vac and hit that one evap line that comes INTO the cannister from the gas tank. FAiling that, I think a leak is more probable and the difficult occasional fill can be cracked up to back pressure and crap pumps at cheap stations. seriously anybody else have problems at cheap stations or it just me?

Smoke is the next step after all this.

 

In town I always buy gas at the Walmart down the street from me. Never had a problem there.

Last year I was regularly traveling about 250 miles one way and stopping for gas at the same station every time. Once in a while I would have a slight problem there. If I pulled the nozzle out a bit it would usually pump. Their prices were cheap but it was a nice, well maintained truckstop chain so there was nothing crappy about it.

I think it's just a matter of how sensitive the pumps are. It could be that as the pumps wear out the default is that they get more sensitive rather than less. That would make sense from a design safety perspective. Better to have one not pump than overfill and spit gas out.

 

That will cause an instantaneous fire. The fumes will get pulled into the vac motor and the arc from the brushes will ignite them.

I think the next step is to go to a shop because you don’t seem to have the knowledge, skill set, or common sense to work safely around the fuel system.

You, or someone foolish enough to help you, is going to get seriously hurt.

 

no shop vac then. Unfortunatley, there aren't any good mechanics out here. I am on my own.

 

I was back at testing the system. It was really easy for me to access the purge solenoid so I tested it. I disconnected the end that connects to the charcoal cannister and ran the vehicle. I did this when the vehicle was cold. I went and felt the solenoid for vaccuum and there was none. I allowed the vehicle to get to operating temperature. Then I went back to feel for vaccuum from the purge solenoid and it was strong and there, a steady on off pulse of vaccum. So that rules out the purge solenoid. I also went underneath and sprayed soapy water on all connectors for the evap system, as well as the fuel lines I could see, while the vehicle was running. I did not see any bubbles escaping. I believe the fuel tank should be pressurized quite a bit more than 1 PSI when it is running correct? In any case I was also capturing live DATA from the OBD2 system with my $30 tool. I believe this data is correct but take it with a grain of salt. I also just cleared all my codes before when I was changing the water pump, because I ran the system before installing the fan shroud and didn't have the air intake completely assembled so it threw an error codes for the MAF sensor since it wasn't detecting air flow. I just wanted to make sure there were no leaks before the PITA job of putting in the shroud and potentially gouging my new chinese radiator fins. Anyways, oddly enough when I disconnected the purge valve from the system no MIL was thrown up. not sure if that is a red flag or not. I might just replace the vent solenoid because it's so cheap, and the lines to it were filled with grey, it's old and maybe the filter has just had enough. I also have no way to know if it's partially clogged or not.

Anyways, can any of you guys help me make sense of this DATA? what are the values suppose to be for the express? ALSO REMEMBER I JUST CLEARED THE CODES SO LTFB might not be correct, which would mean the STFB would be thrown off. Correct?

And yeah I am thinking about getting the cheap smoke machine, but still worried it won't do a lick of good since the leak might be so small, and it could possibly be coming from the fuel pump area in all honestly. That is the one area I cannot see.

 

anybody have any idea about what I posted above? I went underneath the vehicle with a small mirror to find the fuel pump assy. it is near the front of the tank no? I went underneath with the vehicle running to see if it was a pin hole leak there, but I couldn't see any fuel leaking out. good thing it was a cold start because my arms were touching the exhaust lol.