I think if you replace that and check your vents as already mentioned, you should have some success. Mine is a 2wd ans as such does not see the dirt that a w series sees.

Good Luck

 

If you live anywhere like Kentucky, dirt-daubers will plug them, and any other orifice, quicker than you can clean things out.

I have actually had them build a big mud house, in only a couple of days, over a throttle-linkage, such that it had to be busted off before the accelerator pedal would work.

 

my 90 d250 had the tank almost completely sucked in on a trip I took this summer, I had about 400kms on the tank and it was saying I still had over 1/2 left so I stopped to fuel up just in case and looked under the truck and she was sucked in tight. Needless to say I loosened the cap and it started to come back, filled her with fuel and kept trucking with the cap loose till I could get a new one.

Next town I bought a new cap but that didn't help, still sucked in the next tank on a long haul... Seems I am ok on the short trips but the long trips it won't make it.

I guess I am going to have to try to find that breather hose and see if it is plugged up....