2002 E430 slow fueling
 

Hello all,
When I try to fill the car it won't take the fuel but very slowly. I have tried different stations but I think it is some kind of a filter problem in the fuel neck. Any ideas? Thanks

Was the problem sudden or slowly getting worse?

Years ago I had a customer with a Buick that suddenly stopped taking fuel, turns out there was a gas pump certification sticker blocking the fuel fill roll over valve. ( the sticker was folded to fit in the gas nozzle and they were the next unlucky customer. )

Fuel flows in the large hose and air out the small hose. When the tank is full, fuel burps up the small hose triggering the shut off. If either hose is blocked, fuel will backup and trigger the nozzle.

Does your area have special gas pump vapor recovery systems?

This is a problem with the charcoal canister getting flooded with liquid fuel or the vent valve in the system siezing.

The entire unit is in the right rear wheel well on the aft side.

Does your car flash the low reserve fuel lamp?

believe I've read the problem on another forum,and the Guy cleaned out his vent hose for the tank

I had a MB with this problem, similar vintage but I think was an S class. There is a sort of flap which cuts off fuel in the event of a rollover (mechanically blocks the filler neck with a flap), IRRC there is a weight that should have been on this mechanism but was missing so the fuel flow would make the flapper shut. Hope this helps.

!? Where is the weight?
 

Gilly, I also have this problem on my 03 E320, fuel refilling ALWAYS clicks off constantly! I have heard that it's probably my "vent" that's plugged up - something to do with vapor recovery (protecting the ozone) on the fuel pump handle (gas station pump).

So my question is... if there was a weight on this S-class' mechanism, where is the weight then... at the bottom of the gas tank?? I ask because in addition to the fuel refilling issue, I periodically get nothing when I give anything more than a quarter throttle (fuel pump & filter have been replaced, new plugs and wires, air filter good, used plenty of high quality injector/fuel system cleaner) and am probably "reaching" here but wondering if this weight might be in the bottom of my fuel tank plugging the line periodically!? :eek:

David, no the flapper is on the filler neck, so if you can get some trunk trim out of the way hopefully you can see it if your car has it. The weight is on the top of the neck if it is there, you can imagine the car rolling upside down, the weight then falls upward (would be downward if the car was rolled), which pulls the flap shut, makes sense when you see it. I don't think it is a tight seal if it shuts, just enough to slow the flow in the unlikely event the car is rolled with no fuel cap in place or if the top of the neck would be damaged in a wreck, again I think the car I was working on was a 220 chassis S class. Could not get it to take any fuel at all really.

Gilly, cool thanks... I knew it was far-fetched... but thanks for the verification.