Okay I have quite a dilema with my Mazda 3s 2005. A few weeks ago I went to the pump to fill up my car which was empty and the car would not take gas. I can only put gas into take in about 10 cent increments before the pump shuts off. If I keep trying to pump gas will come back out of the filler tube. Have tried several gas stations and moving hose in all directions. One day it was warmer out and I was able to fill tank but unable to fill tank 2 days later so I dont think the hose is damged. I removed a filter canister looking thing from the rear passanger side wheel well and blew it out with compressed air it was all gunked up. Gas went in when I pumped that night. Car was in a heated garage though so that may have been why it pumped last night. Will try again today after its been out in the cold. Could this have been the problem? I dont even know what that filter canister is or what it does just looked dirty so I cleaned it. Does anyone know what that part is, what it does and if this could have caused this problem? any other suggestions appreciated. Lots of forums with other people having same issue on other vehicles but no suggestions on how to fix it. If this does the trick I will forward info to other people in desperate need of help. Thanks

 

Just a quick question, did this just suddenly happen one day and keep happening or was it something that started happening more and more over time? By the way I read your post, it sounds like it happened just all of a sudden.

 

So let me try and provide some information even though I don't know the whole story, or exactly how your car works.

The way gas nozzles click off is when your tank nears full, the fumes and air start coming back out of the fill hole, the nozzle has holes in the spout which allow this movement of air and fuel to trigger a latch that kicks the fuel flow off.

Your fuel tank vents through a filter, so if this vent is at all blocked, it will cause the air being displaced by fuel to rush out of the fill hole instead of through the vent tube, causing the nozzle to kick off. A lot of times this vent hose gets old and cracks, blocking the fumes from easily escaping. Check all vent lines, see if it got pinched or if it's just old and cracked.

Other obvious things to check are blockages, things shoved down your fill tube, damage to the fuel tube, and so on.

 

This began suddenly one morning. It was fine two days before when I gased up. has been ongoing for about 3 weeks. some days it takes gas better than others by that I mean it takes me 20 minutes to get a half tank as opposed to 30. I basically have to pump extremely slow in order to prevent gas from coming back out. There was one day where it took gas like normal and then went back to denying gas the next time I filled up. Fuel lines look fine no cracking that I can see. The only thing that looked clogged up was the filter canister that I cleaned out which was in the rear wheel well. Still trying to figure out if this filter sucks in air or releases air and if it has anything to do with the problem.

 

I don't know where the filter is for your fuel tank vent, but usually cars use a charcole filter, so if a bunch of black stuff came out of this filter... that would be the charcole. Which would mean, most likely that it was your fuel vent filter.

 

There was no charcoal in the canister only a filter that looked like this. the canister is plastic with venting holes in the bottom and top and one vent hose coming out the top witch appears to head towards the gas tank. from what i have read charcoal canisters have several hoses going to them.

 

That's looking like a fuel filter. I don't think that would have anything to do with your tank not filling up.

 

I dont think it is a fuel filter. Fuel filter I believe would be encased with no holes. This filter is exposed to air via ported holes in the top and bottom of casing. Doesnt make sense to be a fuel filter there would be fuel leaking out of those holes. filter also did not smell like gas. Thanks for your help cadmando18. Ive looked all over online and cant find anything that looks like it which has me scratching my head as to what the hell it is.

 

Yeah if that filter wasn't in a hard case it very well could be the vent filter. Get a new one, put it in, and make sure all the hoses leading to it are clear and clean. I wish I could help you more,

 

Thanks for your input