[Steve84]

I have an 04 Lt trailblazer when I go to put fuel in it you can hear the pressure build and then it “burps” fuel back out I’ve checked the filler lines and the filter on the tank with the sponge in it was packed with dirt has been blown out this all started trying to get it to take fuel it spends 90 percent of its time in gravel roads.

 

[chem_man]

Welcome to the Forum!

OK on the burping fuel. Have you connected an OBDII code reader/live data scanner to see what codes are present? Is the Check Engine Light/Service Engine Soon/Malfunction Indicator Light illuminated?

You likely have a restriction in the EVAP system and it does not allow vapors and air to freely move about the system as gasoline flows in. You did get a start when you cleaned the small sponge filter. That is the charcoal vent valve filter that is supposed to stop dirt and small rocks from getting into the charcoal canister when it is being cleared of accumulated fuel fumes.

If I had to guess, whenever you get gas (or should I say when you used to get gas), you also topped it off rather than stopping when the nozzle tripped and stopped the flow. Am I correct? I used to do that myself until I wound up changing the charcoal canister on one of our vehicles because it was saturated with raw gasoline and there was now way it could ever release it while driving, so I changed it out.

My advice is to remove the EVAP hoses and blow them clear with air to clear them out. To go any further than that requires knowing what OBDII codes are present.

Good Luck!