Immediately after I fill my 2006 Hyundai Accent with gas, the engine shudders, then dies. The only way to keep it running is to press down the accelerator and rev the engine up for a few minutes, then slowly back off. My mechanic said I need an new fuel pump, so he replaced it, but it didn’t solve anything. I still have the same problem every time I fill up. What’s causing this and did I just pay for an unnecessary fuel pump?
You need a new mechanic.
First, if you have a habit of “topping off” your gas tank (continuing after it automatically shuts off) then stop.
What you probably need is a new vent valve for the evaporative emissions systems, or you have some other issue in that system. This system captures gas fumes & sends them to the engine to be burned instead of being vented to the atmosphere. It sounds like yours is getting liquid gasoline in it rather than just vapors.
In any case, find a new mechanic - one who knows what an evap system is & how it works.
In the meantime it might help to stop short of filling the tank all the way.
When you fill up the car, do you top it off or just quit when the filler shuts off automatically?
I always stop when the pump shuts off automatically.
“I always stop when the pump shuts off automatically.” Good, that helps eliminate on set of problems.
When was the last time the air filter and the fuel filter were replaced? Do you buy your fuel at a busy station or one that does not seem to have much business?
The places I get fuel are very busy - big city, lots of people. I do regular maintenance and replace all filters when my mechanic tells me to.
If this is truly confined to only when you get gas then you are probably still looking at an evap system issue.