Car having trouble starting-2006 VW Jetta

Hello, i have a 2006 VW Jetta 2.5. everytime i fill up the car all the way, i have this problem with it. i go to start the car and it wont start, i hear the engine turning, but it wont start, but if i wait for 5 mins and then try to start, it starts up and I dont have any issues with it after that… If i fill up my car a little bit , i dont have this problem. only when i fill up the tank all the way, it gives me this trouble. anyone have an idea/explanation for what is going on and what is wrong with the car? please let me know.

Do you “top-off” the tank, or stop when the nozzle first shuts off? If you top off, you will have damaged the system that recovers the gasoline fumes.

Try loosening the gas cap and see if it starts then.

Is the check engine light on?

No I don’t top of the tank and yes the check engine light is on and says some code related to the catalytic converter

What is the code number? If there is more than one code, post all of them.

The cat code might be a result by whatever’s causing the no-start when the gas tank is full. As mentioned above, good idea to post the exact codes here, as some folks who read this posting are pro mechanics – I’m not, just a diyer’s – but they’ll have experience with what those codes mean and what to do about them.

Also I concur with the poster above, next time it happens when the tank is full, see if it will start up ok with the gas cap loosened. Be aware this may turn on the CEL, but its a good way to diagnose if a vacuum is forming in the air above the gas in tank, preventing the fuel pump from delivering fuel to the engine. As you drive gas in the tank is used so air must enter the tank to prevent a vacuum forming. . There are various valves in the tank and fuel system that is supposed to prevent this from happening, but those are fairly common failure items as reported here. If that was the problem, it would be worse when the tank is full b/c there’s less air in the tank already, so a vacuum would form faster.

One question: Does this no-start problem happen immediately after filling the tank? I mean you go to the gas station, fill the car’s tank with gas, then it won’t start when you try to start the car to leave the gas station? If so, the above idea would need some re-thinking. Since if the engine won’t start, there’s no way for the gas in the tank to get used up. I suppose there could be some kind of process where just filling the tank could result in a vacuum though, perhaps b/c the gasoline is cold.

You need to have the computer scanned for codes.

For example, if there’s a problem with purge control solenoid valve in the EVAP system, and you’re filling the gas tank, the fuel vapors from the tank are forced into the engine. Then when you go to start the engine after refueling, not only do you have the vapors from the tank in the intake, but the fuel injectors are also adding fuel.

This results in a flooded condition and the engine is hard to start.

The next time this happens after refueling the vehicle, hold gas pedal to the floor. This tells the computer that you want to start the engine in the flooded mode. This will cut the fuel injector pulse widths in half.

If the engine starts when doing this, have the EVAP system inspected.

Tester