My 2003 Buick Lesabre wont Idle after I get gas?

Question

This car runs fine until I get gas. After I fuel up it wont idle. I have to let it run with my foot half way to the floor for several minutes after which everythings fine. Ive been to the dealer 8 times and they cant fix it. Help !!!!!! I also have a " service engine soon" light that wont stay out. Everythings current and I had a $400 tuneup. this car has 29.000 miles

Answer 1

Best answer to Lee

Answer 2

You have a bad rollover valve or purge solenoid in the gas tank / emission system. When you fill the tank, raw fuel is getting in the vapor lines and into the charcoal cannister. When the purge solenoid opens to burn off the vapors, instead it gets a slug of raw fuel. That's why you have to depress the pedal to keep it running long enough to get the extra gas burned off. Once it does, everything is back to normal. The code that will be scanned by the dealer will be something like a P0455, or similar, pertaining to an emissions problem.

Answer 3

if the vacuum pressure is not registering propperly after the cap is replaced when finished filling the cap is not on tight or faulty and on newer model vehicles there is a pressure sensor on the fuel pump that sends a signal to the computer if the pressure is not to specification from the sensor a code is set in the computer replace the gas cap reset the code and that should fix your problem, but first try going atleast three clicks with the cap before replacing it if it holds idle pressure is regulated propperly if not follow advise replace cap reset code

Answer 4

Just for grins, try a new gas cap. I would almost bet that will clear the problem.
When you open the gas cap to put the gas in, you change the pressure in the tank. If the gas cap is faulty, you would have to fool with the idle by giving it more gas, until the pressure built back up.
Good luck.

Answer 5

Well at least it isnt lazy Right? ;o)