CVO 10/29/20131.Did the fuel filter was changed ? The filter might clog up .
2.Check the FUEL SYSTEM PRESSURE
1999 Buick Lesabre 3.8L SFI OHV 6cyl
The Fuel System Pressure
48-55 PSI (Pounds per Square Inch)Position the ignition switch and the A/C system in the off position. Install a fuel pressure gauge to the vehicles fuel rail or fuel pressure test port.Confirm that no leaks are present, and visually verify the PSI reading on the gauge with the ignition in the on position.
HouseCallAuto 10/29/2013Replace the Canister Vent Solenoid/Valve