It could be several things but , check your catalytic converter because if it is bad it wont let your car run because the air flow is restricted and makes it appear to be something serious
As much as the gas tank will hold... ---------------------------------------------------------------------------------------------- On a 1997 Mercury Grand Marquis , the gas tank capacity is ( 20.0 U.S. gallons )
According to the 2000 Mercury Grand Marquis Owner Guide : ( The gas tank capacity is 19.0 U.S. gallons )
For a 2005 Mercury Grand Marquis : " regular " unleaded , 87 octane According to the Owner Guide
Regular Unleaded.
18 MPG.
on top of gas pedal
According to the 2004 Mercury Grand Marquis Owner Guide : ( 19.0 US. gallons )
According to the 1997 Mercury Grand Marquis Owner Guide : ( 20.0 U.S. gallons )
The ( 2007 ) Mercury Grand Marquis has a ( 19 U.S. gallon tank )
approx 20 us gallons
" regular " unleaded - 87 octane
According to my Chilton's Auto Repair manual : A ( 1987 ) Mercury Grand Marquis has a ( 20 U.S. gallon gas tank )