where can I locate the pressure sensor for the fuel system and how can I tell if its bad.
OK 4.6 There is a schrader valve on the fuel rail, can't post picture it's copyrighted and will get deleted anyway. Looks just like a tire valve, get hold of a fuel pressure tester gauge and should have 35 psi minimum. If it's lower, either fuel pump, filter or regulator is bad.
Looking for a Used Grand Marquis in your area?
CarGurus has 1,784 nationwide Grand Marquis listings starting at $2,250.
Search Mercury Grand Marquis Questions
Mercury Grand Marquis Experts