96 grand marquis rough idle, lossof power while driving, check engine light flashes

Sounds like a bad alternator. You can bring it to most car parts stores and they will check it for you.

Your check engine light is on because your computer has detected a problem. You can take it to Autozone and they will scan it for free. They will tell you what the problem is and what you need to do. Other part stores offer the same service.

Sounds like a vacuum leak or a dirty pcv valve.

FORD: 1995-96 CONTOUR, CROWN VICTORIA, ESCORT, TAURUS, THUNDERBIRD
1996 MUSTANG LINCOLN-MERCURY: 1995-96 CONTINENTAL, COUGAR, GRAND MARQUIS, MARK VIII, MYSTIQUE, SABLE, TOWN CAR, TRACER LIGHT TRUCK: 1995-96 AEROSTAR, BRONCO, ECONOLINE, F-150-350 SERIES, RANGER, WINDSTAR
1996 EXPLORER This TSB article is being republished in its entirety to include the 1995 4.6L Thunderbird/Cougar. ISSUE: After a 1-4 hour engine soak time, long crank times and/or long crank to start followed by a stall may occur on some vehicles. No further stalling or rough idle will occur after the engine is running. The long crank and/or stall may be due to the Idle Air Control (IAC) Valve sticking.
ACTION: Replace the IAC Valve with a revised IAC Valve if no Diagnostic Trouble Codes (DTCs) are present. Refer to the following Service Procedure for details.
SERVICE PROCEDURE

1. Perform normal diagnostics and correct any DTCs as required by referring to the appropriate year Powertrain Control/Emissions Diagnosis (PC/ED) Service Manual.
2. If no codes are present, replace the IAC Valve by referring to the appropriate model/year Service Manual, Section 03-14. Refer to the following Idle Air Control Valve Application Chart for proper IAC usage.
   
   IDLE AIR CONTROL VALVE APPLICATION CHART Model Year Vehicle Engine Revised Part Number PASSENGER CARS 1995 Escort/Tracer 1.9L F5DZ-9F715-BA 1996 Escort/Tracer 1.9L F6CZ-9F715-BB 1995 Contour/Mystique 2.5L F5RZ-9F715-AB 1996 Contour/Mystique 2.5L F6RZ-9F715-AA 1996 Taurus/Sable 3.0L 4-Valve F5DZ-9F715-DA 1995 Taurus/Sable 3.0L 2-Valve F5DZ-9F715-EA 1996 Taurus/Sable 3.0L 2-Valve F6DZ-9F715-DA 1995 Taurus SHO 3.2L F6DZ-9F715-CA 1996 Taurus SHO 3.4L F6LZ-9F715-AC 1995 Taurus/Sable 3.8L F68Z-9F715-EA 1995 Crown Victoria/Grand Marquis/Town Car 4.6L 2-Valve F5PZ-9F715-AA 1996 Crown Victoria/Grand Marquis/Town Car/Mustang 4.6L 2-Valve F6AZ-9F715-EB 1996 Mustang 4.6L 4-Valve F65Z-9F715-BC 1995-96 Continental 4.6L 4-Valve F5OZ-9F715-AB 1995 Mark VIII 4.6L 4-Valve F3LZ-9F715-AA 1996 Mark VIII 4.6L 4-Valve F6LZ-9F715-AC 1995 Thunderbird/Cougar 4.6L 2-Valve F5PZ-9F715-AA 1996 Thunderbird/Cougar 4.6L 2-Valve F6AZ-9F715-EB LIGHT TRUCKS 1995-96 Ranger 2.3L F5OZ-9F715-AB 1995-96 Ranger 3.0L F67Z-9F715-AA 1995 Aerostar 3.0L F68Z-9F715-DA 1996 Aerostar 3.0L F69Z-9F715-AA 1995-96 Windstar 3.0L F68Z-9F715-DA 1995 Windstar 3.8L F68Z-9F715-EA 1996 Windstar 3.8L F68Z-9F715-CB 1995-96 Econoline/F-150-350 Series/Bronco 4.9L F68Z-9F715-EA 1996 Explorer 5.0L F67Z-9F715-BA

i would first change the fuel filter with it being run low in fuel it may have picked up some trash off the bottom of the tank so change the fuel filter and see if it runs better

Service Engine light came on and stays on and this is on my 1995 Grand Marquis LS 4.6 litre Engine. It is now idling a little rough

It may be a leaky injector. The injector is connected to the bank. 1 of 2 fuel rails.

I have a grand Marquis and I experience the same problem. If your check engine light is on I can assume your problem is there is dust in the air intake. When I ever experience the problem I take the air filter out and blow out the chamber, or vacum it out with a shop vac. If your check engine is on disconnect the battery for 5 minutes and reconnect. Then drive it. That should fix it.

Replace your spark plugs, and make sure all spark plug leads are fitted correctly.

check your transmission fluid,the motor will stall when fluid is low