You can find the correct firing order for your 1987 Mercury cougar at www.coolcats.com, it is a website dedicated to the cougar and thunderbird.
it is behind the air cleaner with all the spark plug wires coming out it
Straight forward job but be careful on replacing the plugs as they are deep also remember which lead goes where
They will if it's the 3.8 L - V6 engine ( Motorcraft WR 4099 - part number ) The 4.6 L in the Mustang and Cougar take different spark plug wire sets ( Motorcraft WR 5938 for the Mustang ) ( Motorcraft WR 5935 for the Cougar ) The spark plug wire set for the Cougar has some longer wires in it )
When changing an ignition coil on a 1999 Mercury Cougar, it is very important that all of the spark plug wires are put back on exactly as they were taken off. A set of markers will help to identify what wire goes where. Take off each spark plug wire one at a time and place it in the same position on the new coil. Before taking the wires off it will help to color code them with markers.
As long as you put the spark plug wires back on the new distributor cap in the PROPER ORDER , no , it would not effect the engine timing
You fail the mention which engine, so I will assume it is a V6: Look here: http://autorepair.about.com/library/firing_orders/bl-fo-4103.htm
Your Mercury Cougar might stall in reverse because of a problem with a bad crank sensor. This problem could also be due to the crank sensor wires which are damaged or not wired correctly.
If the lightbulb itself is burnt out on a 1991 Mercury Cougar then just replace the light. If it is the wiring that is the problem then find the burnt wires and cut them. Replace them with new wiring.
Start with the ign. wires and the spark plugs.
Screwed into the engine. Follow the spark plug wires.
wires, connecters, terminals
The 1999 model, 90 hp Mercury outboard requires an NGK BUHW-2 spark plug, standard plug wires are acceptable.