Not sure if this should be in tech section but..


I was changing the spark plugs in my 94 fd. And the last shop that changed it put a Trailing spark plug where the Leading should've been. (two trailings)

(haven't pulled other two yet) and it had a little oil on the plug. The car hasn't been running for awhile and this find worried me. What should I do from here? I've no idea the consequences of that incorrect plug with oil on it.

 

Some oil on the plugs will be ok.
Just put the right plugs in the right holes, and it will be good.

 

They have 2 spark plugs to assist in the efficient fuel burn in the rather elongated combustion chamber.

Leading Plugs:

The leading spark plug is located lower in the combustion chamber than the trailing plug. The leading plug is the first to fire, which ignites most of the air-fuel mixture and provides the majority of power. However, if a rotary engine only featured leading spark plugs, incomplete combustion would likely occur, because the rotor would move into the exhaust phase before the combustion flame could reach the air-fuel mixture in the upper portion of the chamber.


Trailing Plugs:

Located higher up in the combustion chamber, the trailing spark plugs typically fire 10 to 15 degrees later in the combustion process than the leading plugs. This completes the combustion and provides a more uniform flame to power the rotation of the rotor. An easy way to remember the position of the separate spark plugs is "T" for the top, trailing plugs, and "L" for the lower, leading plug