1995 Lincoln Town Car

Engine Performance problem
1995 Lincoln Town Car V8 Two Wheel Drive Automatic 120000 miles

I have a 95 Lincoln Town Car. A couple of weeks ago, my car started running terrible. A friend suggested I change my fuel filter. I got the filter and before I put it on, the check engine light came on. Ok, I change the filter and hook up the diagnostic machine and it gives me the error " misfire on cylinder 5". I reset the codes so that it will take away the check engine light. The car runs great for about 1 or 2 days until the check engine light comes on again. I hook it back up to the diagnostic machine and it gives me the same code " engine misfire on cylinder 5". My cousin suggest I replace the coil for number 5 which is on the drivers side. After replacing the coil, the car still runs the same. I think I will try the spark plug or plug wire next, but I have heard that there is a special way to take the spark plugs out of this kind of engine. Is there a certain procedure to change the plugs (get the engine hot first) and do you think that this could be the problem or is there another suggestion?
April 6, 2008.

A bad plug or wire can cause the missfire, last tune up was? Remove the plugs with the engine cold. Apply a small bit of anti-sieze compound to the threads of the new plugs. Also grab a noid light and check the injector. Measure the resistance and compare your reading with the other injectors.

Apr 6, 2008.