Testing the Ford Coil Packs on the 1.9L and 2.0L Ford, Mercury and Mazda equipped cars is pretty easy. This article will walk you thru’ the whole diagnostic/troubleshooting process to find out what’s causing your car to Misfire. This article covers the two incarnations of the Ford Coil Pack for four cylinder engines. One is the early type and the other is the late type design. Although they are not interchangeable (since their connectors are different), they are tested in the same way. To see examples of the two styles, see the photos in the image viewer. Symptoms of a BAD Ford Coil Pack