Gunk in the sleeve... bet its been sprayed with CRC or similar

Just make sure the eos is closing and opening properly and check that it is not badly pitted or worn out. There is no harm in replacing the eos at the same time as the coil. also make sure the yellow capacitor is soldered on properly also, this capacitor helps to extend the life of the eos.

And +1 on retropin's comment, could just be full of gunk.