Date Added: Tuesday 21 July, 2009
I, like other people found that my Mx 5 stopped firing on two cylinders in this case 4 and 1 (when you're looking at the coils, 4 and 1 are on the left-hand side). Taking the coils off is a bit fiddly. However, after undoing the two 12 mm bolts I used a small pair of mole grips to get the spade connectors off. Then with my multi-meter I checked the 'good side' (cylinders 2 and 3) and found I had a resistance of about 8 - 10k ohms(?) testing between the separate pin (one on the far right within the 3 pin enclosure) and one of the two pins close to each other. Then about 48 - 50k ohms(?) on the other pin using the separate pin as a common. I'm not sure if that is the specification by Mazda, but you have to go be what you have.
In reality if you get some kind of reading from the 'good' coil side and the faulty coil is not measuring the same you know your onto 'proving' there's is a definite fault. Now that I had a comparison, I checked the pins for cylinders 4 and 1 and found the primary coil 'open circuit', in other words no reading at all. What caused this I have no idea.
It took me about 5 minutes to re-assemble the coil pack back into the car and to my pleasure my T reg MX 5 MK2 is now running again on all 4 cylinders.
Rating: [5 of 5 Stars!]