Mazda Miata is missing in one cylinder

mazda
engines

#1

Hi! I have a '97 Mazda Miata MX5 that was missing. I replaced the spark plugs but it was still missing. We pulled each plug out one at a time and found that pulling out the first one made no difference to the running of the engine. The wire is ok, the plug is firing but it’s not connecting. Any suggestions?


#2

Is the missing cylinder getting fuel?


#3

Find the fuel injector for that cylinder. It is on the intake side (the side where the fresh air comes in through the throttle assembly, opposite the exhaust pipes) It is about the size of a spark plug and is attached to the fuel tube and has an electrical plug attached to it. Check that the electrical plug is attached and makes a clean connection. If the wire is connected, take a stick or a long screwdriver and use it like a stethoscope to listen to the injector while the car is running. It should make a clicking sound inside as it works. If the injector is not clicking, you are on the right track.


#4

You did not mention plug wires. That car fires the plugs twice as often as most cars so it goes through a lot of plug wires. If those are original wires it is a wonder that it runs at all. Get OEM wires (you don’t need the fancy fat or colored wires.) They don’t need to be OEM brand.


#5

“That car fires the plugs twice as often as most cars…”

Why is this so? I have a '91 Miata and I was not aware of this.


#6
  I don't recall the reason or even if there was a reason, for sparking at each rotation, while most cars only spark on the power stroke.  But that is the way at least some models of the Miata worked.  Like mine.  It does cause wear on the plugs and wires.  You don't need special wires or plugs, in fact the expensive fancy ones did not seem to last as long as the OEM quality.