Doc Toro

Hi. I had tried everything, from changing the entire fuses ( including B5B4 18-811 relay) from the hood fuse box, I had changed the one under the driver side (fuel relay (B5B4 18-821), changed as well the coil, the CAM sensor and the Crankshaft sensor, and still with no spark. Would some one help me, please.

Thanks

blaen99

How are you diagnosing no spark?

sixshooter

I've heard that a broken timing belt has caused this for another Miata guy because the CAS stops giving a signal.

Does the check engine light come on when you try to crank it? Just curious.

Had you done any other work to the car before the problem arose or was this out of the blue?

Doc Toro

Thank you for your answer. At the beginning we noticed that within the coil plug was active current voltage available, this was after we rechecked all the fuses, then we took an outside spark plug hooked to one of the spark plug cable and then try to start the engine, there was no sign of any lightening or spark seen, this is how we found the problem. Then I decided to change the coil, again nothing happened. Finally I ended changing all the other parts I mentioned with no luck.

Doc Toro

That is the weird thing about, it never had turned on the check engine light. One small detail. prior to this unfortunately problem, the inside light never worked until suddenly it came on, lasted about 5 minutes, and suddenly the dash panel light, the radio and the outside fender lights went off. Then I founded that 20A fuse from the under hood fuse box had blow up. After was changed , the engine started with no problems, I even drove the car for a while, then when I turned off, is when everything started.