AboutMp2 Expertise I prefer to answer questions relating to the Miata since this has been my area of specific
expertise since 1991. I can answer questions relating to the other Mazda models however
some limitation of expertise may reduce my accuracy.
Experience Mazda technician since 1987, shop owner and specialty are regarding the Miata since 1991 covering mechanical, electrical, trim and body. Specializing specifically in drivability concerns.GKHS 1985, BVC 1987, MNA 1989, ASE Master Technician Mechanical 1995, ASE Master Body/Paint/Collision 1996
Education/Credentials GKHS 1985, BVC 1987, MNA 1989, ASE Master Technician Mechanical 1995, ASE Master Body/Paint/Collision 1996
Question Hi, I am lost with this problem. 1996 miata 1.8, died on highway. While there are 2 coils, only 1 is firing. Checked coils resistance and they checked ok. Swapped electrical plugs and the non working coil fired! (1&4) Checked wiring and all looks good. Could this be a ECU problem? Thanks.
Answer In all likelihood your crank angle sensor (CAS) has failed. Yours may or may not also have a magnetic pick up located at the front of the crankshaft pulley, 1996 was a transition year some had both some only had the CAS (depends on the production date). Some diagnostics could be done to narrow and confirm the sensor failure versus a coil or harness failure. The ECU looks to the CAS to determine the "G" signal (top dead center) TDC of #1 and the "Ne" signal 180 degree rotation therefor a resulting failure would cause fire on 1&4 and no fire on 2&3.
