Crank sensors and ignition wires (NA, NB, NC)
A Miata that dies and will not restart, or flashes its check-engine light under load, is often a crank position sensor on the NB or a broken coil wire on an early NC. This page lists what sellers describe and what owner threads said. For the coils themselves see ignition coils. It is not a repair guide.
How to read it. Seller claims are as read on each seller's own page on 2 October 2026. Owner accounts are from Miata.net forum threads, dated below, and are individual opinions, not advice. There are no prices on this page, and nothing here was bought or tested.
| Seller | What it says it offers | Fits (as stated) |
|---|---|---|
| Moss Miata, crankshaft position sensor | described as made to match the fit and function of the original for when it has failed from heat or internal damage, so the engine computer gets proper signals | 1999-2005 NB |
| Moss Miata, NGK plug wire set | wires with EPDM insulation for heat resistance, built to carry current while resisting radio interference; there are separate options for 1990-2000 and 2001-2005 | 1990-2005 NA and NB |
| Moss Miata, ignition coil by Mazda | the NC coil, OE reference L3G2-18-100B-9U | 2006-2015 NC |
Moss's search results also show a camshaft position sensor (916-661) and Magnecor and Cobalt plug wire sets; I did not open those pages.
What owner threads said
- An NB that keeps stalling (May 2019). An owner's car died on the freeway for the second time with the check-engine light on, after a few days of slow starting. He changed the sensor in a minute at the roadside with a spare from his glovebox and a 10 mm wrench and asked why they keep dying. One reply blamed a wobbly crank pulley and said the fix is a new pulley boss and key with a blue removable thread-locker. A moderator said that if he swapped it that quickly with a 10 mm socket he may have replaced the cam position sensor and not the crank one, and said he had good results with sensors from Rock Auto, preferring the Standard or Beck brands. (Miata.net thread; first page, individual opinions.)
- A 2006 NC with 23,000 miles (August 2014). An owner's flashing check-engine light came on as he took the engine near 6,500 rpm. Replies said a flashing light means stop and read the codes, and one said it sounded like a misfire. Later in the thread posters pointed to the wiring at that coil pack and said some owners had lengthened the wires by splicing in a pigtail with the connector on the end. (Miata.net thread; first page, I did not read to the end.)
Search results for other Miata.net threads say NB owners keep a spare crank sensor in the glovebox, that a failed one is usually dead rather than intermittent, and that the early NC wiring breaks inside the insulation at the coil connector because the harness is short and Mazda changed it after 2006. I did not read those threads, so treat them as leads.
Not covered yet
- NA crank and cam angle sensors (the NA's cam angle sensor O-ring is on the oil leaks page), and a seller of NC coil harness repair parts.
- An ND owner account for any of these.
© 2026 Fischer Interactive LLC. Written for the Ref Sensor app's Miata users. The seller's page is the authority.