I have a 1997 NA and have unfortunately made the mistake of assuming I could only run an NB crank position sensor in addition to the stock cam angle sensor without modifications. I do not want to modify the CAS as i want to be able to revert back to it in case. Would it be possible to use the NB cam sensor on the front of the intake cam (will buy the appropriate gear) and use that in conjunction with the crankshaft sensor? This will leave the NA CAS untouched, will leave it unplugged and add a harness to connect to the new NB sensors.

I will be running an standalone ECU with a 36-2 trigger wheel.

Thanks

 

Yes, with a BP4W valve cover and cam gear that will work fine. If you are using a pnp ECU/adapter harness I believe they expect the CAS to be modified, so you’ll want to splice the NB cam sensor into the appropriate wires on the body side of the CAS connector to route the cam sensor signal to the correct ecu pins.

Also, being a 1.8 your car already has a crank sensor, you should be able to just add the protege 36-2 wheel to it and be good to go.

Alternatively you can run it with batch injection and wasted spark solely off the crank trigger. Little less efficient but it will run fine.

 

Just buy the correct female/male 4pin sumitomo connecters and crimp an adapter harness. To revert you just unplug your adapter harness.

 

This only works with the 99+ NB crank position sensor. Not the NA one. Same question popped up recently:

https://www.miataturbo.net/megasquir...-8-car-109992/

 

Ahh ok, I’ve never messed with an BPs on standalones. Good to know

 

The replies are very much appreciated, I have purchased a 99-00 valve cover and the cam gear. I will make a harness to split to the two sensors and extend the wiring from the CAS.