trd101se

managed to get the CEL pull up and working. thank you once again guys and have an wonderful weekend.

update on today progress, koracing, following your pointers, traced and found there is no wire in #37 in my miata, so I tested #50 assigned Aux3 in tacho setting, then switch the wire to #37 slot and managed to get it work, with a setting on HIGH side. Vaughan diagram is applicable to this 95' 1.8L Miata, no B/W wire on #37. Thank you very much, koracing and Vaughn for sharing the useful diagrams and valuable pointers. I'll work on the CEL next and noted on the knock sensor pull up.

Hi, I have a same 1.8L 1995 miata, i have the same problem on the tacho, but jumper fitted, tacho still doesnt work. Did you pull up any wires to the tacho?

its a 1995. yes, jumper connected both pin but cant get it work. The car runs 2 cooling fans, so aux2 is occupied. Aux3 is the one to go... can I ask where to trace for the tacho wire? do I trace all the way to the dash connectors? By standard, there should be a wire connecting ecu to dash for tacho, am I right? I tried trigger the CEL(aux4) with disconnecting a sensor, and the ecu shows the CEL, but nothing on the dash. alright, will give a try

yes, i've bridged the two pins labelled 1800 MX5 right behind the ECU connectors. but tacho still doesnt work.

Hi, just installed a G4X plugin into MX5, NA8C, 1.8L managed to get the engine start up on based map, but have problem with the original tachometer not working. also, the CEL also does not turn on, despite setting is turned 'on'.