okay... i dont really kno why my car is not running. i have a n374 ecu and a n370 harness that is on it. do i have to modify this harness(i think this is the problem)??? or is it better for me to go for the n370 ecu??? fyi: got a base model s5 and did a tII conversion to it with a bit of works.

whats the difference between the n370 vs n374 ecus???? i mean the only thing i can think that is different is the pinouts on each of the ecu. if anyone knows how to convert this harness to mate with, that can be even a greater help!

Pleazzzze help me!!!

 

They should swap over.
Getting ECU information out of Mazda is near impossible, so I doubt anyone can tell you the exact differences between the two models.
The pins should still be identical.


-Ted

 

i just did the exact same swap you did a month ago (91 GXL). I used the N374 ECU and my car ran really funky. It would boost, but the car would not speed up, it was very very slow (almost no power) and it sounded like the timing was off or one of the spark plugs was not firing. everything plugs right in but i'm not sure why exactly that the Jspec ECU was making my engine run like crap. luckily i had an N370 ECU (Aspec) i switched the ECU's and my car started up fine and runs like a charm. does anyone know why this would happen. B/C i still have my Jspec ECU and would like to try it again. this is my own experience, but i hope this helps you out

 

I don't know differences between N318 and N332 ECU.

I need help because i want install a N332 in my wiring harness N318.

 

I have seen the same problem on my turbo car a few years ago. and I did some rearch back then, and didn't find much. someone told me that has to do with the fule octane. N374 runs higher(not just 93) octane gas. and some setting are different in J-ecu. if you want it run right, tune it.

 

cannot be the octane levels, i run 93 octane with boosters (LA) and it just ran like crap. some guys on this forum are running JSPEC ECUs on their US harnesses w/o a problem. I'll try the JSPEC ECU on my US harness one more time, but I honestly just think that the problem lies in the ECU either its fried or just all kinds of f***** up. theres gotta be someone with more info on this

 

Posted by Kevin Landers a short time ago:
The n374 is an 89-91 turbo ecu. It's just the Japanese version of our n370, and is a direct plug and play for our 89-91 turbo cars. This will work properly in your conversion, if it is a working ecu. There is very little difference between them.

Any n37x part is 89-91 turbo. Any n35x part is 89-91 nonturbo. Any n3Ax part is a 93+.
__________________
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Kevin Landers
1993 RX-7 Touring
1989 Turbo Convertible SOLD

 

I swapped in a Jspec motor in my 90 FC and I got 3 N374 ECU that are in great shape and tested good, but when all 3 ecu's are plugged in, motor does not fire. When I plugg in the non-turbo N351 ECU, the motor starts. What's goin on?. please, someone help.

 

Found this old thread, but I'm running into the same problem JDM S5 TII conversion done on a 90 NA, using the JDM version N374 ECU and harness. Ran fine for some time, then blew the motor. Now after rebuilding the engine won't start anymore, not even with Apex PFC conversion... Anyone have luck on this?