i just got my motor today. my ecu and other sensor goodies where shipped in a different box i was sent a N340 ecu and s4 motor( or i ask for one) the ecu had one big plug with the wires cut off and the motor has two smaller plugs. is this the right ecu for this motor? also how can you tell an S4 from an S5.

 

thats a jdm s5 t2 ecu...probably won't work. s4's have metal thermostat necks, knock sensor on the center iron, single tps, twin scroll actuator, etc. etc.

 

Found this for you. Might help?

The below is US Spec

'84 - '85 GSL-SE ( N304 )
'86 - '87 All ( N326 or N327 )
'88 All, except convertible ( N327 )
'88 Convertible ( N338 )
'89 California ( N350 )
'89 Federal (non-California) ( N351 )
'89 California, Convertible ( N352 )
'89 Federal (non-California), Convertible ( N353 )
'87 Turbo ( N332 )
'88 Turbo ( N333 )
'88 Turbo, Japan/Euro ( N344 )
'89 Turbo ( N370 )
'89 Turbo, Japan/Euro ( N380 )

but then i have a list of ( these are 13B Turbo ones )

I think these are Jap Spec ones

86 - 87 ( N318 ) - Rev Limit 7500 - Made By Mazda
86 - 87 ( N318 ) - Rev Limit None - Made ByMazda
88 - 91 ( N340 ) - Rev Limit 7500 - Made By Mazda
88 - 91 ( N340 ) - No Rev Limit - Made By Mazda
88 - 91 ( N374 ) - No Rev Limit - Made By Knightsports

 

i thought it was a s4.5. or so i read some where. i got the ecu and other parts from Japan2la. i heard he was the go to guy. and where does the bov go. i see a nipple on the charge pipe before the intercooler. does it do there?

 

Info on Jspec ECU's:

https://www.rx7club.com/showthread.p...highlight=N374

 

From the large nipple shown in the jpg to the back of the TID.

 

That n340 ecu is a S4 jspec. Will not work with the aspec system. You need to fine an n318 or n332.
Thanks Robert

 

it is a jspec engine

 

yeah ive heard that too. i forget what the differences are though.

well its an 88 only, i know that