I HAVE A 1993 RX7 WITH AUTOMATIC TRANS.LOCATED IN CALIFORNIA.
IF I REMOVE MY STOCK 1993 ECU AND REPLACE IT WITH A 1994-1995 RX7 ECU / AUTOMATIC TRANS.WILL I HAVE ANY PROBLEMS?
THE# ON MY STOCK ECU IS N3A4
THE # ON THE 1994-1995 ECU IS N3A8
THEIR WAS A TECH SERVICE BULLETIN #12 IN 1992
THAT STATES A PROBLEM DURING WARM-UP/IDLE FLUCTUATION.
SOME RX7`S MAY EXPERENCE STALLING DURING DECELERATION ,THROTTLE RELEASED APPROCHING A STOP AND ALSO WITH THE AIR CONDITIONER ON.
THIS IS THE PROBLEM I HAVE.
ANY IDEAS???
THANKS.

 

HERES AN IDEA! TURN YOUR CAPS OFF!

now that we have that settled... i dont know the answer to your question,

 

Your problem has nothing to do with your ecu.

 

you will have a problem i beleive cause, 1993 was the only year for a few thing. 1993 had egr and i beleive the 94 they do not hope this helps

 

The parts fiche shows the following prefixes for the RX-7 ECU

'93
N3A1 - Fed MT
N3A2 - Fed AT
N3A3 (ends in 881A) - Cali MT
N3A4 (ends in 881A) - Cali AT

'94
N3C1 - Fed MT
N3C2 - Fed AT
N3A3 (ends in 881B) - Cali MT
N3A4 (ends in 881C) - Cali MT

'95
N3D8 - Fed MT
N3D9 - Fed AT
N3E1 - Cali MT
N3E2 - Cali AT

I don't think the ECU is the problem, but I'm curious about where you got the N3A8 ECU. I can't find it in the parts fiche anywhere.

Sonny

 

sorry about the caps.
i don`t have the n3a8 ecu yet ,its on e-bay.
phil

 

Anyone know if you can put a 93 ECU into a 94 (w/ EGR)?

 

i had a 94 ecu in my 93 n3c1a

 

I'm trying to go the other way, 93ECU -> 94 car

 

if the ecu is expecting to see an egr sensor signal than putting it on a car with no sensor will cause a CEL. going the other way will be fine.

 

My 94 has a EGR, so no problems. Just put the 93 ECU in and no CEL. Thanks!

 

Back in 1999 I received a letter from Mazda stating they would replace my ecu to fix this problem so I brought the letter and my car into a dealership and they replaced it for free. The funny thing is that I never requested it, they contacted me so apparently they did some sort of voluntary recall and it did fix the problem. You might want to call Mazda and give them your VIN and tell them you have this problem, they may replace it for free and then you could sell that '94 ecu.

 

the problem that fixes is the stalling/low idle with the ac on and the engine cold. if you have a different problem the ecu isnt gonna fix it

 

I've been told you can use a N3A2 Federal ECU in a Cali car. it won't look for the EGR sensor. I also have a 93 FD Cali car with auto trans and ECU # N3A4. let me know how this works out.
Jeff

 

hrmm i am having the same warm-up/idle fluctuation problem too. I just bought the car and i know the previous owner switched out the ecu. I know its not an aftermarket ECU but it looks like a Mazda stock and i'm not sure it is a 93 ECU. I'll be looking today hehe thanks.