# How to know which E.C.C.S (ECU) should be installed



## BruceB (May 16, 2016)

Hello,
First let me thank you guys for having this forum. It may help a lot.
Second I want to thank ZBum for helping me decode the VIN.
The gist of it:
I just picked up an 84 300zx (JN1HZ14SXEX021286) and I'm thinking the motor has been replaced. There are a lot of wires and vacuum lines disconnected but once warmed up it runs strong and the suspension is tight.
BUT it is running really rich. Lots of brown smoke and the O2 sensor is not getting power. 
Only codes I get on the ECCS are 23 and 31. 
There is nothing written on the ECCS at all. I see there are a lot of different ones that will fit that model too but what if the motor is out of an 87 or something, ARGH. 
I have replaced the O2 sensor, so I know that is good and it's getting battery voltage on pin 115 of the ECCS. 
If anyone could help with which ECCS should be in there and maybe how to identify the motor that would be a wonderful thing.

Thanks a bunch in advance,
Bruce B.


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## BruceB (May 16, 2016)

Where did all the replies go?


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