92 S13 ECU compatibility?

[JimLecesse]

I picked up a 1992 S13 coupe, AT. The car was running rough, I took it to my shop and they found out that injector #4 wasn't grounded, and told me that I need a new ECU. I just took out the ECU, and it has "93 240SX" painted on it (salvage yard part?)

1. is the fact that it is a 93 ECU the reason why the scan tool picked up a code?

2. what other ECUs are compatible w/ a 92 S13 coupe, auto transmission?

there is also a sticker on the ECU that says " 29 A11-B45-G71 3603"

any help would be great, thanks

[masticatingcow]

1. No, the shop probably used the same CONSULT interface to pull the code(s) off the 93 ECU as they would have if it had the 92 ECU. So, it would have picked up a code either way. Also, the ECU does not throw a "I-do-not-belong-here" code, and doesn't care as much about serial and VIN numbers as people do.

2. Any 91-93 auto ECUs should drop right in. I'm not too sure about the 94 S13 ECU, though I'm pretty sure all the 94 models were just leftover 93 'verts that didn't sell. If that's the case, a "1994 S13 ECU" is actually a 93, which would work.

In any event, I am inclined to doubt that the #4 injector and mismatched ECU are in any way related. An S13 ECU is an S13 ECU, no matter what. It wasn't until 94-95 that OBD-I was introduced on the S chassis cars, and so post-1994 (e.g. S14) ECUs will be drastically different.

My guess is that the #4 injector failed on its own, and in the process of diagnosing the problem, the shop may have found some critical, perhaps unrelated, error in the ECU.