Originally Posted by Epstein
2500rpm is the magic MAFS number. This is the engine rpm limit when it can't find the MAFS. It runs really rich so that you don't blow it up, which is what is causing all the black smoke.
Now to the ECU. You can start off by listing the motor type (redtop, etc), the large number on the ECU cover, and who did your harness.
I have a Kouki S13 SR20DET Black Top, the ECU does not have a code in it because the sticker has been removed. I did the harness my self and had a guy look at it for accuracy and there were no flaws detected. I soldered all connections and shrink wraped everything. I will try the ECU code and see what happens.