JDM P73 ecu problem

Alright here's the deal. I bought a JDM type-r ecu off ebay a while back and from what i can tell its all legit. But the problem is everytime i turn off my car the ECU resets. I could have it running in my driveway, pull any of the plugs in the engine that would throw a CEL, the CEL would show up on the dash, but when i turn the engine off and turn the key back to the "on" position the CEL is gone. Has anyone ever heard of this before? It seems like I have to go through the whole re-setting process just to have the car run right. Plus I'm only getting vtec once in a while :( Is it just a bad ecu?

a check engine light will only show up if there is a current problem, if u shut the car off and plug whatever u unpluged back in then turn your car on, there should be no CEL. however that code will be stored in your ecu. the only way to see if its resetting itself is to cause a CEL, fix it then pull the stored codes and see if its still there or not. As far as your Vtec problem... vtec only engages if your coolant is past a certain temp (Vtec wont engage with the engine cold) and your oil pressure needs to be past a certain psi (if your low on oil it wont engage)

well here's the thing, i wouldn't plug it back in. just turn it to the on position, take out my scanner and it would show an "Err" on the screen. The ecu just won't hold any codes. Just a couple weeks ago i would be driving then it would turn on. Go home and try to pull the code and NOTHING would show. I had to find my old P72 to drive with just to find the code. Turns out i had a bad O2 sensor and fried Engine Temp Sensor. after replacing those the car ran without throwing codes while driving with the JDM ecu. So it was something big that the ecu wasn't finding or storing it. Could there be something in the ecu that fried and won't store anything anymore? or is this just normal with jdm computers?

thats weird.. never heard of that. Usually if an ECU fries it wont work at all.... im not too familiar with JDM ECU's... if it does it again jump the service connector and try to pull the code that way.... mayber your scanner doesnt recognize a JDM's signal?? i dont know what else it could be....