I have a 92 civic si with the d16z6, I had purchased the aem ems series 1 as I have plans of turboing the car over the winter. I had installed the Ecu loaded a somewhat stock base map onto the Ecu but today at -24c go to start the car and the fuel pump would not pressure up the system... Switched out to the factory ecu again and it pressured up the system and started... Also brought out the laptop and plugged it into the ecu and with the key on it just kept saying ecu offline and would not connect... Any ideas ? Car/setup was running the day before....

 

Bad ECU would seem to be the obvious conclusion.

If you now reconnect the ECU, does the pump now prime and the engine start?

 

I am going to check it out in the morning... The cold wouldn't have anything to do with it would it ? As it ran fine the night before.

 

Can you post your map. running v1.19 I assume ?

 

Might have just been a poor connection at an ECU connector pin. Worth testing.