Could disconnected main harness connectors prevent engine from firing?

[xagna]

I am finishing up my KA singlecam to dualcam swap and am having hard time startin the car. I get both fuel and spark but the cranking doesn't lead into firing.

According to 240sx.org's FAQ on KA swap you need to swap the connection between main harness and engine harness; the connector that branches from the huge ECU connector. On the FSM diagram these two are labelled F1 and M53.

I didn't connect this connector because I have not sourced DOCH connector that I need replace with SOCH connector on that main harness and forgot about it ever since. Could this be the reason why engine is not firing although it is cranking well?
Modified by xagna at 9:33 PM 2/23/2007