Everything is in place... Or this is what I have so far, please tell me if something is wrong.
1990 Dx hatch. I have already the LS tranny and motor sitting in it,
Also the 1990 Da (Acura integra) Ecu plunged in... I'm in search of the si harness witch I think is the only thing I'm missing to fire this motor up. Please tell me if this would work out!?????
I still have the sohc harness... But I'm thinking with the Si harness this should work out I hope.

 

the SI engine harness will not work with the DX chassis harness - you need to use the DX engine harness and convert it from DPFI to MPFI

 

Do I keep it obd 0 or do I have to convert anything to obd 1?
Do I still use the 90 Dx Ecu or the 90 Acura Da Ecu?
And thank you so much for your help and info.
Working on an Ef is type complicated. ��

 

Your stock DX harness needs to be used with the LS engine. This is a general rule with swaps, the wiring stays with the chassis and is modified to run the engine properly.

The main problem you currently have is that your DX harness is only wired for 2 injectors, but needs to be modified to use 4. Do some research, there are plenty of good threads that show how to do this.

Use the ECU that suits the engine. Keep it OBD0 because you're running a stock motor. The benefits of OBD1 are only important if you're tuning.

 

Yes, back in 1999 it was. Today, there are countless threads on this forum about the very same swap you are doing. 10 minutes worth of searching will give you all the answers you are looking for.