so someone hacked up a perfectly good EF si engine harness on this car Im working on. My question now is can I use the engine harness from a DA to get things back on track? I know with EGs and DCs the engine harnesses are interchangeable I just wasnt sure about the older stuff.
Thanks in advance for the help

 

Short answer = NO.

 

Long answer = YES
It's not interchangeable, like you pointed out with the EG and DC.
However, if you have a bunch of time and electrical know-how then you can get the chassis side harness plugs from a DA, figure out what all the wires are and where they belong, and then swap our chassis plugs. Serious nightmare work for most people. There are no write-ups on this so you are all on your own.
Far easier to just get a new Si harness.

 

thanks guys

 

It needs to be from a si and not a dx or anything and from what I remember the 90-91 is different than the 88-89, their is an extra sensor on the back of the block. Correct me if I am wrong.

 

88 is different than 89-91. the sensor is the cold start valve (or something like that). its not worth your time to try and make the DA harness work. just get yourself a stock replacement that matches the cars wiring harness. if you need one feel free to pm me. i can make you a brand new harness (my sig below has pics of my work).