I RECENTLY DID AN MPFI SWAP IN A 88 DX HATCH BACK USING AN S I WIRING HARNESS AN INJECTORS BUT WHEN I TRY TO START THE CAR ALL IT DOES IS CRANK AND GETS NO SPARK I WANT TO KNOW IF I SHOULD USE A DX WIRING HARNESS FOR THIS

 

Yes you should have used the DX harness and added the wires that you needed. Turn off the caps lock too.

 

yup use the dx harness, always start with stock and modify from there. took me like 3 hours to convert to mpfi from my dx, but if i were to do it now, would probably take me 30 mintues

 

can i use the injector rail from the s i or do i just use the resistor box

 

You'll need to use both plus the Si injectors.

 

use the complete si intake manifold which includes the fuel rail and injectors along with the si dist and resistor box.

im assuming you have a spare si harness, well modify and get the wires you need from the spare si harenss. good thing aobut start with an si harness is that you got the resistor box already hooked up with the wires, so the only thing you gotta do is put the 2 dx injector plugs into the mpfi injector plugs, then run 2 wires that go to the mpfi injector plugs, then run 2 wires to the dist. then make the neccesary changes to the ecu plugs. very simple

 

YEA I HAVE A COMPLETE S I HARNESS COMPLETE BUT WHAT I DID WAS I FOLLOWED THE HOW TO GUIDE I RAN THE WIRES AND ALL THAT BUT INSTEAD OF THE DX HARNESS I USED THE S I HARNESS WICH I THOUGHT WOULD BE BETTER BUT IM A JERK AND THATS WHAT I GET I WANNA THANK ALL OF YOU FOR YOUR HELP AND IF YOU HAVE ANY MORE INFO THAT WOULD BE GREAT