Okay Ive assembled all the parts to do a dpfi to mpfi swap..However I have one question? Looking at my 90 si distributor plug shows 7 wires and my stock engine harness has 5 wires..(90 std) I see that you have to run two wires for CPS to the distributor how did you guys go about it? Did most people find a si dizzy plug and swap the wires out of the dx harness.. Any help will be really appreciated. Thanks!

 

anyone know?

 

assuming that you got an si harness as well....

the pins inside the plugs are the same, so what I did is pull the pins out of the std plug and insert them into the si plug then insert some pins w/ long wires into the extra spaces and run them to the ecu. now you can just plug the si dizzy in. this keeps the engine bay looking clean because there's no wire splices under the hood.
and it also makes it easier if you need to put a new dizzy in later, a new si dizzy will just plug right in.

 

yeah, you might run into a couple white wires that have no really distinctive qualities, just take a chance, and if it doesnt crank try switchin them around. I know this doesnt make sense, but once you get into you'll see what i'm tryin to say

 

I never got a si harness..What would a si harness run if I went to a junkyard.All I really need is a distributor plug.. Any clues?

 

You can use the DX plug and just repin them. Use a 2 pin connector for the other 2 wires.... Thats all I did and no problems at all. May not looks as clean but its barely noticable....

 

do you have both ends of the distributor plug? All I did was swap all the wires. The white wires are something you need to take a chance on. If it doesnt work the first time then swap them around. As far as the wiring goes. De-pin all the wires and match them to the other side of the harness. I hope you know what to do with the blue/yellow and blue/green wires. If you dnot have both ends you can still use the dx distributor plugs and swap them to the corresponding positions. The only wires that will be left is the blue/yellow and blue/green. You can just add wires to those and bring them to the ecu.

 

here is the pic using a dx distributor plug.