This is a harness that came with my dohc zc obd0 motor. Can you guys tell me if this is indeed for this motor? Will it plug right into my dx wiring?? It looks like some modifications may have been made, so that leads me to believe it's been converted from dpfi-mpfi, but that's really just a guess, I have no idea!!

 

It does appear to have been converted already BUT an even better question, is YOUR car already converted for MPFI if it's not already an Si?

 

No, my car is not yet converted, i'm just running a d15b7 with original dpfi. I want to be able to get my car back to stock form easily in the future, so I'm in the process of putting together a dpfi-mpfi conversion harness. I'm talking to the guys at Tyco currently, trying to get the right connectors.

If this engine harness is a converted dx, i'll be able to save my old dpfi harness for later.

 

You have there an si engine harness it wont work on your stock dx harness. If you need a conversion harness feel free to pm me as I make them.

 

i am going to attempt it on my own first. i'll try to take pictures of before and every step of the way. do you have any tips? where do you suggest routing the wires through the firewall at?

 

I completely unwrap my harnesses, and clean everything up, any wires that need replacing I will replace. The way I do my wiring, only 4 extra wires need to be run to the ECU, 2 for the dizzy and 2 for the injectors. Those get run like stock, and run right through the grommet that the rest of the harness goes through.

 

good way to do it. unwrap the sucker and check all the wires for possible opens, or cracking and fix them now before you install it. this will save you headaches later on down the line.

 

Yup, most of the wires on these harnesses are still good, main wires that begin to go bad is those that run under the dizzy like the o2 and reverse switch wiring.

 

listen to the man he speaks the truth!

 

If this is an si harness, then it must not be modified. Doesn't it kinda look like it's modified to you guys?

 

Yes and no. Difficult to tell from the pics you have posted. If it is modified then they did a calm good job of making it look like a stock si harness besides the red loom.

 

I have not messed with any si's before, so I don't know. Why won't this work on my dx car?

 

If this was actually on the dohc zc motor then I think it would only need to be modified at the distributor plug. I think the dohc zc has a cam position sensor outside the distributor, this is were it would have to be modified.

 

I have not taken the harness out to my dx to see if it will plug into the ecu side of the engine harness. Does it look like the correct one? I think the big round plug looks like the one that's on my dx right now. What are the other two right next to it?

In other words, what is different between a dx harness and an si harness connector? Why can't you just put an si harness in place of the dx harness when you're doing a dpfi-mpfi swap?

 

the difference in si and dx harnesses is the driver shock tower plug. dx have big plug and si has small plug hence the reason why they don't plug in.

also wiring is different.

 

yeah, i understand the wiring is different

so if I went to the junkyard and cut off the ecu side of the shock tower plug from an si, I could then use the shock tower plug on my dx harness and make a "conversion plug" that will allow an si engine harness to fit into a dx car, right? I should do that.

I understand that you must also rewire the ecu harness too and run extra wires into the engine compartment.

This is interesting stuff.