HXMan

I got a question for you. Now, when you pull your stock motor the wiring harness pulls out with the engine. The part that pulls out connects directly to the ECU...at least that is what happens in my 97 Hx and this wrecked 99 Si I bought. Would I detach the wiring harness from the b16a2, and connect up the Hx harness to the b16 motor? That doesnt seem to make any sense.....it seems to me that I should just keep the b16 engine harness on the b16 engine, and not use my Hx harness. If almost all the plugs that go to the ECU pull out with the motor, there shouldn't be alot of wiring problems. I allways hear people saying they need to rewire for a knock sensor, or VTEC.....the knock sensor and VTEC wires on the Si pull out with the motor, so i shouldn't have to wire them up right?

For my swap, the Si motor pulls out with the B and C ECU connectors, connector A stays in the car. My Hx seems to pull out with all of the connectors, A, B, C, D.....I am hoping that, since the Si ECU only needs A, B, and C all I will have to do is rewire the green harness(think it is called the main engine harness?) in my hx to plug A, which I will cut out of the wrecked Si.

Judging from the helms manual, the wiring on the drivers side of the engine is the exact same, at least the wire colors are the same, and in the exact same position. Plus the plugs are the same.

There is soooo much going thru my head right now....I can't wait to get started on this. It is going to be a challange but I am going to learn tons!

One more thing....if I get a check engine light for evaporative emissions stuff....will that put my engine into "safe" mode with decreased performance?

Oh yea, thanks alot, I'm dying to know! Even if I don't get answers, I will find out myself. I just kinda want to know what to expect.




[Modified by HXMan, 5:39 AM 5/10/2001]

advanracing62

OK so you have a usdm si engine with the wiring harness and your stock engine with its wiring harness... All you would need to do is run the wiring harness through the firewall and to the new ecm and you'd basically be done. The only time you would want to use your stock harness is for JDM applications. The JDM harness is for right hard drive civics and such and will not work too well on the lefty's we have here in the states. It shouldn't require extra wiring just plug n play. I don't understand what you mean by plug A stays in the car, do you have an intermediate harness that runs all the internal electrics? I have that in my 92-95 and it's a bitch to rewire. Now one thing to remember is not all wires will be colored exactly from harness to harness. That is to say there may be 2 whole wires in the set that are not the same. I had to rewire my whole car cause my harness was JDM and such. I'm not sure how it is on the 98+ civics but i would imagine that it is the same. If you could clarify this A plug thing for me that would be a help.
As for the emission control ****... yes it is ****... and yes it will put you into safe mode if it pulls code.

HXMan

Damn, the evaporative emissions stuff on the 99+ civics is completly different then the 96-98's. Man, I may have to fool the ECU somehow until I can pull the phuckin gas tanks! That is the only way I will be able to avoid code 91.....the gas tanks will have to be swapped out. I will get back to ya on the plug A stuff.

HXMan

Ok, this is the part of the harness that goes to the ECU that pulls out of the Si with the engine....In the helms manual these plugs would be called B and C, I am not sure what the green connector is called. I think it is called the main engine harness. http://albums.photopoint.com/j/View?...535&p=48247555

This is the part of the harness that does not apear to pull out with the b16a2. The ECU connector that is shown there is connector A. http://albums.photopoint.com/j/View?...535&p=48247557

And this is the connector on the drivers side of the engine compartment that links the wires that go through the firewall to the engine. http://albums.photopoint.com/j/View?...535&p=48247554


[Modified by HXMan, 10:16 AM 5/11/2001]

HXMan

Ok, I got a plan.

I am going to connect my Hx harness to the Si engine....this way I will only have to add wires for a few sensors, and move a bunch of pin locations at the ECU.......

Yellow Dragon

You're going to have to run the wiring for VTEC, knock sensor (HX is non-VTEC right?).

Also, the evap wires will not affect performance/throw the ECU into safemode I DON'T THINK. You do have OBD2 and maybe someone else can give you a better answer. I didn't hook up mine, but mine is OBD1. Not sure if that makes a difference.


[Modified by Yellow Dragon, 10:57 AM 5/11/2001]

HX_Guy

One problem HXMan...

First off..the SI ecu will not plug into your HX harness (the ECU plugs changed in '99)

If you use the HX harness, your gonna have to use a 96-98 DOHC VTEC ECU (GSR?) and will have to run wires for the knock sensor and rewire the primary 02 sensor (HX has VTEC-E so you dont need to run VTEC wires)

HXMan

No way? The plugs did change pin locations alot, they are completely different in that respect, but I think the plugs themselves are the same....I am going to find out right now.

HXMan

Hmmm.....plug C from my Hx just plugged into the plug C location on the Si ecu.....so one works.