OK, here'e the pieces of the puzzle, maybe someone has run into this and can help me out.
'88 civic hb dx
ef hb si engine harness
1st gen b16a (cable trans)
everything is all good except the plugs on the left (driver's) side shock tower.

The dx harness is 1 large round plug

The si harness is 2 small square plugs

I know the green one is the injector resistor box. What to do with the other square one, though? Re- pin it into the round one? That was my plan, but the etm I have is not making sense (yes, I've used them before). The pin colors and locations are not matching up w/ the plugs!!!
I guess the main ? here is has anyone done the dpfi-mpfi conversion using a factory si harness, and what wiring changes did you have to make considering it's not plug-n-play
TIA to anyone w/ insight!!!


Modified by Galvatron at 9:09 AM 9/4/2003


Modified by Galvatron at 9:09 AM 9/4/2003


Modified by Galvatron at 9:10 AM 9/4/2003

 

the right way to do it...
u otta use ur stock harness and borrow cables and plugs from the Si harness....

theres no actual way of u repinin the whole harness and get it all right at the first time

beleive me.. i have been there.... not good... just use ur stock one and modify it

 

i agree with what USDM 4G VTEC said.

fyi:
i just looked into the same thing for my friend. he has a 90 dx and its getting a 91 si motor/trans/wiring, etc. after looking over the pin outs and wiring diagrams, we are going to use the DX engine harness on the Si motor. we'll just add any Si plugs that we need to the DX harness (like the 2 more injectors, injector resistor box, etc).

 

Thanks guys, that's what I was afraid you were going to say. After I made the whole si harness all pretty and stuff
I think I might still check it out a little more. It isn't much more than re-pinning that plug, then changing the pin-out on the ecu plugs, right??
I have plenty of confidence in my wiring skills, it's the etm I'm using that has me worried.
Can anyone w/ an etm double check this:
big round dx plug = c313
green rectangular si plug = c174
white rectangular si plug = c175???(I can't even find this plug in the etm except in the 'connector and wire harness routing' section in the back, it doesn't show up in the schematic at all!!!)
I was also thinking the mystery plug could be c314, but that's a round plug WTF!
Any help is MUCH appreciated.
Am I crazy for even thinking this is possible?

 

This is a write -up from a guy called cui on the CRX Resource:
{Not sure if it is accurate but it might help you...}
Re: MPFI Swap (Score: 1)
by cui on Monday, October 21 @ 00:58:31 CDT
(User Info | Send a Message)
I spent the whole day trying to figure out how to make the Si harness to work...and I almost gave up...but I was too stubborn to say no


Here's what need to get the Si harness to work...in fact, I think it is much better than modifying the DX...(that is, once you figured out which wire goes to which...)

1) Parts you need:

1a) you need to add 4 wires totoal thru the firewall. (try to get them the same color, it will make your life much easier.)

* 1 wire for Cylinder Position Sensor 1, ECU pin# C1, Blue/Green, 4 ft
* 1 wire for Cylinder Position Sensor 2, ECU pin# C2, Blue/White, 4ft
* 1 wire for Injector #2, Red, ECU pin# A3, 6 ft
* 1 wire for Injector #4, Yellow, ECU pin# A7, 6ft

1b) * you will also need a DX 14 pin female connector for the right hand connector, C175...as the DX has 14 pin, but the Si harness only has 8 pin.

1c) * you also need to source a 6 pin square male connector, C212. This connector is missing from the DX.

1d) * couple pins for ECU...source for junk yard.

2. Wire connection
2a) on the round connector right next to the main fuse panel, C210, find the TW sensor wire, the Red/White wire, and cut.
Solder the connector end wire to the extended Blue/Green wire...you just connected the Cylinder position 1 wire.

2b) the remaining loose end of Red/White wire,
connect to the Red/White wire of C212, the 6 pin connector right next to the C210. This the Si TW sensor wire.

2c) find the Red/Yellow wire on C210, the the TA sensor, cut. (same as in procedure 2a)
Connect the connector end wire to the extended Blue/White wire, this is for the Cylinder sensor C2.

2d) connected the loose end of Red/Yellow to the 6 pin C212 Red/Yellow wire. This is the Si TA sensor.


Now...here's the hard part...
2e) on the left hand side, remove the all the wires on the 8-pin connector of C175...plug them in the the 14 pin DX female connector describe in 1b...

here's the order:
Si C175:
pin1, Red, #2 Injector
pin2, Brown, #1 Injector
pin3, Lt Blue, #3 Injector
pin4, Yellow, #4 Injector
pin5, Black/Yellow
pin6, Blue
pin7, Blue/Yellow
pin8, Yellow/black...resistor box

Plug Si pin#2, Brown, to the DX pin #5, Yellow, this is for Injector #1.

Plug Si Pin#3, Lt Blue, to DX pin# 3, Red. Injector #3.

Plug Si Pin# 5, 6, 7 to respective DX colored pin.

Plug Si Pin# 8, Yellow/Black to DX pin #1, Yellow/Black...this is for the Main Relay.

Connect Si pin#1, Red, to the extended wire Red, for #2 injector

Connect Si pin#4, Yellow, to th extended wire yellow, for #4 injector.

Now, there is 4 more wires need to be routed from C175 to C212. They are color-matched.

they are Yellow/Green, Green/Balck, White, Yellow.


3) swap pins at ECU (move two wires, and add two wires)

3a) move C1, Orange, to B10, for the new Si Crank Angle pin location
3b) move C2, White, to B12
3c) add the extended Blue/White wire to C1, for Cylinder Sensor 1.
3d) add the exnteded Blue/Greeen wire to C2, for Cylinder Sensor 2.

That's it! It only took me 8 hours to figure out which wire goes to which I hope this is easier for people choose to use the Si harness in the future...

 

88dxcrx- THANK YOU SO MUCH
That is exactly what I was looking for!
I owe you one.

This is why I Honda-tech. Ask a question, get an answer. So simple.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Galvatron &raquo;</TD></TR><TR><TD CLASS="quote">88dxcrx- THANK YOU SO MUCH
That is exactly what I was looking for!
I owe you one.
This is why I Honda-tech. Ask a question, get an answer. So simple.</TD></TR></TABLE>
Cool Man,Good Luck...

 

all i have to say is have fun man

i would prefer modifying stock dx harness any day over doing dx---&gt; si harness

 

Did it work right on the 1st try or did you have to mess with it a little?
Are you still using that harness now?
Good info and write up.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by USDM 4G VTEC &raquo;</TD></TR><TR><TD CLASS="quote">the right way to do it...
u otta use ur stock harness and borrow cables and plugs from the Si harness....

theres no actual way of u repinin the whole harness and get it all right at the first time

beleive me.. i have been there.... not good... just use ur stock one and modify it</TD></TR></TABLE>


Yup

BTW http://www.truent.net has a awesome dpfi-mpfi writeup.....wev'e used it.