Mentat Ghola

Ok, YES I saw that article with detailed instructions on the OBDI B18c1 wiring. Very good stuff. Heres my dilemma. I dont have the B series harness. I only have the VX harness to work with along with a 4 wire O2 sensor. So Im going to be using the VX harness, while runing a P28 ECU.

Looking at my haynes manual, Im comparing the VX pinouts with the SOHC VTEC pinouts. Here are the discrepencies I have found


A11- nothing on the P28, EGR solenoid on the VX, no big deal, EGR will not be used
A17,A18- nothing on the VX computer, "lockup control solenoid valves" on the P28. Im assuming this is ABS related so no biggy.
B5- Condenser fan relay on VX, AC switch on P28, sounds like the same thing just worded diferently, no prob cause AC wont be used.
D3- my first problem. VX it goes to the 7 wire plug for the O2 sensor. Nothing there on the P28, so no modifications required.
D8-Another VX O2 wire, blank on the P28. No modification required.
D12-EGR related on VX, no problem
D14-the orange/blue VX wire, on P28 its white and goes to the O2 sensor as well. Ill just connect the white wire from the 4 wire O2 sensor to this pin by cutting th big VX Os plug and connecting the white wire to the orange/blue wire, right?
D16- VX O2 wire, nothing on the P28, just leave it there.
D17-PROBLEM!!!Map sensor wire. On P28 its it seems like its the signal voltage, on VX seems like its the ground wire (white) or maybe the power wire.
D21- DITTO!!! signal voltage for the VX while being the white wire for the P28. Looks like I can just switch the green/white wire with the white wire right at the map sensor.
Connection 125- PROBLEM!!! pin 6 is empty on the VX, for the P28 its the yellow/black wire coming from O2 sensor. I assume this is ground, can I just run that wire from the 4 wire O2 and hook it into the empty slot on the VX junction connection? Its the one on the driver side shock tower.
D22-different wire colors. Green white off the Os for the P28 (power im assuming since this wire travels in series/parallel with other potentiometers) No problem, just make sure the light green wire off the sensor ends up at this pin. right?

This seems to be the extent of the wiring discrepencies. So basically, I have to add the yellow black O2 wire to the junction at the driver side shock tower pin 6 (the only empty one on the VX, switch the map sensor input/signal voltage wires, and connect the white O2 sensor wire to the VX harness orange-blue, AND the light green O2 wire to the green/white VX harness wire?

If everything checks out, this could really help out the VX guys. Just 5 simple modifications. PLEASE SOMEONE VERIFY!!!!!!!!!!!!!

punkracer

ahhhhhhHA

i have a VX with a LS/vteC swap done just recently. i am using my VX harness and it works fine..sooo do it up

punkracer

oh and i am useing a chiped P28

punkracer

theres no need to change the o2 sensor...at lease on my car. my vx came with a four wire o2 istead of a 5 wire...so just plug and play

punkracer

Combustion Contraption

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by punkracer &raquo;</TD></TR><TR><TD CLASS="quote">theres no need to change the o2 sensor...at lease on my car. my vx came with a four wire o2 istead of a 5 wire...so just plug and play</TD></TR></TABLE>

this is total misinformation. ALL vx's came with a wideband o2 sensor, 5 wire, since the vx model is an economy model with vtec-e. PM poison for more info.

VTECVillain

I mapped out the wiring a few years ago for using a 4 wire O2 with a VX harness. I'm at work now, but I can post the info tonight when I get home. I know how overwhelming it can be when you look at the Helms VX O2 wiring and compare it to the other models but it's really not that hard to rewire. I'll post it here later tonight.

punkracer

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by LsVtec92Hatch &raquo;</TD></TR><TR><TD CLASS="quote">

this is total misinformation. ALL vx's came with a wideband o2 sensor, 5 wire, since the vx model is an economy model with vtec-e. PM poison for more info.</TD></TR></TABLE>

I did none of the such i one told him what my **** had done to it maybe its a 95 only thing

Mentat Ghola

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by VTECVillain &raquo;</TD></TR><TR><TD CLASS="quote">I mapped out the wiring a few years ago for using a 4 wire O2 with a VX harness. I'm at work now, but I can post the info tonight when I get home. I know how overwhelming it can be when you look at the Helms VX O2 wiring and compare it to the other models but it's really not that hard to rewire. I'll post it here later tonight. </TD></TR></TABLE>

ok cool!!! Take a look at mine too, maybe I got it right !

Mentat Ghola

oh, and can you verify the map sensor wires too? From my Haynes manual it appears that the input/output voltage wires have to be switched

1fastVX

You dont need to mess with the MAP sensor wiring. The only wiring that needs to modified is the O2 sensor. What I did was i swapped the plug from the O2 plug from the JDM harness I got onto my VX harness. All you do is remove the pins from the 5 wire plug and plug them into the 4 wire plug...though you do need to figure which one goes to the proper location. I just compared the Civic manual to my Del-Sol manual and figured the changes. My setup looks stock!

PS...what motor are you installing?

John

Mentat Ghola

LSVTEC. Can you do me a favor?My wiring manual shows D17 on the VX ECU to be the white wire going to map. On the P28 it says that D17 is the green blue, and D21 is the white. While on the VX ECU D21 is the green/blue. So according to my manual they are switched, and need to be switched back. This may be a mistake by Haynes, but could somebody please check in the Helms?

ri_rv

i also have a VX and this is what i did to convert from 5wire to 4wire... works perfectly fine.

http://www.hondaswap.com/forum...14242

no cel's at all.

Mentat Ghola

could someobody please check the MAP sensor wires....

93b18civic

i have an additional question on top of this. now the vx is a 5 wire right. now an ex is a 4 wire? i think? if i use a ex engine harness in a vx car what changes do i have to make at the shock towers to make it work?

Mentat Ghola

MAP SENSOR WIRING ANYONE?????????????