D15, D16, D17 and Mini-Me swaps
By dylan0123
#350775 Sorry to do this, but I need help fast. I need a straight-up, no bull-crap answer so I can get this done this weekend and get back on the road.

I need to swap my friend's D15Z1 from his '92 Civic VX hatch into my '93 Civic CX hatch. I will be using his 5 wire O2 sensor and P07 ECU. The motor ran perfect when we pulled it out of his car.

The Main Question:
How do I make this motor work in my CX? I'm only worried about the wiring and electrical aspect, not the actual mechanical swap itself as I'm sure it won't be difficult at all. I want it to run like it's perfectly stock. No check engine lights and no sputtering. The motor is in perfect condition and was running great when he pulled it from his VX.

How do I wire up the vtec and the o2 sensor? Where do I need to run all the wires to and from?

I need wire colors and pin numbers and diagrams and all that stuff.

edit: Am I going to have to do all the wiring like the guy in this link?: http://ecomodder.com/forum/showthread.p ... 23433.html

I really hope not cause I don't know where to begin with that
Last edited by dylan0123 on Fri Jan 09, 2015 12:37 am, edited 1 time in total.
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By teal_dx
#350789
dylan0123 wrote:edit: Am I going to have to do all the wiring like the guy in this link?: http://ecomodder.com/forum/showthread.p ... 23433.html

I really hope not cause I don't know where to begin


Unfortunately, you'll be doing the same wiring that the guy in the link did and then a little more. His LX had a D15b7 motor which had a 4-wire o2 sensor. Your CX has a D15b8 which uses a 1-wire o2 sensor. So you will have the wiring for the 5-wire o2 sensor as well as everything else he did.

Just to give you an idea, here's the p07 pinout:
http://repairguide.autozone.com/znetrgs ... 061b2b.gif

and a general OBD1 pinout for all civic ecu's (you can see the slots that are empty except for VX applications) You'll have to pin & run all those wires. I looked at the link you posted, I didn't realize it was that much work to properly swap a D15z1. I didn't know that the vx had a 4th main harness plug on the passenger shock tower. So before we go all out and dig up all this info, are you sure you still want to do this swap? You couldn't have picked a more complicated OBD1 swap :lol: But not saying it can't be done :thumb:
Last edited by teal_dx on Tue Jan 06, 2015 8:15 pm, edited 1 time in total.
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By suspendedHatch
#350796 Swap the engine harness over and run the pins to the strut tower harness.

Why is wiring so frightening to people? I converted a CRX to OBD2 and swapped in a D16Y5 last winter. Wired the CRX dash and main relay to the OBD2 one-piece harness. Wasn't bad at all, considering I had very little reliable info to go on.
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By teal_dx
#350804 I can see it being intimidating if he hasn't done anything like that before. You just gotta dive in, know your plan and take it 1 wire at a time, using proper soldering & connections. If you're not 100% sure, order a pizza & beer and get someone over who can help you out. Once you learn this stuff, it will come in handy all the time. :thumb:
By dylan0123
#350833 The problem is that i need to do this in one weekend.

suspendedHatch what do you mean swap the engine harness over? You mean swap it out of the old vx chassis into my cx chassis? How difficult/time consuming is that?


On those pinout diagrams is that viewed as your looking into the ecu with everything unplugged and the ecu is sitting in your hand, or is that like when youre looking into the connections that plug into the ecu?

How do i get rid of everything related to emissions? In llinois we dont have to get our cars inspected and i just want more simplicity.

On my dsm i made a blockoff plate where the egr valve bolts up, ripped out the charcoal canister and purge control valve, and blocked off some vacuum ports on the throttle body. Is there a way i can do all that with my CX civic so it eliminates some wiring that i'd have to do for this swap? Will the car run right without all that stuff?
Last edited by dylan0123 on Fri Jan 09, 2015 12:39 am, edited 1 time in total.
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By suspendedHatch
#350834 I leave the harness on the engine when I do a swap. Piece of cake. Shouldn't be any soldering if you swap the harness over. Go to the junkyard and pull some ECU to strut tower pins. They don't have to be the right color wires.

Honda emissions devices are incredibly simple and the VX wont run right without EGR. EGR and charcoal canister, that's it. Minimal vacuum hoses. If you are going to rip that stuff out for no reason, good luck getting it to run right. I have better things to do than to help you.

Make sure you get the EGR control box off the firewall and the wideband O2 sensor from the exhaust manifold.

If you're not getting the D15Z1 for fuel economy, I suggest trading it to someone on fuelly.com for a D15B7 and getting some cash on top of it.
By dylan0123
#350835 So im not going to be able to just unplug my ecu and put the connections into that p07 ecu? Am i going to have to hack off my plugs and rewire the wires to his VX plugs? If so, maybe im just better off getting my p.o.s. d15b8 motor rebuilt.

Anyone know a good shop to buy rebuilt d-series shortblocks and heads from? Im always looking on ebay but people are always asking $700 for a used 200k+ mile motor pulled from a junkyard
By dylan0123
#350836 Im doing this swap because its my only option. I need the civic running by next monday cause its sitting in my friends yard taking up space and he doesnt want it there (i dont blame him, at all).

Doesnt the harness all run through the firewall and under the dash? And all up the steering column and to all the interior lights and crap? Its a huge mess and i dont have the experience or information to deal with all that right now
Last edited by dylan0123 on Fri Jan 09, 2015 12:35 am, edited 1 time in total.
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By teal_dx
#350850 The whole purpose of the D15z1 is the fuel economy while offering decent power in the usable rpm range (115 HP). What exactly is wrong with your D15b8? If your bottom end is knocking and you don't want to deal with any wiring, egr, etc... You could just put your D15b8 head/intake on the D15z1 block.
You'll still be stuck with the restrictive 8-valve D15b8 head with 70 HP, but everything will be strictly mechanical, no wiring involved.

edit: pretty sure nobody has ever done this swap because it's putting the worst head on a decent bottom end, so I'm not sure which head bolts you would use. Also put the oil control jet from your cx block onto your zx block, non-vtec heads need it.
Here's a pic of one removed from a D15b7 block when I was about to bolt on a vtec head:
Image
The thing I'm not sure of is if the timing would be off 1/2 a tooth.
Some head swaps (such as putting a d16z6 head on a D15b7 or D15b8 block- yes some d15b8's came with 4-valve relief cut pistons- results in timing being 1/2 tooth off) Easily corrected by an adjustable timing gear.
By dylan0123
#350864 Zero compression in cylinder 2 and 3 on my D15B8. Thought it was a headgasket so we pulled the head, noticed a chunk missing from a valve.



Can someone please post a step by step guide on how to swap a VX motor into a CX chassis? I cant find one anywhere. Surely someone has made one
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By teal_dx
#350888 Alright, here's the best I can do w/o knowing any wire colors or having the cars in front of me to look at. (I've even seen diagrams in manuals have a wrong color wire listed before, so don't trust wire colors 100%)
I'm assuming both cars are manual.

You need wiring for the 5 wire oxygen sensor, EGR valve and VTEC. I'll do this 1 post at a time since I'm at work.
I'm going to refer to this chart: http://technet.ff-squad.com/wiring.obd1.htm

Vtec first since it's the easiest. There's 2 wires and a ground.

Image
Vtec solenoid - run this wire to pin A4 on connector A

Image
Oil pressure sensor - run this wire to D6 on connector D
The other black wire goes to a chassis ground. (There's a nearby one on top of the thermostat housing)


If you want to do it the OEM way by using the D15z1 harness & pinning into the shock tower harnesses or just run all your new wires in a loom going into the cabin, that's up to you.
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By teal_dx
#350892 VX 5-wire o2 sensor

I messed with converting a 4 to 5-wire years ago on my old civic HX, so I'm a little rusty here... I'll probably edit this post a couple times based what I can find online.

Your cx uses a 1-wire o2 sensor and the VX ecu uses a 5-wire (expensive) wideband o2.

Looking at the OBD1 pinout diagram, I see:
A6 - Heater Control
D3 - LAF Sensor: Label (?) wire color: red/blue (may be wrong)
D8 - LAF Sensor: VS+ wire color: ?
D14- LAF Sensor: IP+ wire color: white OR white/red
(this is currently the primary heated signal for your 1-wire o2)
D16 - LAF Sensor: IP-, VS- wire color: blue/green

I've used this chart before but never paid attention to the VX stuff... I can't verify that any of this is 100% correct without seeing what you actually have.
Those wire colors are best guesses. They refer to the wire coming from the connector that plugs into the ECU.

Now for the wires coming from the o2 sensor.
OEM vx o2 sensor is on the right side of this pic:
http://img.photobucket.com/albums/v675/ ... MG0193.jpg
another angle: http://img.photobucket.com/albums/v675/ ... Medium.jpg

White goes to D14
Black goes to D16
Red goes to D8
Orange to A6
Yellow goes to thermostat ground

If my memory serves me correct, there are 7 wires going to the 5 wire o2 sensor where it plugs to the engine harness. 2 of the wires combine into a resistor built into the plug (the square part in the pic). This is where it gets cloudy and I can't help you without actually seeing the wires on the VX you have.

Your best sure bet is to follow these wires yourself on the VX, from the sensor to the ecu, before you do any removing/cutting.


edit, found this if you need a second reference: http://img440.imageshack.us/img440/1024 ... arness.jpg
Last edited by teal_dx on Fri Jan 09, 2015 6:40 pm, edited 1 time in total.
By dylan0123
#350912 Awesome, thank you so much man! Now we're getting somewhere :)

So what do you think is the best way to tie into the wires going to the ecu? Just clip those gator-clip things onto the wires, or is it best to solder the joints?

Also, I guess i dont understand this: When I run wires from the 5-wire o2 sensor and tie them into the correct pins on the ecu, where are those other wires coming from and going to? it's like, why are they even there already? i mean its not like this cx car came with that 5wire o2 sensor from the factory, so i just dont understand why theres even wires to tie into.


I might be able to get some pics and post them up on here tomorrow night, so maybe keep an eye out for that.

teal_dx I can't thank you enough for all this help
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By teal_dx
#350926 If there are wires already on the plug, maybe they aren't going to anything. They moght stop at the shock tower plug if there's a blank on the connector on the other side. If there aren't wires, you'll have to de-pin a wire from somewhere else (like an old scrap harness), cut/solder and click them into the connector. Or buy new empty pins.

I show an example of this about 3/4 down this page: http://civic-eg.com/viewtopic.php?t=92

That's a shock tower plug, not an ecu plug, but same concept.

Whatever you do, please don't use these:
http://i01.i.aliimg.com/wsphoto/v0/6039 ... nector.jpg

Always solder & use the OEM pin into the plug whenever possible.


I'll look into the EGR wiring sometime today :thumb:
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By teal_dx
#350931 I've never messed with a VX engine or worked on a VX civic,
So Here's what I know, which is not everything:

First looking at the pinout,
D12 is the EGR lift sensor
A11 is the EGR Solenoud Valve
Run said wires to A11-Solinoid control(orange/blue) and D12-EGR lift sensor input(white/black). ground is also needed to the thermostat housing.

In addition to the VX intake with the EGR valve, you need to install the EGR Control Box from the firewall of the VX.