hatchsp

Ok guys. I have a 94 civic vx with the ever so great on gas d15z1. My coworker here has a 2000 si with a d16y8 in it and I'm wanting to swap the motor into the vx. The si is OBD2 and obviously the 94 vx is an obd1 car. What needs to be done to swap in the motor. I have an entire running car at my disposal to get parts from. I'm trying to gather some information as to what headaches we may encounter before starting. I haven't ever done a swap yet and appreciate any guidance to get this done. I've read that the wiring harness is different inside the car to the fuse panel or something and that's the biggest headache. Again I've never done this and any light shed on the issue would be greatly appreciated. Thanks again guys.

Relic1

mechanically the VX and every other OBD1 civic are identical as far as this swap. Electrically there are some differences.

the engine harness on the Y8 runs from the engine to the ECU with no connectors at the shock towers like the integras and OBD1 civics... so either pick up a Z6 engine harness or use the VX engine harness on the Y8 engine. It should line up pretty close (a few wires are going to be exceptions, I honestly do not remember which ones right now as I am going from memory)
The O2 sensor is going to be a bit of a pain, as the VX uses a 5 wire O2 and the P28 uses a 4-wire. Plus the O2 is in a totally different location. (VX up front near head, Y8 below intake near cat)
Either change the pinout of the VX harness or run separate wires for it. (the Z6 harness would be better here since the O2 is in the same location, move one wire and it will plug right into the VX chassis to ECU harness)

mounts will be a combo of the Y8 and Z1 mounts.

pick up a chipped P28 with the Y8 maps in it (preferably have it tuned)

also, there is a market for that engine/ECU/O2, look around and you can likely sell it.

hatchsp

Just so I grasp this for sure....

The y8 obd2 harness is no good because of the harness is direct to ecu and it's obd2 in an obd1 car.

The easiest way to wire it in will be plug in a z6 harness into the p28 ecu onto the y8 engine?

Tune the p28


This is the basics so far for a good swap.

Will my d15z1 dizzy work on the y8 to bolt up and plug into the z6 harness?

Relic1

the Z6 and Z1 distributors are the same, it will work.

if you go the Z6 engine harness route, you have to move one wire on the chassis side of your VX harness.
move the yellow highlighted wire from C129-6 to C102-2

hatchsp

Ok. Sounds like a decently simple swap. Should be a good improvement. Thanks a lot man. Any suggestions on what to do for a mild performance improvement? Was wondering if a cam would be worth it?

hatchsp

Another question regarding the ecu. I have a p06 I can get my hands on for cheap.

Would I be able to use the p06 and get it chipped for the y8 map on it instead of finding a p28? The vx I have has a p07 ecu in it already also. Could hondata work with that one instead maybe?

It would save money considering I have to get it chipped anyway.

mk378

A VX in good working order is money. You should keep it that way.

The P06 lacks the electronic parts to drive the VTEC system. You can add them to the empty holes in the circuit board and make it equivalent to a P28. The P07, like most VX parts, is majorly different due to its interface to the 5 wire O2 sensor.

Not sure why you are wanting to chip the ECU in a stock build.

hatchsp

I've heard to make the y8 run better like it should it's better to have it mapped.

I'm asking questions to do some research to make sure I do it right the first time and not half *** it.

By chip I mean map it to the engines characteristics (D16y8). This is what I've heard an read around the pages on the topic saying its better to do but if a stock p28 will do the trick then Ill do that.

But a stock vx is money eh? Was thinking to restore it to stock. Hard to find these in decent shape anymore. This one's not terrible either. Has some spots that need some love tho.

Relic1

adding the parts to a P06 to make it work with the VTEC engines is very easy if you can solder. (kits are everywhere if you know what to search for)

the P07/Z1 combo share very few parts with the rest of the honda family.
As a result they ae becoming rare and even sought after in some circles.
If the lack of power does not bother you, then add a vote to the idea of keeping it stock. the fuel savings will certainly make up for any investment.
Maybe a little suspension work (sway bars and some spring/shocks to pull it down a little) it's a seriously fun little car that sips fuel. (I drove mine like that for 3-4 years before the desire for more power crept in)

the Y8 maps are a decent amount different than the Z6.
Not life threatening, but if you are going that route, do it right, better in the long run.

hatchsp

Well... I've certainly screwed up selling my 2000 Sir....this one I'm going to hang on to. Your right. I'm going to keep it stock for now and save the money and get the little rust it has dealt with. It does drive amazingly well the way it is for what little it is compared to its bigger brothers lol. Thanks for the insight on it.

But I have one problem that is bugging the hell out of me.....I need the stock air intake. Do you guys know any places I could use to find it? I've searched but all I can find is the d15b7 or z6 and the throttle body is only 50mm....I don't think the d15b7 will fit it because I'm 90% sure it's bigger