nextgen

Alright i have a 2000 civic hx with the stock d16y5. Motor is making some noise and has 230,000 miles so its time for a replacement. Im wanting to just do a y8 swap but im trying to get everything needed before we tear into it.

The hx is vtec but it is vtec-e and it has has a few different things then the ex and the other models have. Hx has a egr system and ive heard it has a 5 sire 02 sensor rather then the normal 4 wire.

So my question is will i be able to use my stock hx wiring harness or will i need to get a harness from a 99-00 ex?

Ive tryed to search this and ive read like 6 different things. Im looking for some legit answers here.

I know with the motor i will need a 99-00 ex computer, just trying to see if i need the harness aswell.

Thanks in advance.

Arthas

Do the Hx's have a 2 or 3 wire IACV?

nextgen

to tell you the truth im not really sure. What would this cause?

nextgen

i cant believe im not able to find any info on this. Its like noone has put a y8 in a hx before? I figured it would be a super common swap

94EG8

Keep the HX harness, you'll need a '96 - '98 EX ECU ('99 - '00 HXs are OBD2A unlike all other '99 - '00 Civics)

Both, automatics are a 3 wire, 5 speed is 2.

nextgen

weird, thanks for the information. I greatly appreciate it.

So does it matter if the y8 i get is from a 96-98 or 99-00? I can get either one here in town. Is one easier then the other to use if i use my stock harness and 98 ex ecu?

Thanks again

94EG8

'96 - '98 is a little easier, mostly due to the distributor plug and the '99 - '00 Y8s having air injection.

nickcrank

i today bought a 98 y8 engine to go in my 96 hx. i didnt get a y8 dizzy though. will my dizzy work and would i have to switch the ecu out?

nickcrank

if anyone is reading and interested with my swap, i bought a exedy stage 1 clutch kit with 11lb flywheel to go with the y8 swap.

this coming friday i will be starting the y5 to y8 swap using y5 dizzy, harness, intake, and tranny. hopefully it fires and vtec at least engages no matter the rpm but if it doesnt engage i will be ok with it. if nothing works, the y5 is going back in and im going back to the drawing board....

fleabag

Doing a y8 swap into a 96 hx is not going to be easy. Even if you swapped ECUs, you're going to have the wrong o2 sensors on there and the length will be all wrong. The easiest and cheapest thing you can do if you're doing a Y8 swap is to keep your Y5 everything but the block and the valve head. Essentially you'll just use the Y8 for its head and block and not use anything else. If you try to use the Y8 manifold and distributor and other things, you'll be in for a major headache since they're different on the Y5. So sick of these people chopping up these HXs when they're already a rare breed of vehicle as it is. They'd be doing a world a service if they would focus their efforts to chopping up Civic DXs and LXs and putting Y8s in there instead of the rare Civic HX with its Y5 engine.

nickcrank

well the only thing im using from the y8 is the block and head, the one thing that might not work is vtec, if it doesnt, the engine will still run. about sensors and stuff, its ok bc i have an open ehaust and a short ram intake.

also the only reason im doing this is bc the y5 is done and needs a short time replacement while im building it and thats where the y8 comes in at.

fleabag

If you're just using the block and head, then this setup will work just fine. Vtec will work since it's the same plugs and layout.

gwl

I had a 97 HX with 300k miles. I went ahead and had it rebuilt instead of getting an used engine. I want it keep it original plus I didn't want to hassle with the Smog police here in California. At the end, it didn't matter because I sold the car.

nickcrank

if vtec does work im just wondering what rpm it engages... either way i will find out this weekend

Project Dad

what did the rebuild cost you? gonna do the same

fleabag

it will engage at the same point as it always did, however when it engages, I'd imagine it'd feel a bit weird considering that it's engaging so early.. Again, if you change only the block and head, it should work exactly as it normally would though the power band will be all screwy with no low end power and then I'd imagine a power lull from 2500-4500rpm since it's engaging a cam and lift profile that is inappropriate for the power range.. I may notice this kind of stuff but you may not notice this kind of thing.. Anyway you're doing an engine rebuild and this is just to get you by anyway right?

civek97

First off, let people do what they want to do. What do you care? It's not your car.

Second, the Y8 and Y5 use the same block, but with different casting numbers. Therefore, it wouldn't make much sense to swap the block. The differences for the Y8 and Y5 are as follows:

egr intake manifold (the y8 auto and manual are also different)
intake manifold gasket (y8 port flange is bigger than the y5 so it causes an air leak when using the y5 gasket)
rocker arm assembly (y8 has lost motions y5 has roller rockers) ***will post pics when battery is charged***
cam (y8 is vtec 3 lobe and y5 looks like a non-vtec) ***will post pics***
distributer
ecus (ex=p2p hx=p2n)
throttle body (hx smaller and needed with egr manifold)
o2 sensors (d16y5=5 wire wideband o2 sensor)
engine harness (hx=plug for egr and wired for 5 wire o2)
thermostat housing
exhaust manifolds
injectors(ex=larger injectors also look different)

All of this information was found here (Thanks CheeseWedge!).

And third, to actually answer the original question, according to my HELM manual, the 96-00 HXs use the same wiring harness. If you're going to use the HX harness, you're going to have to figure out what was added to the 99-00 Civic EX's D16y8 that makes them different enough from the 96-98s that warranted a new harness. If there are no changes, the HX harness will work, minus the EGR plug and 5th wire for the o2 (the EX uses 4 wire).

The original question was asked back in January and somebody bumped the thread. The only reason I bothered posting any of this was because I've been having a helluva time finding legitimate answers to my questions and I figured it might be easier for someone else to find in the future.

fleabag

I care because the Civic HX is a rare car and most people who do these modifications are doing it for entertainment value and when they're done with it, they're just going to dump the car like a piece of trash either because they're bored with it now or they so royally ****ed it up beyond belief that they don't know how to salvage it. I'd rather people do this to the vanilla civics than the rare ones since these were designed with fuel economy in mind and I'm sure there are people who could use a good working lean-burn civic.
You don't know what you're talking about.. There are other differences on the HX harness that you don't even know about. The o2 sensor may be a 5 wire but the plugs are completely different since they're an 8 plug design with one pin missing. Also the distributor plugs are also different since the distributor is more advanced than on the other cars. You think you've had a hella of a time, how about me who is trying to do an HX swap into his car but can't because retards think it'd be a sweet idea to butcher up these cars beyond recognition and then just dump the parts that I need when they can't find a use for them. If you want to do a swap, fine but make it a complete swap because there are people out there actively seeking an HX swap and are having no luck because idiots want to make "mad power" with these cars.

gwl

900 dollars for the full rebuild at a well respected place that do motors from muscle cars to imports. I sold it to a friends and it runs great and still get around 40 mpg.

nickcrank

ok the y8 is in and running, the only 2 probs is that vtec and speedo dont work....

Project Dad

check pins on the harness for the speed-o. Mine did not work on my y7 install and I finally found that the middle socket on the harness was half missing like it rusted off. So it was not contacting. Solved with a little tin foil shoved into the socket for now until my new plug gets here.
As for vtec, check out the solenoid

nickcrank

i think im going to switch over my y5 vtec noid to the y8 and see if that solves it but using the y5 ecu, you can tell the fuel map is wayyy dif but on the speed sensor prob, i fixed it with a good beating!!!

nickcrank

ive got vtec working, it hits at 2800 and pulls nice if you just lay smooth into it but if you straight gun it it wants to go in and out... i also almost messed up bad, i forgot to put a clamp back on completely in the back side of the motor and it come off today when i revved it pretty high and i think i drove it only about 4 miles without being full of water.

civek97

Like I said, what do YOU care what HE does to HIS car? It's not YOUR car. YOU do not own, nor drive, nor even know what HIS vehicle looks like. YOU don't put gas in it. YOU don't pay the insurance on it. YOU are completely irrelevant in regards to HIS priorities. If HE wants to do what HE wants to do, so be it. Let him and go on about YOUR business, instead of trying to make HIS business yours.

You're correct, I don't know everything there is to know. But I'm pretty positive the two HELM manuals sitting in front of me do. Thanks for your concern though.

I'm not understanding your grammar. We already know the HX has a 5 wire o2 sensor. And we already know the EX has a 4-wire sensor. It would make more sense to swap the EX o2 sensor with the Y8 manifold to not only get the Y8's 4-wire, but to also get rid of the EGR on the Y5. I personally would use the Y8 distributor in addition to everything else needed. Two people have already done this. Besides, I already stated the distributor and o2 sensors (which would obviously include the plugs) are different. All you've managed to do is repeat what I've already stated without adding anything useful to the progression of solving his conundrum.

I dunno who bullied you as a child, or urinated in your Kool-Aid, or which one of your best friends slept with the love of your life and broke your heart, but you SERIOUSLY need to lose the emotional reactions. It's a CIVIC; it's a hunk of metal, some wiring, glass, plastic and rubber and it'll have the exact same value when it's completely totalled as a totalled Ferrari 458 Italia: nothing. If you're having a hard time in life or whatever it is you have going on, than I'm sorry to hear that. But I'm an adult. I don't disrespect people because they have different priorities than I do. EVERYBODY is having a hard time right now. Your little name-calling does not affect grown folks. Now if you have nothing useful to contribute to the thread, how about taking your negativity elsewhere so other people can actually help him achieve whatever goals he has set for his car. You want to offer insight, that's fine, but don't slide snide comments in at the end. That negates the fact that you're trying to help in the first place. Who knows, the information we're trying to gather here, might help YOU when you finally find your swap.

civek97

That probably would've made all that work you did for naught. lol

Glad you've got it running. You're running a 99-00 ECU?