Ricey McRicerton

Hey guys...I'm mid project right now, and could'nt figure out where my vaccum leak was coming from until this morning. I apparently do not have a y8 manifold like i thought. Ive checked my helms manual, and all of the diagrams show the y8 mani with an indented top (kind of like mountains). The intake manifold that I have has a nipple in the center of the front (just on top of the surface that mates to the head) sticking straight up, and some smaller ports underneath that. I'm almost positive that is my problem, but does anyone know what kind of mani it is?? Any ways to make it work on my y7??? Thanks!

Ricey McRicerton

Maybe I should clarify more. This is a y7 head and block, but Im putting the y8 intake mani on it. Can some of you guys post pics of your intakes on the y8 manifolds??? Im having questions about one nipple on the top of the IM right infront of the fuel rail. Someone has to have done this and know!

xXx Justin xXx

ummm... i COULD be wrong. but my friends 2000 civic ex (has a y8) has a nipple infront of the fuel rail. right in the middle of the head.... going striaght up.. but it is supposed to be hooked up to like a hose for ventalation i think? kinda like the ones on tha z6 and a6... that pipe connected to the one that comes off of the valve cover... goes from the head, to the bottom of the IM. my friend has his hooked up to a catch can though? i think it is just for ventalation though...not vacuum. if you could post a picture i would be able to see if it i sthe same one i am thinking about.

Ricey McRicerton

yeah thats the nipple im talking about..the one that goes striaght up. I think it goes down into smaller holes in the IM though, because I have a serious vaccum leak around the top of the IM where the head and it mate....i can hear a strong wistling coming from the back of the block where it meets the IM. With the y7 head, the valve cover almost meets up with the top of the y8 IM and there is a heavy vaccum leak somewhere in there. I know the IM is square and the gasket is seated good...anyone who did this project have any suggestions??

EDIT: Id post pics, but I dont have a digicam...

Ricey McRicerton

bump one more time before bed...I really need to knwo this!

SixPAK

Tape up the hole and see if you can get rid of the vacuum leak. If not then take the injectors out and use eletrical tape to tape around the injector...you will see where there is a hole on the injector.

Ricey McRicerton

THANK YOU!!! So what your saying is that the injectors have a small hole in them that causes the leak??? Ive already tryed plugging the nipple and it wont solve the problem.

xXx Justin xXx

ummm.... injectors causing a vacuum leak. the car wouldnt idle correctly if the injectors were leaking at the o ring. just search around for all holes and nipples on the back side of the head, the IM ... wherever. there are a few different ones scattered all over the place. and that nipple you just where talking about. if you covered it and it didnt change anything.. that is bc it is for ventalation like i said...you can just slap a breather filter on that or hook it up to a catch can or something? you dont have any friends that have a 96-00 ex civic? go to your local cruse spot and ask somebody if they can pop their hood for you. this should be very easy to solve man.

granada_sun

Make sure the mani was installed by tightening the bolts from the inside out, alternating back and forth....that can cause leaks as well....

Ricey McRicerton

I tightened all the bolts like that from the inside out....I put a hose on the nipple, and when I blew in it, my idle dropped back down like it should be...can anyone post a pic of a y8 mani on a y8??? Thanks!
p.s. None of my friends have a ek with a y8 in it for me to look at...sorry...

EDIT: I pulled the injectors today and there is a small slit in the top of the injector hole??? It isnt on my y7, and I think it may lead to the small holes in the face of the manifold...how should I try to plug them (except for tape maybe, or is tape really okay)??

HndaCvcRcr

Here's a link to a website where they install the D16Y8 manifold onto a D16Y7...

http://www.makuragi.s5.com/civic_99/Y8maniswap/

hope that helps some...

-Blake

Ricey McRicerton

Apprecite it man, but thats the site I used as help to put it in the first time, Ive narrowed my leak down to the top of the mani, but can't seem to get a straight answer as to wether my mani is not a y8 (because the Helms manual shows a diff mani) or I need to do something differenty to make my mani work... Dang this honda stuff is frustrating sometimes!

Quad-Damag

Thats the one i used when i changed my D Series

**** it dosn't talk about

D16y7 the stock tb won't work, I used my old one, but i used a 92-95 EX spring, becuase the stock dx tb, moves the wrong way and the stock ex moves the right way. They are the same size, but i would rather use a 00 DX TB and not a 92 EX TB, which i wasn't even sure if the sensors worked.
You are also going to have to custom mount your DX TB Cable if u want to use it, i would get a EX TB, it will make it so much easyer.

I also did a aftermarket D Series Manifold and not a direct y8 swap.

It's a Focus 2 Intake Manifold.

SoyaBean

I had the same problem, I put on a 99 Y8 Intake Manifold on my 99 Y7 block. I kept having the surging idle problem in which is the cause from a vacuum leak. I plugged up that little nipple that you're talking about and the cruise control port on the back of the intake manifold, but I still encountered the idle problem. I went back to the Y7 IM and sold the Y8 one. I been told that using a 96-98 Y8 Manifold will work as it doesn't have that nipple in the middle.

HndaCvcRcr

man I've been thinking about doing the same thing on my 99 LX, which has the D16Y7 engine.

Ricey McRicerton

Yeah I ended up making my own little Throttle Cable bracket, but they acutally did adress the spring not turning the right way. I just dont think that I have a y8 manifold, unless it was changed over the years...I also used my stock TB so that I wouldnt have to mess with the IACV 2 wire to 3 wire thing!

Ricey McRicerton

Yes, I believe it was a 2000 or a 99...not really sure

Ricey McRicerton

okay, ive narrowed it down to a 2000...the 96-99 helms manual I have says that all the Intake Manis DO NOT have the common rail across the top. Can anyone checek for me on a 2000 ex and tell me where the nipple goes to???

civic-4-ges

I just did this swap and came up with the same issue. Don't worry about that vacuum connector sitting against the head on the top, thats not your problem. There are little holes right above your ports on the mating surface of the IM. These need to be plugged. They are close to an 1/8" Diameter and they suck in a lot of air, obviously audible. This is what caused my problem, plugged them up and works perfectly. Contact me if you need any tips.

Marauder

The D16Y8 manifold from 1999 and 2000 have air-injection. To put that manifold on a Y7, you need to plug each small hole from the flange to the fuel injector. If you do not, you will always have a vacuum leak there. If you only plug the nipple in the center of the flange, it will not do a damn thing. Take the manifold off and fill that tiny hole with epoxy, or better yet weld it up.

Since the Y7 head is not meant to seal that area, that little hole stays open to the atmosphere and lets a small amount of air into the manifold from around the fuel injector area.

The air-injection feature on the 99-00 civic ex's are just a cold start emissions thing.

HndaCvcRcr

so if you were to change the head also to a Y8, it would take care of those holes and you wouldn't have to worry about plugging them?

Marauder

Only the 99-00 d16y8 head would seal that intake with the intake gasket that goes with it. Then all you would need is to cap the nipple in the center of the flange.

HndaCvcRcr

Is this the nipple your talking about in the center?(red circle)



If so, where is it supposed to go? Just trying to gather info so when I do this to my engine, I know what to expect

Marauder

Yeah, that's the nipple. In the 99-00 civic EX's there is a hose that runs from the airbox to a thermal switch in the thermostat housing, and another hose from there to that nipple. You can see in that pic, the intake gasket has a slot above the intake ports, that slot seals the air-injection for the 99-00 civic's.

I would suggest that if you are mini-me conversion....stick with intake manifold without air-injection. The head doesn't matter, just don't run the intake manifold. Better yet.....get the Edelbrock intake manifold that's going to come out soon, it comes with plugs so you can install it on a civic with air-injection, or use the supplied plugs when you install it on a car without air-injection. But that manifold isn't supposed to be on the shelf for a couple months.

Ricey McRicerton

I ended up just JBWelding those holes shut...problem fixed! Also, yeah I figured out that the nipple didnt go to anything either...thanks a lot for your help guys!
ps. Honda's computers (in the parts department) don't show that port on the top either