How To: Y7 To Y8 Intake Manifold Swap

Status
Not open for further replies.

oc_civic

....................
Registered VIP
Registered OG
5+ Year Member
10+ Year Member
D16Y8 intake manifold swap

If you plan to keep the Y7 computer, it's easiest to use a Y8 auto manifold and t/b since the IACV setup is the same. Of course the 5-speed manifold setup works fine too, you just need to block off the IACV opening on the back and swap the throttle rotor & spring over to your Y7 t/b.
If you use the Y8 injectors with the Y7 ecu, you will run rich though so you want to reuse your Y7 rail & injectors. Here's a rundown on how to do it, this is everything I can remember off the top of my head...sorry if it's long-winded!

Here are things to have on hand when you start the project, so you won't have to leave for the auto parts store during the middle of it:
new intake manifold gasket
Y8 manifold brace
about 5ft of 1/4" i.d. hose, suitable for fuel/vapor/coolant use.
about 2ft of 3/8" i.d. hose, same kind of stuff
premixed coolant for aluminum blocks (you're going to lose some!)
*you might want to change PCV valve while manifold is off, it's not easy to get to otherwise.
*if you've got lots of miles and never did fuel filter, nows the time while system is depressurized also.

1) Remove fuse to fuel pump, then start car. When it stalls out, turn it off and remove the negative battery cable. This is to relieve the fuel pressure. Put the fuse back so you don't forget later.

2) Pull out the IAT sensor from the Y7 airbox, remove the box & piping, Also remove the little throttle cable brackets and detach the cable from the t/b and the cable stay.

3) Put some masking tape on the injector branches and mark them 1-2-3-4 so you get them back on the right ones, then pull the plugs. Loosen and remove the fuel hose nut at the fuel rail inlet.Take off the 2 nuts holding the fuel rail on, also I think the harness clips in a couple places on the rail so unhook those clips. Pull the little hose from the regulator to the manifold then lift out the rail/injectors. (If reusing Y7 injectors, install them in the Y8 rail, or just move the Y8 purge solenoid from the Y8 rail to the Y7 rail.)

4) Remove all vacuum lines from the manifold to any other sources. Get some rags and cups handy, now you start unhooking coolant lines! Use some pliers or channel locks to pull the retaining clips down the hoses a bit, then start pulling the hoses off. Splash! Just try not to get the coolant into the injector holes.

5) Using the outside-in pattern, loosen & remove the bolts holding the manifold to the head. There's one bolt on the underside of the manifold that holds the brace onto it, I think it's an 12mm. Grope around for it and remove that too. The manifold should be able to come right out now.

6) remove the old gasket, without gouging the surface underneath. This is tedious and irritating, at least for me it was. It's easy to scratch the head, so if you've got some chemical to soften the gasket up that would be good. Remove wiring clips from the manifold brace, take the brace out too.

7) Get your new PCV valve ready by installing the 3/8" hose & clamp on it. Don't put it in yet...first, remove the small hose from the water pipe right near the PCV (this one is a gusher!) Have a stretch of 1/4" hose ready (15-18") ready to put on immediately. This coolant line will go to the IACV on the Y8 auto t/b, just like it did with your Y7.

8) If the head is cleaned up, put your new mani-gasket on and slide the head into place. Hand snug the bolts up, then start torquing them properly in order. Once it's tight, put the Y8 brace in place and tighten it to the manifold first, then tighten the bolts to the block. If you have a header or downpipe made for Y8, you should get an exhaust support brace for the Y8, it is held on under the manifold brace by the same bolts. It is oriented properly for the support bracket you see by the header collector area on Y8. Y7 is different for some reason.

9) Reconnect the fat coolant line, run a new piece of 1/4" from the IACV to the small nipple that comes off the big one. Cut the new coolant line coming from the pipe under the mani to proper length and connect it to the other IACV nipple.

10) Lightly oil the rubber injector seats, then with the injectors already in the rail, install the rail with injector connectors facing up. Tighten it down, then connect the fuel supply line and tighten it up (don't forget the washer).

11) Use another length of 1/4" hose to run from your purge cannister to the purge solenoid on the rail, then connect the other end of the PCS to the medium sized port under the larger one on the front of the manifold. the upper one is for the PCV 3/8" hose. Now push the PCV down through the hole by the middle manifold nut, go underneath and connect it to the black box. Back up top, route the PCV hose to fit the port & cut to length.

12) I think all the wiring will reconnect without modification except the PCS connector, you might have to lengthen it by 6-8". Reattach the tiny hose from regulator to the little port right near the t/b. Use a small piece of that little hose with a screw in it (or just some silicone) to block off the cruise control vac port on the back driver side of the manifold. Connect the brake booster hose to the big port on back.

13) Plug the wiring back in, make sure you don't mix up the MAP & TPS, they are the same kind of connector. I marked all connectors before removing them just to be sure.

14) Install the cable into the throttle rotor, insert it into the stay, & tighten it up solid with 2 12mm wrenches. Make sure there's no slack but that the rotor isn't open at all when not stepping on the gas.

15) After double checking to make sure everything is hooked up, and you have not crossed and coolant/vac lines, reconnect the battery cable and crank it over. It will take a few seconds to pressurize the fuel system again.

I think that's everything, it should make sense when you are looking it all over and start working on it, this should be a good guide. Hope it helps!
 
Status
Not open for further replies.


Top