D16Y8 Intake Manifold on D16Y7 Block and Head---Gasket Leak

Andrewt328

New Member
1. So I have a Y7 block and head with everything else in the engine from a Y8 (manual 5spd). The problem is that i have a vacuum leak in the intake gasket and am getting cel code p0505, which is the IACV error code. Im thinking its just due to the gasket vacuum leak. I have seen many people use a y8 intake on a y7 but not sure why im getting a vacuum leak at the top of the gasket. I am using a gasket set to fit the y8 engine and manifold, but i believe that the y7 gasket is basically the same.

2. My idle is around 1500 rpm and have an occasional haunting idle. I believe this is from the intake manifold gasket vacuum leak. Am i correct?

3. I will drive my car for about 10 mins with it running smoothly. Once it warms up my idle will act really weird. It will bog at 1600 rpm and wont be able to pass it unless i hit down on the pedal. Shifting has to be done at like 2000 rpm in order to get past the engine bogging. Also while in gear letting go or pressing the pedal with the slightest pressure will cause the car to jerk badly. Its like i can either accelerate or decelerate, but not stay at a constant speed. I can relate it to how it feels in first gear when you are pressing and releasing the pedal at very low rpms.

Please any input will be greatly appreciated!
 

CO671

New Member
Registered VIP
Automatic Y8 or Manual Y8. Are you using a 2-wire or 3-wire IACV
 


CO671

New Member
Registered VIP
Andrewt328 said:
Manual Y8...the stock wire one on a 99 civic ex.
Click to expand...
You need an automatic Y8 intake manifold with the 3-wire IACV. How did you go about converting the 2-wire to 3-wire for your Y7?
edit: Pata did a great walkthrough over at D-series, refer to builthatch's FAQ here:
http://www.d-series.org/forums/engine-building/45024-swapping-y8-intake-manifold-onto-y7.html
Patas walkthrough:
http://www.d-series.org/forums/diy-forum/98788-my-y7-y8-intake-manifold-swap-pics.html
 


RonJ

Banned
The 99-00 D16Y8 IM has FIA holes that must be blocked to prevent an intake air leak.

 

Andrewt328

New Member
CO671 said:
You need an automatic Y8 intake manifold with the 3-wire IACV. How did you go about converting the 2-wire to 3-wire for your Y7?
edit: Pata did a great walkthrough over at D-series, refer to builthatch's FAQ here:
http://www.d-series.org/forums/engine-building/45024-swapping-y8-intake-manifold-onto-y7.html
Patas walkthrough:
http://www.d-series.org/forums/diy-forum/98788-my-y7-y8-intake-manifold-swap-pics.html
Click to expand...
both engines were manual engines. I swapped the y7 head and block into my car because i blew a hole in my y8 block. so i am using the same IAVC with same wires

RonJ said:
The 99-00 D16Y8 IM has FIA holes that must be blocked to prevent an intake air leak.

Click to expand...
i think this might be it...my current setup does not even have an FIA control valve. the two hoses that go to and from the FIA control valve are also just not attached. So is the vacuum leak is by my fuel injectors? can you elaborate a bit more on how to block these holes. Thanks

Just found this, i think i might need to block off the same holes? please correct me if im wrong.
http://www.clubcivic.com/board/showthread.php?t=190161
 
Last edited by a moderator:

Andrewt328

New Member
RonJ said:
Fill the holes where the gasket sits with JB Weld. Cap the nozzle.

Here's a more complicated fix:

http://www.d-series.org/forums/diy-forum/110370-diy-deleting-air-injection-99-00-d16y8-intake-manifolds.html
Click to expand...
Thanks.

Lastly, if i currently am using the y8 throttle body and y8 fuel injectors, should i keep my y8 ecu? or should i switch to the y7 throttle body and y7 fuel injectors as well as the y7 ecu? I have all of theses parts (Y7 and Y8: tb, fuel injectors, and ecu) but am unsure of the best combination.
 

RonJ

Banned
You have a Y7 head, so you need to use the Y7 ECU and injectors. Using the Y8 TB with the Y8 IM should be fine.
 

Andrewt328

New Member
RonJ said:
You have a Y7 head, so you need to use the Y7 ECU and injectors. Using the Y8 TB with the Y8 IM should be fine.
Click to expand...
RonJ, you truly are a life saver. Thanks for all of your great help. I will report back with my results.
 

Andrewt328

New Member
Ok so i plugged the holes in the intake manifold...no more vacuum leak, changed the fuel injectors to the non vetc ones to match the new head. But the car idles very low and dies if not pressing the gas. While using the P2E ecu the car will just die and cel reads p1059, which is IACV circuit failure. If i use the old P2P ecu, there are no cel's but the engine still idles very low, turned the idle screw to counteract this, and the car will run on both ecu's, but the P2E ecu has that cel and when pressing the gas the the engine bogs at around 1500 rps (like #3 in the original post). Currently running P2P ecu with non vtec fuel injectors, on d16y8 intake manifold with the idle screw turned about 180 degrees so it idles at about 650rpm. Doing this i hear a vacuum hiss from the cool air intake.

Got any advice for me? Thanks!
 

RonJ

Banned
First off, you must use the P2E ECU. If P1509 is thrown, then there's an IACV wiring issue. How many wires does your IACV connector have? It should be a 3-wire connector for the D16Y7 engine/ECU, so you'll probably have to use the D16Y7 TB.
 

Andrewt328

New Member
RonJ said:
First off, you must use the P2E ECU. If P1509 is thrown, then there's an IACV wiring issue. How many wires does your IACV connector have? It should be a 3-wire connector for the D16Y7 engine/ECU, so you'll probably have to use the D16Y7 TB.
Click to expand...
I believe it's two wires. And yes I am using the y8 throttle body. So if I put on the y7 throttle body, how will I plug in the two prong connector into the three prong throttle body?

Edit: The iacv on the y8 manifold is on the manifold its self as opposed to the y7 intake manifold, which has the iacv attached to the throttle body...
 

RonJ

Banned
What year Civic do you have?

You need to do a 2-wire to 3-wire IACV conversion. Remove the 2-wire IACV connector and get a 3-wire IACV connector from a junk yard. Splice Yel/Blk to Yel/Blk and Blk/Blu to Blk/Blu in the harness to the 3-wire IACV connector. Splice a new wire to the Orn wire in the 3-wire connector and run it to pin A13 in the ECU connector. Repin the Blk/Blu wire at ECU pin A12 to ECU pin A14. Done.

What I describe is the opposite procedure (3-wire to 2-wire IACV) shown in the diagram of this thread:
http://honda-tech.com/showthread.php?t=1243514
 

Andrewt328

New Member
I have a 99 civic ex car. So pretty much put on the y7 throttle body, and use the iacv connected to that throttle body instead of the one on the manifold itself. Should I just take off the iacv from the back of the manifold and just block the holes then redo the wiring to connect to the new iacv which is connected to the new throttle body?
 

RonJ

Banned
Andrewt328 said:
I have a 99 civic ex car. So pretty much put on the y7 throttle body, and use the iacv connected to that throttle body instead of the one on the manifold itself. Should I just take off the iacv from the back of the manifold and just block the holes then redo the wiring to connect to the new iacv which is connected to the new throttle body?
Click to expand...
At this point, it would be easier and better for you to just use the Y7 IM and TB.

Here's the edited IACV conversion for your 99 Civic:

You need to do a 2-wire to 3-wire IACV conversion. Remove the 2-wire IACV connector and get a 3-wire IACV connector from a junk yard. Splice Yel/Blk to Yel/Blk and Blk/Blu to Blk/Blu in the cut harness to the 3-wire IACV connector. Splice a new wire to the Orn wire in the 3-wire IACV connector and run it to pin B15 in the ECU connector. Repin the Blk/Blu wire at ECU pin B23 to ECU pin B6. Done.
Click to expand...
 

Attachments

Andrewt328

New Member
Dang. I don't know if i can get my friend to go through changing the whole manifold again. Already used some gasket sealant also to hold the manifold on and seal from vacuum leaks. It would be easy for me to change out the throttle body. I have all the parts, y7 throttle body with the iacv already on it. All I'd have to do is put that throttle body on it and then redo the wiring, which I would have to redo either way. And assuming that I could just take off the old tb and block those holes. I could do all that work myself and wouldn't require the whole hassle of replacing the whole manifold. And that y7 IM is not a cool air intake one like the y8 I have on it.
 

RonJ

Banned
You should be able to block off the IACV holes in the Y8 IM, if that's what you prefer.
 

Andrewt328

New Member
One more thing. The throttle body is coming from an automatic 98 dx. Will all those sensors and iacv work with my car?
 
You must log in or register to reply here.


Top