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Vacuum Leaks and Carb Parts???

Discussion in 'General Tech and Maintenance' started by JohnDN90, Mar 22, 2009.

  1. JohnDN90

    JohnDN90 New Member

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    My '87 Civic D15A2 CVCC (12Valve) has never idled properly since I bought it. It won't stay running below 1400rpms. Also, if I floor it, once it reaches around 4500rpms it just starts to sputter and has no power. I have a vacuum gauge and it always had very low vacuum, around 10 at the highest (gauge goes up to 30). I tested the EGR valve and that isn't getting any vacuum at all anytime during driving, even cruising on the highway. Something is messed up between the clutch pedal and where the clutch cable is hooked to the transmission, so the clutch won't disengage all the way (adjusting the white nut under the hood, doesn't help). So while the clutch pedal is messed up I decided to rip the carb and intake manifold off the car and clean them good. Now that I have them off, I figured it'd be an easy time to troubleshoot for vacuum leaks. He's some possible ones I've found so far: I haven't been uptown to rent a vacuum pump yet, so I've just been using my mouth and a piece of tube to create the vacuum. All of these test are with the car off and battery removed.

    The Choke Diaphragm Opener- the first hose (from the front of the carb) it is sealed and creates a vacuum, but it doesn't seem to do anything. Doesn't move the opener. The second hose (behind the first), It wont create a vacuum. I can suck on it and open the choke, but it isn't sealed and I can hear a hiss so air is getting in and it isn't maintaining the vacuum. Is this normal or is this a leak I should fix?

    There is a oval/square box thing under where the intake manifold would be in the engine that has a vacuum line that runs from it to the intake manifold- I'm not sure what this is. Is it a vacuum canister? However, from my quick inspection it looks like only that one vacuum hose is attached to it and nothing else. However, when I tried to remove it I took the two bolts out I saw and it still wont come off. Is it connected to the crankcase as an additional breather other than the PCV? If I attempted to create a vacuum in that, it is not possible and I can hear some air hissing into the box. Is this normal or is it a leak I should fix?

    The idle control for the air conditioner (the little black box on the firewall with the red wire running to it)- There are two hoses running to the sides of it. And there is a hole at the top of it. If I suck through the top hose, I can hear air getting in from the hole in the top. It looks like a hose or a cap used to be over the hole but it rotted and broke off, not sure. The bottom hose, if I suck on it or blow on it it doesn't do anything. Is this normal or should I put a cap over the hole?

    The two air bleed valves in the air cleaner housing- the one closest to the front of the car. I use a hair dryer to heat it up and when it gets hot enough it'll open up, but when I suck on the tube the air comes through very very slowly, as if there was just a pin size hole in it, and it also takes a long time to close all the way. The one closest to the driver seat. When I heat it up, it'll open a lot of air will come through, much easier than the other valve, and it also closes and seals faster than the other. Is this normal or is something wrong with the one by the front of the car and I need to replace it?

    The air vent cut-off diaphragm- If i try to make a vacuum, i can feel the air seeping through it. so its not sealed tight on the inside. is this normal or is it a leak I should fix?



    For the carburetor and the idle problem. There is an idle mixture screw correct? Which screw is this? I've been searching through manuals trying to identify them all, but I'm not having luck with some of them. I've attached some links to pictures, could someone let me know which one it is?

    Back: http://i339.photobucket.com/albums/n441/tr...alcon/Back2.jpg
    Bottom: http://i339.photobucket.com/albums/n441/tr...lcon/Bottom.jpg
    Driver(Right): http://i339.photobucket.com/albums/n441/tr...DriverRight.jpg
    Front: http://i339.photobucket.com/albums/n441/tr...alcon/Front.jpg
    Passenger(Left): http://i339.photobucket.com/albums/n441/tr...ssengerLeft.jpg
    Top: http://i339.photobucket.com/albums/n441/tremorfalcon/Top.jpg
     
  2. JohnDN90

    JohnDN90 New Member

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    I couldn't figure out how to edit the last post, so here's the updated version of the last post.

    My '87 Civic D15A2 CVCC (12Valve) has never idled properly since I bought it. It won't stay running below 1400rpms. Also, if I floor it, once it reaches around 4500rpms it just starts to sputter and has no power. I have a vacuum gauge and it always had very low vacuum, around 10 at the highest (gauge goes up to 30). I tested the EGR valve and that isn't getting any vacuum at all anytime during driving, even cruising on the highway. Something is messed up between the clutch pedal and where the clutch cable is hooked to the transmission, so the clutch won't disengage all the way (adjusting the white nut under the hood, doesn't help). So while the clutch pedal is messed up I decided to rip the carb and intake manifold off the car and clean them good. Now that I have them off, I figured it'd be an easy time to troubleshoot for vacuum leaks. He's some possible ones I've found so far: I haven't been uptown to rent a vacuum pump yet, so I've just been using my mouth and a piece of tube to create the vacuum. All of these test are with the car off and battery removed.

    1) The Choke Diaphragm Opener- both connections on it wont create a vacuum. ill hook the hose to one and cover the other with my thumb, but it wont create a vacuum. very fast leak, not a slow one. is this normal or should i fix it?

    2) There is a oval/square box thing under where the intake manifold would be in the engine that has a vacuum line that runs from it to the intake manifold- I'm not sure what this is. Is it a vacuum canister? However, from my quick inspection it looks like only that one vacuum hose is attached to it and nothing else. If I attempted to create a vacuum in that, it is not possible and I can hear some air hissing into the box. Is this normal or is it a leak I should fix?

    3) The idle control for the air conditioner (the little black box on the firewall with the red wire running to it)- There are two hoses running to the sides of it. And there is a hole at the top of it. If I suck through the top hose, I can hear air getting in from the hole in the top. It looks like a hose or a cap used to be over the hole but it rotted and broke off, not sure. If I plug the top hole the top hose will try to make a vacuum, but eventually I can hear something move and it will draw in air from the bottom hose and lose the vacuum. The bottom hose will make a vacuum and sustain it. Should I cap off the top whole where it looked like a vacuum hose used to go or what? I've included a picture of it, see the link below.

    4) The two air bleed valves in the air cleaner housing- the one closest to the front of the car. I use a hair dryer to heat it up and when it gets hot enough it'll open up, but when I suck on the tube the air comes through very very slowly, as if there was just a pin size hole in it, and it also takes a long time to close all the way. The one closest to the driver seat. When I heat it up, it'll open a lot of air will come through, much easier than the other valve, and it also closes and seals faster than the other. Is this normal or is something wrong with the one by the front of the car and I need to replace it?

    5) The air vent cut-off diaphragm- If i try to make a vacuum with my thumb over the hole for the charcoal canister line, i can feel the air seeping through it. so its not sealed tight on the inside. if i try to make a vacuum with the charcoal canister line open, it wont create a vacuum. is this normal or is it a leak I should fix?

    6) The diaphragm on the intake manifold for the coolant- finally got a vacuum pump, and retested all above parts and had same results. there is a small vacuum leak on this diaphragm. normal or should i fix it?

    7) Idle Controller Diaphragm- the line in the front is ok. the line in the rear (closest to the driver seat), won't hold a vacuum. it slowly loses vacuum so its not a huge leak. normal or should i fix it?

    8) Vacuum Advance Diaphragm- The top hose will hold a vacuum. The bottom one however will not hold a vacuum at all. It won't even make it past 0 on the vacuum gauge so it must be a big leak. This isn't normal right?

    9) Brake Booster Vacuum Line- It takes forever for the vacuum pump to build up a vacuum, and even after a long while it only got to around 17, but it held it there. However, if you press on the brake pedal the brake pedal the vacuum drops and it'll drop even more when you let up on the brake pedal. Is this normal or is the brake booster leaking somewhere?

    10) Intake Air Control Diaphragm- with the vacuum pump it only gets up to 7 with fast pumping and it quickly loses vacuum. I assume this is definitely a leak correct?

    I have a picture of a mysterious red wire. I just found it and it must've been unplugged since I bought the car. I have no idea what it goes to, so If anyone has any idea let me know.

    Update: I finally found the idle mixture screw. I was looking for the wrong kind of cap, didn't expect it to me a little piece of metal over the screw.

    Idle Control for A/C: http://i339.photobucket.com/albums/n441/tr...on/100_4741.jpg
    Mysterious Red Wire: http://i339.photobucket.com/albums/n441/tr...on/100_4739.jpg
    Back: http://i339.photobucket.com/albums/n441/tr...alcon/Back2.jpg
    Bottom: http://i339.photobucket.com/albums/n441/tr...lcon/Bottom.jpg
    Driver(Right): http://i339.photobucket.com/albums/n441/tr...DriverRight.jpg
    Front: http://i339.photobucket.com/albums/n441/tr...alcon/Front.jpg
    Passenger(Left): http://i339.photobucket.com/albums/n441/tr...ssengerLeft.jpg
    Top: http://i339.photobucket.com/albums/n441/tremorfalcon/Top.jpg
     
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