Shaking at stop and terrible gas mileage! HELP!

wagovanloverwagovanlover New Wagonist
in Engine & Drivetrain
Okay I have been to a couple different "Honda specialist" and no one can tell me whats going on or try to even help me.

I the stock D15b2 and I havent done anything to it except added a cold air intake but it was having these problems before it. All I know is it shakes and the idle fluctuates sometimes when sitting at idle in every gear (automatic). Also im guessing this is making my other problem which is pretty bad gas mileage. Im getting about 25 mpg with my best being about 27 mpg and I dont drive fast or slam down on the gas.

So far I have checked the idle air control valve and injectors and they seem to be fine. I also replaced the fuel filter which was terrible. I had a mechanic do a valve adjustment which didnt seem to help at all even though they swore that was the problem. They did it while the engine was still pretty hot which I was told recently that your supposed to do it while its cold like really cold! Could that be the problem? maybe the adjustment didnt take because of the heat? Also the dumb mechanic told me that on these old Honda engines your supposed to hear the valves but before I couldnt and now after the adjustment I can but it seems like such a good small engine should be quiet (like it was before the adjustment).

I dont know what to do. Please help

I know my rear engine mount is going bad but the other two are new. Also I think there might be a very very small leak in the intake manifold gasket.

Oh also when you pull the wire off the number 3 plug there almost no change at all in the idle which is really weird to me. Because of that I had multiple compression checks done on all cylinders and everything was great (which makes it more confusing)

Any ideas are greatly appreciated!

Comments

  • SIllyWagonSIllyWagon Band Wagon
    Does #3 cylinder have spark? Few things you can do is, pull the spark plug out of #3 and plug it into #3 wire, now you need to ground to plug by holding it to like the vavle cover nut, with someone cranking it, does it spark? If not, if you have a volt meter, take #3 spark plug wire off the distributor, inplug spark plug an check for resistance, if your readings are above 150ohms, (dont quote me on this) or showing no resistance, OL, than the wire is bad, change all 4. If that isnt the case, than check your distributor. But it sounds like an intermitent miss in #3 cylinder, which would cause 1. Richer A/F 2. Sporadic idle 3. loss of power during accelaration. I would check the easiest first, like I always say KISS, (Keep it simple stupid)
  • Jimmy427Jimmy427 Band Wagon
    that small vacume leak could have turned into a big one sounds to me that way specily if it killing #3
    definet vacume leek or a bad injector on # 3 switch 3 and 2 if it moves then thats the prob if not
    spray carb cleaner around the intake gasket and all hoses or gaskets to intake if engine revs up or even dies there is your prob
  • wagovanloverwagovanlover New Wagonist
    Shoot I forgot to mention a few things. I have new plugs, and wires, cap, rotor and coil pack. So I know that's not the problem. And I'm guessing it's not the injectors because I have the old duel point injection so there is only two injectors on the the intake manifold. Thanks for the replies though. Any new ideas?
  • SIllyWagonSIllyWagon Band Wagon
    Like Jimmy said, vacuum leak, check the Purge Control sensor, Its a black looking thing with a circular top, (horrible Discription) on the firewall, usually inbetween but above the fuel filter, and intake. Also, maybe check your fuel pressure regulator? I test it by taking one vacuum hose off, and putting my fingure over the hole, than push in the regulator, if you feel pressure, its good! What is your idle sitting at? Does this happen a lot more with your AC on?
  • 1sleeperwagon1sleeperwagon Wagonist
    Wagovanlover,

    As many honda's that I have worked on valve adjustment COLD, not say all but most as far as I know and I don't know everything. Like Jimmy427 says check that vacuum leak that could be a bigger problem that just a small leak!

    Did it just start doing this or did it just apeared one day. Thing we need to know to help you. I hate to say this but its turn just because its new parts doesnt mean its good. (new puppys die to) as much as I hate to say

    Does it do it all the time?
    Does it smoke (sometimes all the time?)
    Does it have a check engine light?
    Are the RPM higher than normal at idle?
    Compression checks hot cold with small amount of oil in the cyl or not?
    When they pull the spark plugs did they look ok or did they have lots of oil, fuel, or oil deposite?
    Did they do a leak down test on the cyl to check if its rings, valves, valve guides.
    Any other noises that come about.

    Check on these and let me know, I will help as much as I can. Any question just ask :)
  • wagovanloverwagovanlover New Wagonist
    I'm typing on my phone so I hope I don't forget anything.

    The shaking and bad fuel economy is consistent (I replaced a broken pcv valve yesterday and it helped a little)
    It doesn't smoke at all.
    There is no check engine light, and there never has been.
    It idles pretty high when warming up which is normal but then it drops to like 500 rpm once it's warm.
    The compression checks have all been good and have been done by multiple mechanics, and there hasn't been any oil in the cylinder.

    Because it's running rich for whatever reason there is some fuel deposit on the plugs but no oil.
    I'm not sure if they did a leak down test but since all the compression tests were good I didn't think it needed on.
    There are no weird sounds

    The car over all runs great but the shaking and bad gas mileage is confusing.

    I'm going to try to clean the throttle body, intake manifold and iac today
  • 1sleeperwagon1sleeperwagon Wagonist
    wagovanlover wrote:
    I'm typing on my phone so I hope I don't forget anything.

    The shaking and bad fuel economy is consistent (I replaced a broken pcv valve yesterday and it helped a little)
    Take the valve out and put your thumb over it and see what the rpm do and also check the hose for that.

    It doesn't smoke at all.
    GoodThere is no check engine light, and there never has been.
    Good

    It idles pretty high when warming up which is normal but then it drops to like 500 rpm once it's warm.
    500 seems low I thought it should be 700-800 but on 100% check the sticker on the hood. If it is still there.

    The compression checks have all been good and have been done by multiple mechanics, and there hasn't been any oil in the cylinder.
    Just because the compression is good does mean its all good. The little oil in the cyl. when checking the compression will tell you if the rings are good. And as far as multiple mechanics go they have not fix your problem! Not saying they are doing a bad job.
    Because it's running rich for whatever reason there is some fuel deposit on the plugs but no oil.
    Good and bad this could be the sign of the small vacuum leak
    I'm not sure if they did a leak down test but since all the compression tests were good I didn't think it needed on.
    Leak down checks alot of things google it. Just to see so you know what what the mechanic is either talking about or BSING you
    There are no weird sounds
    Good
    The car over all runs great but the shaking and bad gas mileage is confusing.
    When you take off from a light or anystop does it spudder and then clears up after so many rpm's
    I'm going to try to clean the throttle body, intake manifold and iac today
    Thats good let me know.
    Hope this helps
  • jasnalljasnall Wagonist
    Adjust the timing by twisting the distributer. Wait until the car is warmed up then move it whatever way makes the rpm go up. I think I just saw in my service manual that the idle speed should be between 550-600. Since he's running rich he could advance the timing right? I know on my buddy's car raising the idle through either the idle screw or timing helped with the shaking.
  • wagovanloverwagovanlover New Wagonist
    Ill try the things you guys said today and get back to you.

    oh and my car never sputters or has a loss of power, thats why this problem is confusing too.

    im gonna adjust the idle speed and see what happens
  • wagovanloverwagovanlover New Wagonist
    also yesterday i noticed that the original wires that go into the fuse connector for the o2 sensor are barely hanging on. About half are cut and the wires are all showing. The o2 sensor is pretty new but if the wires are all messed up could that screw up the signal to the computer and make the fuel mixture richer?
  • SIllyWagonSIllyWagon Band Wagon
    wagovanlover wrote:
    also yesterday i noticed that the original wires that go into the fuse connector for the o2 sensor are barely hanging on. About half are cut and the wires are all showing. The o2 sensor is pretty new but if the wires are all messed up could that screw up the signal to the computer and make the fuel mixture richer?

    Yess!!! But idk at the same time because you said the CEL. But things like that all play a role. I had a similar problem, especially with the AC on, but my CEL came on going 75 when engine was warm. O2 sensor fixed that. My thought was it wasn't going into closed loop.
  • wagovanloverwagovanlover New Wagonist
    yeah i never get a check engine light because the problem isnt that bad. But i think your right about the o2 sensor. Im gonna change it or rewire it.
  • jasnalljasnall Wagonist
    Possibly, to be safe you should fix the wires. Bad O2 data can mess a lot of stuff up.
  • Jimmy427Jimmy427 Band Wagon
    did you spray the intake you are gessing at prob think small first more than likely you do have a vacume leak
  • wagovanloverwagovanlover New Wagonist
    So after doing some research i found out about a "wonder" product call seafoam haha. I bought some and put it in the tank and in the oil like it said. It amazes me that something that smells like vodka and soap can be put in both oil and gasoline.

    Also I got some carb cleaner and cleaned as much of the intake as i could and i did find a vacuum leak. There are two very small hoses coming off the back of the intake right next to the throttle. Hopefully someone knows what im talking about. One has a yellow stripe on it. Anyway the one with the yellow strip seems to have a vacuum leak judging by the fact that the engine bogged down when i sprayed on it. I dont know what that specific hose does though.

    Anyway after a decent cleaning and some idle adjustment it does run better. After this tank ill see if my mileage gets better.

    It still shakes a little but i figure after a little more cleaning, a rewire of the o2 sensor and the rear motor mount it should be almost gone.

    To anyone that would know, Should I still do a cold valve adjustment? The slight clicking bothers me
  • SIllyWagonSIllyWagon Band Wagon
    Don't forget after 50 miles, you gotta change the oil! =]
  • WagShapedProjectileWagShapedProjectile New Wagonist
    wagovanlover wrote:
    So after doing some research i found out about a "wonder" product call seafoam haha. I bought some and put it in the tank and in the oil like it said. It amazes me that something that smells like vodka and soap can be put in both oil and gasoline.

    Also I got some carb cleaner and cleaned as much of the intake as i could and i did find a vacuum leak. There are two very small hoses coming off the back of the intake right next to the throttle. Hopefully someone knows what im talking about. One has a yellow stripe on it. Anyway the one with the yellow strip seems to have a vacuum leak judging by the fact that the engine bogged down when i sprayed on it. I dont know what that specific hose does though.

    Anyway after a decent cleaning and some idle adjustment it does run better. After this tank ill see if my mileage gets better.

    It still shakes a little but i figure after a little more cleaning, a rewire of the o2 sensor and the rear motor mount it should be almost gone.

    To anyone that would know, Should I still do a cold valve adjustment? The slight clicking bothers me

    This may sound stupid (or someone has mentioned it) but, it happened to me: Check all your ground wires! If they look bad, then they are bad. I couldn't pass Emissions because of a bad ground. We put my wagon on a Snap-on scope, and it makes a massive difference whether or not you got a closed loop.
  • wagovanloverwagovanlover New Wagonist
    I know some of my ground wires are pretty beat up and you may be right. I'll put that on my list of things to do. Thanks
  • TheGmanTheGman Wagonist
    Seafoam is great, i poured some straight into my dual point manifold. Didnt help because i had bad rings, but its worked on other cars i've had haha
  • wagovanloverwagovanlover New Wagonist
    Well after replacing pcv valve and taking our and cleaning the iac valve and egr valve nothing changed. Then to my surprise when I got close enough to the intake manifold I heard a hiss. Then I found it, a huge vacuum leak from a small hose that comes off the intake manifold up to the base of the intake where the throttle is but right above it. It's about a six inch vacuum tube that had about a half inch hole in it. I can't believe I never saw it but it was on the bottom. So $1 worth of tube about two seconds to install and now it runs perfect. I don't know what that vacuum line is for but Geez its important. :-)

    Thanks everyone for your help!
  • Jimmy427Jimmy427 Band Wagon
    wow if you did what i sugested in the begining would have saved you the time and headache.
  • 503Wagon503Wagon moderator
    Jimmy427 wrote:
    wow if you did what i sugested in the begining would have saved you the time and headache.

    hah lol.
  • wagovanloverwagovanlover New Wagonist
    Your right man. I did do what you said, I sprayed carb cleaner on the intake but I guess never on the under side of that little hose. Well either way I'm glad it's fixed and I'm sure it will be even better since I fixed those other things too. Thanks
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