Idle Bouncing???

[turbodScooby]

I have a 1997 Honda Civic HX, it's an Automatic, and heres the problems I'm having:

First off, sometimes when I stop at a red light, I'll notice that it wont Idle at one place, it will bounce, and often times it bounces very low, below 1k, never higher than 1.5k, non the less its bouncy, and very distracting.

Secondly, while I'm driving, I'll be giving it a consistent amount of gas, but at certain points like 2.5k RPMs it will sort of bounce up and down, and not consistenly climb, and you can feel it while driving.

Does anyone have any idea what maybe causing this?

[95GSRB18C]

it most likely has to do with a vacuum leak somewhere like maybe where the FPR is or what not. I also had the same problem with the leaks and i had to get my TB gasket replaced too so you might want to look into some of those things.

[turbodScooby]

Whats that going to cost me?

[95GSRB18C]

damn i wish i knew....i would have to say....expect to spend $500 although you might not spend that much because it can vary on diff engines or what not.

[turbodScooby]

ehh Fuck that, I guess I'll just have to live with it!

[stu]

My car does that too, when it is at idle, it dips to about 800 rpm and sits there and gets that bad vibrating feeling. Anyone else have any ideas.

[Bee18c]

Cheap things to do first...

O2 sensor
Clean IACV (Idle air control valve)
check Fuel fliter
Low coolant(It has been proven to promote unhealthy idle, affects IACV)
Also 95GSRB18C vacuum solution too

That's for now. I have been having problems on my b16 also, these solutions had fixed most of the bad problems.

[CSMsi311]

one time i knocked a vacuum line off and it he had a very high bouncing idle. Found the line i knocked off, put it back on, back to normal.

Since i've put the bigger injectors in. I've noticed that my idle is a little rougher. I can feel the engine shake, but the rpm's are steady. I figured it's just a tuning issue

[DnVr]

look on the tb and check if there is a screw then adjust it may be covered by a cap

[stu]

There is definetly a vacuum tube that is disconnected (I think that it's a vacuum tube) because the guy that put in the custom CAI just left some stuff unplugged and/or barely connected. I should take a picture of it. It is a thing that is right after the throttle body that says "up" on the top of it.

[Mr. NoSkills]

To check for a vacum leak, just take some carb cleaner or something, and spray it around all the "joints" and vacum lines.
If the car surges up, that's the spot that's leaking.
It could also be a coolent bubble, just "burping" the system might fix it.

You might wanna try that stuff, save you the $70-$90 fee a dealership will charge just to look at it.

[Mr. NoSkills]

Originally posted by stu
There is definetly a vacuum tube that is disconnected (I think that it's a vacuum tube) because the guy that put in the custom CAI just left some stuff unplugged and/or barely connected. I should take a picture of it. It is a thing that is right after the throttle body that says "up" on the top of it.

If your talking about what I think you are, it's just a little dashpot that really does nothing. If you take alook you'll see it has an arm comming off and going to the throttle body, it's to kind of keep the idle steady.
Like hook up a strong air source and watch the idle climb.
I'm not sure if were talking about the same thing, but if so, it's not a big deal at all.
Also, 800 should be right, that's like the stock idle rpm.

[stu]

Originally posted by tdjb-potc
If your talking about what I think you are, it's just a little dashpot that really does nothing. If you take alook you'll see it has an arm comming off and going to the throttle body, it's to kind of keep the idle steady.
Like hook up a strong air source and watch the idle climb.
I'm not sure if were talking about the same thing, but if so, it's not a big deal at all.
Also, 800 should be right, that's like the stock idle rpm.

Thanks, if I hold my finger over it will the idle drop? I might have to try this. *Stu is going to go start his car and start blowing into a tube*

Oh yeah, I don't know where the other end of this tube is supposed to go. Here is a better way of explaining it. When you do a CAI conversion, there is the assembly that goes from the beather on the head to the intake, and from the throttle boddie to another coolant source, and then there is another tube, and that last one is the one that is unplugged still.

[ShervRacer]

Originally posted by turbodScooby
I have a 1997 Honda Civic HX, it's an Automatic, and heres the problems I'm having:

First off, sometimes when I stop at a red light, I'll notice that it wont Idle at one place, it will bounce, and often times it bounces very low, below 1k, never higher than 1.5k, non the less its bouncy, and very distracting.

Secondly, while I'm driving, I'll be giving it a consistent amount of gas, but at certain points like 2.5k RPMs it will sort of bounce up and down, and not consistenly climb, and you can feel it while driving.

Does anyone have any idea what maybe causing this?
this happend in my friends upgraded civic 95 4dr... i noticed the car kept going VROOM VROOM VROOM bouncing rpm's... he told me its nothing... his mechanic told him that happens sometimes when you dont let the car warm up well... the fluid is cold at some parts and hot at others and the computer gets confused that the liquid keeps going... so the car wack. but it only happend once when i was in it... he also told me it happens more on REALLY cold days... because he isnt patient enough to warm the car up.

[ShervRacer]

ny friends car was going from 600rpm to 2k rpm up and down really fast...

[Kwando]

My prelude use to do this until Tobi did a timing belt change on it.

[Dallas J]

Do like us DSMers. Find something to cap off the intake and put a shrader valve in it. Then pressurise the intake track. Not too much of course. Then listen for leak, Fix, and run like a champ..unless thats not it.

Another thing to try is some Mopar Combustion Chamber Cleaner(MCCC). Clean your TB. Check for exhaust leaks.

-Dallas J

[WagN2NR]

WOW, this is the 4th time iv seen this problem on HAI...