12 replies to this topic

[UltimX]

i'm having a really low idle, about 500 ish. When is the idle suppost to be measured at? After the fan goes off? or when its on? When its on, the idle is around 1k or so, when its off the idle drops to about a smig over 500. Timing is dead set and i heard you can adjust idle with a screw? Is the screw (looking at the pdf on civic manual) on the idle boost diaphram? Somone said it was on the back and i can't seem to find it anywhere on the manual. Plus the fact that the vac lines and everything are blocking the back of the manifold. the only thing i could find on the manual which is a screw on the back is the idle stop screw. Can someone help me? I hate having really bad idle. Thanks!

[DarkHand]

On the US carb, the screw is just below where the throttle cable connects to the carb. It's got a little shroud on it. The screw pushes on the throttle wheel to control the idle. Turning it in increases the idle and loosening it lowers it. Turn the screw in little by little until you get the idle you want. Make sure the car is warmed up when you do this so you're not in fast idle.

The bottom right illustration shows where the screw is, just below the arrow pointing to 'throttle link':

Edited by DarkHand, 13 June 2004 - 11:58 PM.

[UltimX]

Is this the only way to adjust the idle? There isn't a screw like the mpfi cars? Thanks for your help.

[DarkHand]

That's the main method, yeah.

And you said the idle drops when the fan turns off? That seems a little odd, maybe if the alternator was bad, for example, the idle would drop that much when the fan turns on from the increased load, but it's strange that the idle would go up with the fan on, and down with it off.

[UltimX]

Yup. Thats what it does. It idles around 1200 when you start the car. once the fan goes off, the car drops to about 500. Sometimes when the fan goes off when the cars been idleing for a while, the engine just dies. So i'm not sure. In the picture, there are 2 screws tht look like they can adjust it. Which screw do I adjust? The small or the big one? Thanks Darkhand.

Edited by UltimX, 14 June 2004 - 09:44 AM.

[rpr]

On my carb there was a somewhat large black knob just behind the throttle cam/linkage that you could turn to adjust the idle.

[UltimX]

RPR: I was wondering about this "large black nob" because someone mentioned it to me before. I don't know if it makes a difference but does your engine vs. my EW1 have the same differences? As of right now, i'm in the process of looking up the black nob in the service manual on this board. Hopefully i will find this. Thanks Guys...

Ulti~

[DarkHand]

I think that black knob is only on the Canadian carbs. I'm still curious as to the seemingly backwards-acting power load and fan though.

[UltimX]

Yeah, thats what i was thinking also. Maybe its just on canadian cars. Its weird as hell. Why did you think i asked here? isn't idle suppost to lower after the fan comes on though? I mean, initial warm up would have higher idle to warm the car up, after that the idle should drop correct? This is what I was thinking. But this happens all the time the fan comes on. The idle will be high when it comes on, then after it shuts off, the idle drops to about 500 and idles like crap.

Also, RPR, or anyone, where is tha black nob near?

[DarkHand]

There could be a short somewhere, or a ground could be bad/loose. Maybe when the fan is on, the short is able to use the fans ground connection. That's the only thing I can come up with.

[Rampage]

This angle was intended to show the power valve linkage, but you can see the black knob in it...



This is from the driver side of the carb, you can see the power valve dashpot, linkage, one of the vacuum outlets, and behind it all, the black knob that has the spring on it....

This is a canadian carb, and is likely completely different than yours.

My suggestion is to take Darkhand's advice and search for the idle adjuster just below the throttle cable under the little shroud.

Cheers,
Mark

[rpr]

Yup, that's the one I was referring to...I guess it is a CDM thing...sorry...

[UltimX]

I guess so. thanks for your help guys