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Carb Tuning


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#16
deadpool7372

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150DollarRacer -
Props showing what you have done.
This helps with the trouble shooting as well as help us folks that will be undergoing this soon.... biggrin.gif

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#17
150DollarRacer

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Darkhand, I tried your suggestion this afternoon with much success! The car started right up with a huge cloud of white smoke. I am assuming the smoke is coming from the coolant that had dripped into the manifold when I had removed the carb earlier in the day.

I've only run the engine a couple times at 30 second intervals to avoid gassing out the neighbors but so far it seems to be running quite well. At this point I think it is just going to be a matter of adjusting the mixture knob a bit to get it to run better which I will do once the smoke dies down.

Does anyone know what the stock mixture setting is? I am not sure, but I think it was set at about 4 turns from fully closed before I messed with it. The car was originally from Colorado so it might have been set for high altitude usage.

If I am to understand correctly, tightening the screw clockwise will lean out the mixture right? If the car was set up for high altitude then theoretically it should be running lean down at sea leval due to the denser air? If so, Ill probably want to have the mixture knob set at something higher than 4.

Edited by 150DollarRacer, 13 April 2004 - 08:07 PM.


#18
150DollarRacer

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On page 11-32 of the service manual it states:

You may make the followind adjustments to a low altitude car that will be normally driven at high altitude.

...

6. Remove the idle controller bracket and the mixture screw cap from the carburetor, then turn the mixture screw 1/2-turn clockwise.

NOTE: The end result should be no less than 1 full turn from the seated position.


Seated position would mean if you screwed mixture setting in completely? Thus, this would lean it out completely and to avoid that the setting should be at the minum of 1 full turn out, right?

Anything more than that would richen the mixture more, right?

#19
DarkHand

QUOTE (150DollarRacer @ Apr 14 2004, 12:50 PM)
On page 11-32 of the service manual it states:

You may make the followind adjustments to a low altitude car that will be normally driven at high altitude.

...

6. Remove the idle controller bracket and the mixture screw cap from the carburetor, then turn the mixture screw 1/2-turn clockwise.

NOTE: The end result should be no less than 1 full turn from the seated position.


Seated position would mean if you screwed mixture setting in completely? Thus, this would lean it out completely and to avoid that the setting should be at the minum of 1 full turn out, right?

Anything more than that would richen the mixture more, right?

Right, it's basically saying that the absolute leanest you want to run it is one turn out, and that's only for high altitude. You typically need more fuel than that. smile.gif
DarkHand

#20
150DollarRacer

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The hard question though is how much is enough?

I tried running the car right now and it didnt want to idle for some reason. it stayed up around 2700rpm even after the car warmed up. There was a bit of what I think was white smoke coming out the tail pipe and when I tried to shut it off it dieseled for atleast 10 seconds till i slowly put the clutch out to kill it.

As I recall it never dieseled before. My theory is that its running too lean so the cylinders are getting too hot and are burning the old carbon that is probably lining the combustion chamber.

Whats a good starting point for the mixture setting?

Edited by 150DollarRacer, 14 April 2004 - 02:22 PM.


#21
DarkHand

My Civic started dieseling after a while too... The Civic carb is on the CRX now though with no adjustments and it runs just fine, leading me to believe it was an emmisions or vacuum related problem. As far as mixture settings go I can't help there, that's something I've never done. tongue.gif

EDIT: Here's the service manual method for checking the mixture, but it requires a propane enrichment kit.

Edited by DarkHand, 14 April 2004 - 02:40 PM.

DarkHand

#22
150DollarRacer

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Ok so I did a bit of reading and its seems though not good, its not abnormal for a carbed car to diesel if the cutoff solenoid does not engage. On this carb, the cutoff solenoid will engage when the RPMS are below 1400 and you try to turn the car off.

Since Im assuming the solenoid works fine I need to figure out why its stuck in fast idle even after the car warms up.

Any ideas? For those that pulled the emissions junk off, did you have these issues?

#23
150DollarRacer

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Here's a new set of carb picts. Rather than connecting lines this time I used screws to plug them for now.

http://www.engr.ucsb...junk/civic/new/

Hows it look?

#24
deadpool7372

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150DollarRacer

This might/might not help...
Have been following your post to a “T” and, guess what, I have the same problem. biggrin.gif
(Only difference is that I used real plugs... rolleyes.gif )
- The carb is running WAY to rich
- The car idles at 3000+
- The car diesels for 30 sec or so after I kill her

I canNOT find the mixture screw. unsure.gif
(I have read many posts and see picks and looked it up in the manual... I must be stupid!) blink.gif

So...
At least you know that another carb that ran fine to begin with is having the same problem.

- Bad mixture?
- Bad vac hose routing?
- ????

So there we go.
Now what? biggrin.gif unsure.gif blink.gif biggrin.gif
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Tom/RPR: You know you are hardcore when you remove the SEAT COVER!
Lubbock, TX representing. Ya HeaRd! :)

#25
deadpool7372

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Anyone else have an idea?
biggrin.gif unsure.gif
QUOTE
Tom/RPR: You know you are hardcore when you remove the SEAT COVER!
Lubbock, TX representing. Ya HeaRd! :)

#26
DarkHand

QUOTE (deadpool7372 @ Apr 14 2004, 08:17 PM)
I canNOT find the mixture screw.  unsure.gif



biggrin.gif
DarkHand

#27
deadpool7372

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WOW! biggrin.gif
Really, thank you!

That is the first clear explanation I have gotten.
Now to take my carb off again!!!!! mad.gif

Perhaps this will fix the issue???... huh.gif

-Garth
QUOTE
Tom/RPR: You know you are hardcore when you remove the SEAT COVER!
Lubbock, TX representing. Ya HeaRd! :)

#28
clunkycivic

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O.K. I'm gonna ask the newbe question so please forgive me.... I thought that bypassing the smog stuff was very simple (pluging & rerouting some hoses)but after reading this thread I'm confused as heck!!! Would someone be willing to start from the begining and walk through the process of doing this. Plus it would make a nice addition to the FAQ section. Also another thing I would like to know is once this is done what extra stuff (smog related) can you remove from the engine.

#29
DarkHand

QUOTE (clunkycivic @ Apr 19 2004, 11:03 PM)
O.K.  I'm gonna ask the newbe question so please forgive me.... I thought that bypassing the smog stuff was very simple (pluging & rerouting some hoses)but after reading this thread I'm confused as heck!!! Would someone be willing to start from the begining and walk through the process of doing this. Plus it would make a nice addition to the FAQ section. Also another thing I would like to know is once this is done what extra stuff (smog related) can you remove from the engine.

The main procedure is that simple, these guys were just running into a few extra problems.

This thread and this thread should get you through it. smile.gif
DarkHand

#30
150DollarRacer

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Quite honestly I felt those threads really didn't help much at all except for info on the distributor. Just look at these pictures and make your carb look like that:

http://www.redpepper...gallery/albun80

Try this set of pictures as well:

http://engr.ucsb.edu...junk/civic/new/

Everywhere you see a screw is where you need to plug.


Then I found that the idle controller diaphragm wanted to be connected to get my car to idle after warming up. Thats shown in this picture here:

http://www.redpepper...a/aaw.sized.png

I connected that to a vac port on the manifold.

The other tidbit of info is that you need to connect the lower of the two distributor vac lines to a vaccum source.