Choke won't open 100%.. HELP?

[fotosoup]

I know exactly what my problem is.. I just don't know how to fix it. Carbs are new to me, so please explain it as clearly as possible... well here she goes.

Simple.. choke will not open all the way. If I take the metal screen covering the choke in the airbox off and manually open the choke up the engine will idle down. When I don't do that the car will rev at around 2,500-3,000rpm and wont come down (which is bad since I JUST installed a new clutch..)... After driving around all day the choke will SOMETIMES open up completely allowing the car to idle at the normal 750rpm, so it's not an idle problem.

so I need to find out why my choke doesn't open 100%.. it opens more like 90%, enough for the thing that holds the throttle open to stay in place to not let my throttle down.

So 1: I fix the issue with the choke not opening completely
or 2: I find a way to remove the little lobe that holds the throttle open, I can do that with my foot if I have to when it's cold out...

any ideas anyone!?

Oh... and my car is an 86' hatch with the a20a1 motor...

['89AccordLX(Rus)]

I would check to see if the mechanism is gunked up. The fact that it opens sometimes may indicate that the choke heater (bi-metallic spring that actuates the mechanism) is functioning. If the mechanism binds, then you won't see the choke open all the way and the idle will not come down. Soak the crap out of the mechanism with carburetor cleaner and move the choke around by hand to work the cleaner in. Hopefully its as simple as dirt and grime. If worse comes to worse you might have to readjust the choke heater (drill out rivets and rotate the heater to compensate for lack of spring tension). Hope this helps.

[fotosoup]

well I dunno if it's dirt and grime, but what you said about rotating the spring sounds like a good idea.. because the choke feels kinda slack when the car is warm, when it's not open all the way.. once the car is warm and I pull the choke open all the way it idles down, then I can drive it all day and it wont go back up unless it sits for a while.. maybe the little choke heater spring is just worn out? I wonder if replacing it will help any?

['89AccordLX(Rus)]

If you can track the problem down to the spring then it will definitely help to replace it. Of course, rotating the spring is a pretty easy test. The factory position is marked by little hash marks on one of the mounting ears so you can reset it if nothing changes. I've replace the rivets with bolts to allow for adjustment and removal. Also, the little gasket on the spring cover will probably be stuck so you have to be careful when removing the cover.

[fotosoup]

cover?

[VTEC_Inside]

I'm inclined to believe that you have a problem with the bimetallic spring.

Check the wiring to it. Its a single wire that trails off from it down and towards the drivers side of the car.

If the spring was good it would eventually open the choke almost completely by itself regardless if you had a choke puller problem.

If the spring is not recieving power, or is just toast, then the choke puller would be pulling against it to no avail. This sounds likely given your description.

[fotosoup]

so your telling me the bimetallic sping is electrically controlled? That makes sence, because I couldn't figure out what the heck opened and closed the choke. So when the car reaches a certain temperature, the bimetallic spring gets an electrical current sent to it to open up the choke?

Could you please explain to me how the choke system works... Like a series of events that occur to cause the choke to open and close, like for example:

Ignition turns on
Vaccum operates the solenoid that opens the throttle at start up

etc etc... Because I think if I could understand all the workings of the choke system it would make it much easier for me to solve my problem, basically like you have but I want to be able to understand how you came to your conclusion... I'm really new to carbed cars (always have worked on fuel injected so please bear with me!)

Thanks a lot vtec inside, I will go and check to see if I'm getting any signal to the bimetallic spring.

Also, is the choke heater people are refering to the plate under the carb? If so how does this work, does it sense the temperature of the engine and then send a signal to the bimetallic spring? or are they not related.. because that would make sense...

[VTEC_Inside]

People interchange the bimetallic spring and choke heater terms when in fact they are referring to the same thing.

The choke system is in effect very simple.

There is a vacuum diaphram on the front passenger side of the carb that pulls the choke open when the car is running. However it is pulling against the bimetallic spring further back on that side.

When you start the car cold the spring is energized, but is still tensed up providing a lot of resistance to the choke puller, so the choke opens very little at that point.

As the car runs, the spring should start to "weaken" under the current allowing the puller to open the choke further and further until its completely open.

[fotosoup]

ok something I have noticed... the choke puller pulls the choke almost all the way open.. but not 100%... I can pull the choke plate open more than how far the puller will alow it to open (I've pulled the choke puller by hand as far as it goes and it will still not open up all the way)... So, is there any way to adjust the choke so that it pushes the choke open more when at 100% on the choke puller side?

[VTEC_Inside]

ok something I have noticed... the choke puller pulls the choke almost all the way open.. but not 100%... I can pull the choke plate open more than how far the puller will alow it to open (I've pulled the choke puller by hand as far as it goes and it will still not open up all the way)... So, is there any way to adjust the choke so that it pushes the choke open more when at 100% on the choke puller side?

I believe that is correct. The spring should open it the remainder of the way.

[hwcoll95]

i have a similar issue with the 86,drilled rivets snd moved the choke spring to help it open all the way,worked at first then went right back to original fast idle problem,of course try and fix one problem and created a handful of new problems,now have cold morn no start condition,a little starting fluid gets it running,and now recently at cruising speeds,justs starts missing and cutting out,more like an ignition than fuel,with my luck probably both?

[VTEC_Inside]

i have a similar issue with the 86,drilled rivets snd moved the choke spring to help it open all the way,worked at first then went right back to original fast idle problem,of course try and fix one problem and created a handful of new problems,now have cold morn no start condition,a little starting fluid gets it running,and now recently at cruising speeds,justs starts missing and cutting out,more like an ignition than fuel,with my luck probably both?

Take it from me. Moving the choke spring to a position other than the alignment marks just isn't worth it at all. I've tried a few different positions now and just like you, it just causes other problems.

Your best bet is to line the spring back up and rig up some sort of manual choke until you get the problem resolved.