Few questions about carb parts, answered.

[A20A1]

Workin on my keihn today and swapping some more parts from the parts car and I busted a plastic port on this piece of the carb. I dont have pics so I'll do my best to explain it...
Looking in the engine bay from the front, the back left of the carb has this piece that looks like it has something to do with the choke, not to be confused with the one that actually DOES move the choke piece (front left of the carb). The plastic port I broke is the "functional" one, meaning when you put vacuum to the other one it doesnt do anything, but if I put an open vacuum line next to the piece thats broken (so its getting vacuum to the broken piece) I can see and hear this metal piece move but it doesnt seem to move anything else, it just *click* and thats it.
Right now I have no vacuum going to it at all, its useless if I put it on the other port because it does nothing.
My question is what is that piece and what does it do? It also looks like it has some wires going into it and a rubber plug/cover.
**And if you can, answer these aswell: The "temperature sensor" or whatever its called on the intake that has the clip you can unplug, what does it do exactly? Is it needed for anything? It was running fine with it unplugged and running open carb while I was playing around with things.
And finally #2, Why does the front choke diaphram/puller or whatever have 2 ports? If you connect vacuum to either one it bleeds to the other one and you can feel suction on the open port, doesnt seem to make a difference whether its connected to one and the other plugged, or both connected. Whats the deal?
Appreciated mike

#1
- Sounds like the Fast Idle unloader (Plastic Ports Near Choke)
- The Electric Choke (Wires With Rubber Plug/Cover)
- That Temp Sensor is hooked to your Coolant Temperature Gauge in the dash.

#2
The second port on the Choke Puller is a Black Box controlled solenoid/vacuum-bleed to help adjust the choke opening when cranking/starting the engine.
You can see where it connect to by looking at the diagram here:
http://www.3geez.com/forum/showthread.php?t=45880
If its not hooked up then plug it.

[FyreDaug]

Thanks for the info, but clear this up for me then.


Sounds like the Fast Idle unloader (Plastic Ports Near Choke)

Meaning what, when it gets vacuum it is supposed to unload the fast idle? Because I had it not hooked up to anything and the only way to drop fast idle is to kick it down, it wont do it on its own, or when you connect vacuum to it.

The electric choke, is it temp based? Because I know the only way to kick down the carb is to hold the choke all the way open and blip it, sometimes the choke isnt open all the way and it wont kick down unless its totally open (which btw I tried removing yesterday and couldnt get the damn plate screws out.)


That Temp Sensor is hooked to your Coolant Temperature Gauge in the dash.

??? Im not sure we are talking about the same thing... if so thats wierd. Its the one in the intake tube, the temp inside the car still worked when it was unplugged

And as for choke puller that makes sense, they are just both hooked up to vacuum at this time

[A20A1]

Did you see my how to on removing the plate screws? you may need to carefully pinch the screws with a nice pair of vise grip needle nose clamping pliers.


The wire to the choke is the choke heater. There are a few ways chokes are heated... one way is with electricity, the other is with coolant. Ours is an electric choke.

The choke and fast idle work on a cam linkage system... there are grooves or steps in the cam to set different stages in the fast idle rpm as well as the choke opening. I think there is more then just vacuum controlling the dropping of the fast idle... I'm pretty sure you need the choke to be heated as well before the fast idle can drop. If you're opening the choke manually, then you're forcing it to go where it would be when the choke is heated... so then that allows you to drop the fast idle. Honestly if you're not going to have vacuum to the fast idle unloader and are doing who knows what with the choke, you might as well remove them both.

Plug the other port on the choke puller...
That port already has vacuum of its own... it uses an internal vacuum line thru the carb... that port was used to bleed vacuum to the black box. I mean you can run it the way you have it but I think it's a waste to do it that way.

Oh the intake temp sensor...you don't need that.. I removed it even before I did the vacuum removal... you don't need it at all if you do the vacuum removal.

Lostfforawhile should be able to give you more in depth view of the choke and fast idle. If you want to keep those things.

Honestly I'm tired trying to fix everyones problems when they do the vacuum removal. It's supposed to remove all the components, not just some of it. And you're supposed to do it on your own. All I had to do was show everyone where to connect vacuum line #2 and #14, and have them plug everything else (*Exception ABC air jet tuning between CAN/US models).
The vacuum removal was supposed to get rid of all the problems... not make more.

[FyreDaug]

Oh an believe me it solved all the problems and the car is running like a champ, I just wasnt sure how some of the things worked, and why. I didnt even use the vac removal diagrams this time, I just hooked up what I knew worked and wanted to see if I need the fast idle unloaded. I will try removing the choke puller aswell just to get rid of more vacuum crap.

I know on the OBD cars the intake temp sensor is for the computer, so thats why I wasnt sure what the deal with ours is. I'll pull it out too.