Choke opener
11-23-2010, 08:19 AM
#1
Registered User
Thread Starter
Join Date: Nov 2010
Posts: 15
Likes: 0
Received 0 Likes
on
0 Posts
Choke opener
Trouble with my 86' 22R idling high. All vacuum lines are hooked up. Like fast idle when cold, but won't stop. Seems the choke opener is stuck. Any tips on replacing it? The Chiltion is no help. Thanks
11-23-2010, 08:24 AM
#2
First, pull the hose off of it with the motor warm and see if you are getting vacuum, my understanding is that you should be. Attach a lenght of hose and suck on it to see if it actuates the cold idle cam.
Here is some good reading.
Mine does not kick down either but the diaphragm works and holds vaccum. I am thinking my BMSV (I think thats the name) is to blame.
Here is some good reading.
Mine does not kick down either but the diaphragm works and holds vaccum. I am thinking my BMSV (I think thats the name) is to blame.
11-23-2010, 09:12 AM
#4
Registered User
Thread Starter
Join Date: Nov 2010
Posts: 15
Likes: 0
Received 0 Likes
on
0 Posts
Ok thanks for the prompt responses! So the choke opens and closes when I suck and blow on it, and the spring mechanism works well. I can get a volt meter, any suggestions on how to test that?
11-23-2010, 10:04 AM
#5
Registered User
Thread Starter
Join Date: Nov 2010
Posts: 15
Likes: 0
Received 0 Likes
on
0 Posts
I don't see any wires, just a vacuum diaphragm connected with a single bolt. All hoses are connected, and none have leaks, but should I get vacuum pressure while it's idling? Or only when I hit the gas? I'm not getting any pressure when at idle.
11-23-2010, 10:11 AM
#6
Registered User
lol We are working on an 86 and not something like a 79-80 that has a water choke right?
There is 3 going to the carb, follow the one that goes to the choke coil. Opposite side of the carb then the opener. 1 wire is for the fuel cut-off, one wire is for the vent solenoid, one wire is for the choke.
Any time the key is on the choke coil is supposed to have 12V to it. take the positive side of the volt meter hook it to the connector, place the other side on the negative battery terminal. you should see roughly 12V.
upper left corner. the red wire goes to the choke coil. If there is no wires, then that would be part of the problem as the P.O. probably removed them for some stupid reason.
There is 3 going to the carb, follow the one that goes to the choke coil. Opposite side of the carb then the opener. 1 wire is for the fuel cut-off, one wire is for the vent solenoid, one wire is for the choke.
Any time the key is on the choke coil is supposed to have 12V to it. take the positive side of the volt meter hook it to the connector, place the other side on the negative battery terminal. you should see roughly 12V.
upper left corner. the red wire goes to the choke coil. If there is no wires, then that would be part of the problem as the P.O. probably removed them for some stupid reason.
Last edited by xxxtreme22r; 11-23-2010 at 10:16 AM.
11-23-2010, 11:23 AM
#7
I am pretty sure he is talking about the Choke Opener Diaphragm. The Choke Coil initially closes the choke and cracks the throttle plate when the choke coil is cold. Then as the motor starts and "high idles" for a bit, it warms the BMSV which slowly switches vacuum over to the Choke Opener Diaphragm. As more vacuum is allowed to pass with the warming motor the fast idle cam slowly steps the idle down to the stock 700-750rpm.
Thats how I understand it anyway.
This is a pretty good read.
*
*
*
Thats how I understand it anyway.
This is a pretty good read.
*
*
*
Last edited by Shifty762; 11-23-2010 at 11:25 AM.
The following users liked this post:
gullyrat (10-21-2023)
Trending Topics
11-23-2010, 12:36 PM
#8
Registered User
the BVSV is either open or shut there is no in between.
there is a spring inside the choke coil which keeps tension on the throttle to keep it on the fast idle cam. as this heats up tension is released, if enough tension is released the throttle will come off the fast idle cam. If there is no 12v to this coil it will take much longer to heat up if at all and the engine will stay on the fast idle cam.
the choke breaker and choke opener diaphragm are not needed for the carb to operate properly.
This is assuming the choke coil has released enough tension on the throttle.
Go out to your truck when it's cold, remove the connector from the choke coil and you will see what I mean.
there is a spring inside the choke coil which keeps tension on the throttle to keep it on the fast idle cam. as this heats up tension is released, if enough tension is released the throttle will come off the fast idle cam. If there is no 12v to this coil it will take much longer to heat up if at all and the engine will stay on the fast idle cam.
the choke breaker and choke opener diaphragm are not needed for the carb to operate properly.
Choke Breaker Diaphragm
This diaphragm barely opens the passenger side choke plate shortly after the engine starts. This is to lean out the mixture a little as it does not need to be as rich as when the engine was starting. The engine will run fine without this diaphragm working.
This diaphragm barely opens the passenger side choke plate shortly after the engine starts. This is to lean out the mixture a little as it does not need to be as rich as when the engine was starting. The engine will run fine without this diaphragm working.
Choke Opener Diaphragm
This diaphragm slowly disengages the fast idle cam which in turn opens the passenger side choke plate. The choke opener, like the AAP, is also controlled by vacum from the BVSV. This diaphragm is not necessary as you can acomplish the same exact thing by punching the gas pedal when you wish to disengaged the fast idle cam.
This diaphragm slowly disengages the fast idle cam which in turn opens the passenger side choke plate. The choke opener, like the AAP, is also controlled by vacum from the BVSV. This diaphragm is not necessary as you can acomplish the same exact thing by punching the gas pedal when you wish to disengaged the fast idle cam.
Go out to your truck when it's cold, remove the connector from the choke coil and you will see what I mean.
Last edited by xxxtreme22r; 11-23-2010 at 12:38 PM.
11-23-2010, 12:43 PM
#9
Registered User
Thread Starter
Join Date: Nov 2010
Posts: 15
Likes: 0
Received 0 Likes
on
0 Posts
Ok, thanks guys all of this is making sense. My tool box slid out of my bed, just don't want to buy a new volt meter, but I need to invest anyway. I'm still not sure how it all fits together, but I'll catch on.
11-23-2010, 04:04 PM
#14
Registered User
Thread Starter
Join Date: Nov 2010
Posts: 15
Likes: 0
Received 0 Likes
on
0 Posts
Choke Thermostat?
I think I'm getting somewhere. The cold idle won't shut down anymore, and I was referred to try the choke voltage. At idle it's only at .71 volts. Am I looking at a thermostat issue or wiring issue.
11-23-2010, 04:33 PM
#19
Registered User
Thread Starter
Join Date: Nov 2010
Posts: 15
Likes: 0
Received 0 Likes
on
0 Posts
I don't understand what you are saying. I am not suggesting that a bad coil would make for no electricity in a wire, that's backwards. How would you get that?
Ok sorry about the new thread, just trying to get some other ideas, but now I understand the site. I was testing the wire that you suggested and got .71 volts. From there I am guessing I have a bad choke thermostat, and I will look at that.
Ok sorry about the new thread, just trying to get some other ideas, but now I understand the site. I was testing the wire that you suggested and got .71 volts. From there I am guessing I have a bad choke thermostat, and I will look at that.
11-23-2010, 04:37 PM
#20
Registered User
you had said no voltage and that the coil must be bad twice I might add. Coil IS NOT bad, it just will not work if there is no voltage to it. Now you got to figure out why your not getting voltage there. It's NOT because the choke coil is bad.
Maybe your not understanding that a choke thermostat and choke coil is the same thing?
I would first start by checking the fuse in the fuse box under the hood. I cannot remember off hand which one it is. If you find the fuse and it is good, then I would check to make 100% sure the wire connectors in the green or grey plug are joining correctly inside that plug.
Maybe your not understanding that a choke thermostat and choke coil is the same thing?
I would first start by checking the fuse in the fuse box under the hood. I cannot remember off hand which one it is. If you find the fuse and it is good, then I would check to make 100% sure the wire connectors in the green or grey plug are joining correctly inside that plug.
Last edited by xxxtreme22r; 11-23-2010 at 04:44 PM.
