choke rod length

[Gmc.guy]

A 3 foot length of 1/8" rod is cheap and I grab 1/8 external snap rings at the hardware store I am sure I seen it here but using a side cutter or dykes you can cut the groove after you bend it by putting them tight to the bottom and with light grip and spin the rod slowly with the other hand and check with the snap ring once in awhile for a nice fit. I usually make a rough one and then a nice one before it works out

[davepl]

Originally Posted by slowboy

thanks will try...just not sure what keeps the choke from staying on at first start...doesn't stay on but a few seconds then the choke plate seems to close back choking motor out

There should be a vacuum diaphragm called the "pull off". When cranking, the choke is totally closed when cold. As soon as the engine fires and makes vacuum, that little diaphragm pulls the choke open about 1/4" or so.

If that's malfunctioning or leaking maybe it's letting the choke close all the way again? Just a guess.

I second the Ruggles book, it's good.

[yuccales]

Originally Posted by slowboy

yuccales ... I can see from your picture that from end-to-end your rod is around 2-5/8" long...can you give me the length where rod goes through coil spring and the length of other end where clip goes on...thanks, Keith

I will take a measurement for you tomorrow. As others have said, Cliffs book on Q-Jets is a must have.

[yuccales]

Originally Posted by yuccales

I will take a measurement for you tomorrow. As others have said, Cliffs book on Q-Jets is a must have.

Hope you get it worked out.

[slowboy]

Originally Posted by yuccales

Hope you get it worked out.

Thanks for all of your extra effort, I very much appreciate it ! !
slowboy

[slowboy]

Originally Posted by davepl

There should be a vacuum diaphragm called the "pull off". When cranking, the choke is totally closed when cold. As soon as the engine fires and makes vacuum, that little diaphragm pulls the choke open about 1/4" or so.

If that's malfunctioning or leaking maybe it's letting the choke close all the way again? Just a guess.

I second the Ruggles book, it's good.

the choke seems to close fully when I first press pedal all of the way to the floor...it isn't fully closed until I do press pedal all the way to the floor...then I release gas pedal and crank...the choke does open some while truck starts...the engine runs for a few seconds, then the choke seems to close back some causing it to idle rough [like choking out]...
per my picture, can you tell me where/what this 'pull-off' is and where the vacuum lines should be connected? there's 2 ports on my carburetor that are capped off, one you can see and the other is off same small tube coming from carburetor directly beneath it [it's a sort of 't-fitting' coming out of carburetor there...I thought that it was the big round thing, but someone said that was for the secondary...
thanks so much davepl

[slikside]

Originally Posted by slowboy

the choke seems to close fully when I first press pedal all of the way to the floor...it isn't fully closed until I do press pedal all the way to the floor...then I release gas pedal and crank...the choke does open some while truck starts...the engine runs for a few seconds, then the choke seems to close back some causing it to idle rough [like choking out]...
per my picture, can you tell me where/what this 'pull-off' is and where the vacuum lines should be connected? there's 2 ports on my carburetor that are capped off, one you can see and the other is off same small tube coming from carburetor directly beneath it [it's a sort of 't-fitting' coming out of carburetor there...I thought that it was the big round thing, but someone said that was for the secondary...
thanks so much davepl

Your arrow is pointing to the port that draws the the fumes from the charcoal canister....for emissions.

As you describe it (choke slowly closing after start, and choking out idle), it doesn't sound like the choke pull-off is working...

When you are facing the front side of your carb, on the lower left side, just above the left idle mixture screw...there should be a port that comes down at an angle toward that little pot cannister on the left side of your carb. That would be the choke pull-off, and it should be connected to the port that I just described. It would only take about a 2" length of vacuum hose to connect them.

If you have a vaccum pump, pull some vacuum on that choke pull-off and see if it will hold it. If it doesn't, it's bad. Or, if it's not connected, then do so, and see if this helps. If it does, then the pull-off must be working, if not, it's probably bad.

[slikside]

In fact, as I look at the photo more closely, I think you can just see the port coming out of the carb body just above the choke pull-off cannister (that's the cannister just to the right of your port with the arrow pointing to it).

[geezer#99]

His choke pull off is working. You can see it in 3rd pic in post #5. THe link bar is pulled in. And the secondary damper link is moved ahead into run position.

[slikside]

One more thing...from the three photos you posted on the first page:

Photo three is what it should look like immediately after starting. It DOES appear that the choke pull off is working. You can see that the shaft coming out of it appears much shorter than in the other photos. The choke plate opening looks a little large for just after start, but you say this is only after being warmed up. And that choke plate should be verticle when it is fully warmed up so the engine can get the maximum amount of air.

So you have two separate adjustments to make:

One is to get the choke rod length such that when the engine is fully warmed up, the choke plate is wide open...vertical.

The other is to set the pull-off distance on the plate just right and have it stay there after engine start. (It's another rod bending adjustment).

Ruggles' book addresses all of it.

[slikside]

You're right geezer. Took me a while to type my last...

[slowboy]

Originally Posted by slikside

One more thing...from the three photos you posted on the first page:

Photo three is what it should look like immediately after starting. It DOES appear that the choke pull off is working. You can see that the shaft coming out of it appears much shorter than in the other photos. The choke plate opening looks a little large for just after start, but you say this is only after being warmed up. And that choke plate should be verticle when it is fully warmed up so the engine can get the maximum amount of air.

So you have two separate adjustments to make:

One is to get the choke rod length such that when the engine is fully warmed up, the choke plate is wide open...vertical.

The other is to set the pull-off distance on the plate just right and have it stay there after engine start. (It's another rod bending adjustment).

Ruggles' book addresses all of it.

Can you be a little more specific about how to adjust/set the pull-off distance on the plate just right and have it stay there after engine starts please?...thanks

[slikside]

I absolutely would if I had my book, but I'm out of town til the weekend. I will be happy to provide specifics then...anyone one else with a Ruggles book (or other good q-jet book) that can help before I can??

Generally though, that pull-off should open it up roughly 1/4" or so when activated. Use a drill bit, or something else that size to measure. Tweek the rod coming from the choke pull-off to achieve this opening and no more. If the pull-off is working, and it appears to be, then the only variable I can remember is that rod.

That's all I can give you right now from memory from about 5 years ago. Hope it helps.

[slowboy]

Originally Posted by slikside

I absolutely would if I had my book, but I'm out of town til the weekend. I will be happy to provide specifics then...anyone one else with a Ruggles book (or other good q-jet book) that can help before I can??

Generally though, that pull-off should open it up roughly 1/4" or so when activated. Use a drill bit, or something else that size to measure. Tweek the rod coming from the choke pull-off to achieve this opening and no more. If the pull-off is working, and it appears to be, then the only variable I can remember is that rod.

That's all I can give you right now from memory from about 5 years ago. Hope it helps.

is the rod with yellow arrow the rod that needs bending?...

[HO455]

Yes it is. The 45* bend by the pull off is where you bend it to adjust. The pull off is holding the choke open as it should. I believe the choke is not being opened enough as the engine starts, then starts to stumble and loses vacuum and the choke pull off spring closes the choke. If the choke was being held open too much the engine would try to recover as the choke closed. Since your carb seems to be missing the secondary lock out (or it is assembled wrong) I would double check to see that the fast idle cam is working correctly. My guess is that it isn't, as some Q-jets need the secondary lock out to be installed correctly for the fast idle to work. When you push the accelerator pedal to set the choke the fast idle cam should drop and hold the primary throttle plate open slightly. There is an adjustment for the fast idle speed. If this doesn't happen then the engine won't stay running after starting.

[geezer#99]

Originally Posted by slowboy

is the rod with yellow arrow the rod that needs bending?...

No it's not.
That's the secondary dampening rod.

[HO455]

Whoops! My bad you are correct. The 90* tab under that rod and next to the spot where it goes under the choke pull is the adjustment.

[geezer#99]

Nope, still wrong!!
The sorta 90 degree end on the top(by the rivet) is what adjusts how far open the choke blade is opened.
But he has other problems too. Without the secondary lock out tang in place the whole assembly sits crooked. The tang acts like a spacer to keep everything square and aligned properly.

[HO455]

2 strikes and I am out. Please explain the process of pulling that rod out and bending it for the correct adjustment along with how the lock out cam is installed.

[geezer#99]

THere's some nice color pics in here for how it gets assembled.
http://www.hotrodders.com/forum/roch...-190558-5.html
On the adjustment you just grip it with some pliers or visegrip and bend on the end that points towards the carb body. The end makes contact with the counterweighted arm.

[slowboy]

Originally Posted by geezer#99

THere's some nice color pics in here for how it gets assembled.
http://www.hotrodders.com/forum/roch...-190558-5.html
On the adjustment you just grip it with some pliers or visegrip and bend on the end that points towards the carb body. The end makes contact with the counterweighted arm.

I still have no clear idea of where adjustment is...will someone please show me where to adjust...maybe a picture with arrow pointing to where adjustment is made...PLEASE

[geezer#99]

..maybe a picture with arrow pointing to where adjustment is made...PLEASE[/QUOTE]

Luv too!! But way beyond my brain!!
In this link there's three pics. The last pic shows the arm.
The one that is a 90 degree angle with the funny shaped end. It pushes on the counterweighted lever that has a hole in it. That action opens your choke plate thru the linkage. You need to bend that end of the arm to make your choke open further or stay closed more.

http://www.corvetteforum.com/forums/...djustment.html

[slowboy]

Originally Posted by geezer#99

..maybe a picture with arrow pointing to where adjustment is made...PLEASE

Luv too!! But way beyond my brain!!
In this link there's three pics. The last pic shows the arm.
The one that is a 90 degree angle with the funny shaped end. It pushes on the counterweighted lever that has a hole in it. That action opens your choke plate thru the linkage. You need to bend that end of the arm to make your choke open further or stay closed more.

http://www.corvetteforum.com/forums/...djustment.html[/QUOTE]

ok, this rod?...and bend it where, blue arrow, yellow arrow, or green arrow?
or bend here, orange arrow?...

[geezer#99]

Orange arrow.
Bend it to the right and your choke plate opens further.
Bend it to the left and your choke plate is closed further.

You'll notice yours (orange) is bent less than the one in the other pic which is about 90 degrees.
You'll need to fine tune yours.
That arm pushes on the high idle cam. Two things happen. THe choke plate opens and the high idle drops down.

[slikside]

Well, I was wrong about "where" to find the adjustments (among other things!). Ruggles ' book IS great, but the adjustments are found in the instructions that came with his rebuild kit. I have attached the pertinent diagrams:

The first is a table showing (arrow) what the plate should be adjusted to with the pull-off activated depending on your carb model.

The second is the diagram showing you HOW to do it, and alas, which rod to bend! On this and the next photo, my handwritten measurements are for MY truck...although I believe your choke rod adjustment (last pic) should be the same as mine.

Reference the underlined title at the bottom of each diagram to be sure of which adjustment you are making.

EDIT: "Choke Rod Adjustment" is for initial setting when cold, after first press of the pedal...IIRC, you don't really have a problem with that, but I included it anyway...