question on choke system

[rddaves54]

Need to understand this choke system. When it is cold should the choke be pulling down on the rod or pushing up?


I had a divorce choke and when it got warm it pulled down that seemed to be closing the plate. I put on an electric choke and it is pulling down also when it gets warm. Does the plate need to open all the way when the engine is hot and running if so why would the choke be pulling down when hot??

Both chokes are working or pulling when hot but they seem to pulling the plate closed and not pushing it open.

I need help!

[geezer#99]

Take a pic of the choke side of the carb. Much easier for us to help if we can see it.

[rddaves54]

Here is a picture of the electric choke I put on this morning when it warms up it is pulling down on rod wanting to keep plate from opening.

Everything is connected according to the diagrams in my books.

[68gmsee]

I think what geezer wanted was a pic of the linkage and choke asm. If you can, take another pic but make sure it includes the top.

Here's an example:

[mclairmo]

Choke assembly must open the choke plate when warm. Maybe the spring inside is backwards? Or, maybe the whole assembly is 180 degrees out of whack? You need to get it positioned so that when it gets warms that rod goes up and opens the choke plate.

[rddaves54]

Here are some more pictures.

I agree that the rod should push up and open plate but when it gets warm as the old divorced choke also did it pulls down. The electric choke only goes on as you see it, so I do not know how to reverse the spring or choke.

I sure would like to get this corrected??

[geezer#99]

Perplexing!!! Couple questions come to mind. Does the vacuum pot pull in when you start it. Can the black canister be rotated. I'd be interested to see inside the canister and the back side where the rod attaches. The coil inside should be reversible.
Possibly a pic of choke position and linkage when warmed up and running would help too.

[68gmsee]

There was a discussion about this some time ago. Don't remember if it was last year or year before but the post was about the coil spring being backwards. I posted a pic of my original divorced choke that I used to have on my old carb and I'm reposting again. If you still have yours you can compare.

[geezer#99]

Good pic of your divorced choke coil. I had one installed backwards once. I don't have carbs handy to look at and can't find my rochester quadrajet book so the pics help alot. Memory not as good as it used to be. LOL!! Thanks for the reference pics 68gmsee.

[rddaves54]

I have markings on the outside of the electric cholke case but can only move it so far each way according to the marks on the plate. I don't know what would happen if I took the cover all the way off.

Has anyone taken a electric choke apart and turned the spring around? What does one look like inside?

I did nto want to take it apart and mess it all up.

[geezer#99]

No need to pull it apart yet. If it's not a prob could you take a pic of it right after you start it up. Easier for us to cure your problem with another pic. And maybe one once it's warmed up too. Thanks. We'll get to the bottom of this yet!!!

[68gmsee]

I've taken the cover off the stock ones. Depending on how it's made, it probably has a protrusion that moves the spring in one direction or the other.

Here's another pic.

http://arrc.epnet.com/autoapp/8973/c.../89735g35L.gif

[rddaves54]

Ok here are the pictures I will try to put them in order. First one is cold, second is with choke set (?) third is running cold, fourth is running warm and the rod is pulling down keeping plate from opening.

It took about 1-2 minutes for choke to engage but it is pulling down and not pushing up. One close up of rod pulling down in next post.

I may have to put pictures in two posts

[rddaves54]

close up of rod.

[mclairmo]

In the last 3 pics of your 5 pic series the choke plate is open, not all the way, but still mostly open, which is correct if the engine is warm. You should adjust it so that it is all the way open when at operating temp. Your "close up of rod" pic shows that the linkage connection is not direct and that as the rod you show goes down, it must actuate a linkage that opens the choke plate, not closing it. I don't think you have nearly as big a problem as you think. Just adjust as I have advised and all should be fine.

[geezer#99]

Thanks for the pics. In the last pic the bent rod (just to the right of your choke rod) with the orange paint dab on it needs to be removed and made shorter by bending it right at the paint dab point. When its shorter the vacuum pot will pull the choke rod up and it should kick off high idle. You'll have to experiment a bit. Bend a little at a time. Shouldn't take much. I've used 2 pairs of pliers to bend one before. Go easy.

[geezer#99]

Originally Posted by mclairmo

In the last 3 pics of your 5 pic series the choke plate is open, not all the way, but still mostly open, which is correct if the engine is warm. You should adjust it so that it is all the way open when at operating temp. Your "close up of rod" pic shows that the linkage connection is not direct and that as the rod you show goes down, it must actuate a linkage that opens the choke plate, not closing it. I don't think you have nearly as big a problem as you think. Just adjust as I have advised and all should be fine.

I beg to differ. The choke plate should be almost verticle. The choke rod is holding the choke closed slightly via the linkage because the choke pull off(the vacuum pot) is not pulling the choke rod via the linkage to the upward position and keeping the choke plate slightly closed and staying on the high idle cam. The lever sticking out above and to the left of the pot(with the hole in it) is a weighted arm which the high idle cam sits on. In all the pics it is visible. Whether hot or cold. In normal operation you shouldn't see it from the side. Bending the linkage I mentioned in my other post should cure this. JMHO

[mclairmo]

I realize that the choke plate needs to be vertical, which is why I said "the choke plate is open, not all the way." You don't need to beg to differ. I think we are on the same page already. The OP implied that the choke plate was all the way closed even after warm up, which is not entirely true from the pics. He said it was "pulling the plate closed" when hot. Clearly, it is partially open on warm up, just not 100% open.

[rddaves54]

Cliff Ruggles says in “How to rebuild and modify Rochester Quadrajey Carburetors” this about chokes. “The choke flap is controlled by a thermostatic coil that is affected by temperature differences. Cold temperatures cause the coil to wind in a direction that applies the choke, and it retracts and opens the choke as the metal coil is warmed.”

That is what I was saying about the electric choke that when it gets warm it was pulling down and not up which kept the flap from opening all the way. I do not see how bending the rod suggested would help reverse the choke from pulling down on the flap. I do not know how to get the electric choke to reverse itself it that is even possible.

So I am back where I started the electric choke is not working as Ruggles says it should work.

[mclairmo]

I would take out the spring located inside the black plastic choke housing and reverse it. I believe that would enable the rod to move in the opposite direction.

[geezer#99]

So don't bend it to shorten it. When you're warm and running pull on the rod I mentioned which will pull the straight choke rod upwards. Tap the throttle and it should drop off the high idle cam. That lever closer to the carb body with the hole in it controls the high idle and the choke butterfly. If that works you know you need to make it shorter.
By looking at your pics I'd bet it always runs on the choke high idle cam.

[rddaves54]

Thanks for all the help.

I wanted to update everyone.

I found an old new stock choke on e-bay and when I got back from vacation I put it on and it is working great. Truck starts great and runs fine.

I learned quite a bit and thanks for all the great information and help.

[68gmsee]

Great that you got it fixed...


Does that mean we won't find out what the problem was?

[rddaves54]

"Does that mean we won't find out what the problem was?"

I think it was incorrerct choke and now the correct one is on it corrected the problem????

As far as I can tell the new choke now holds the tension on the choke plate to keep it closed until the choke pull off opens it slightly until it gets to the warm running temperature.

It is not running on the choke high idle cam as it seemed to be before.

I believe that was the problem.

[grs]

Maybe this was mentioned. Unscrew the screws that hold the choke housing on the carb. Do this with the choke hot. Unscrew them just enough so you can turn the choke. Turn the choke housing in the direction that will open the butterfly choke valve plates. See if this will open it up more. Then re tighten the screws.