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500 ci caddy in a custom pickup
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13 Posts
Discussion Starter #1
Okay, although there was some trial and error, I'm not a complete idiot...I did some research, perused the forums for applicable threads....have learned a lot....of information and lessons!

Now, I need to get some results. Of course, when working with 35+ year old equipment....well, the method, and in fact, the results themselves, vary.

Here is where I am. I have essentially what used to be a 71 eldo (tho it is no longer the same sled. The 500 has been reincarnated in my early 90s Chevy Truck).

The Qjet still goes dry after sitting (see my comments on Qjet drain down thread). However, my primary concern is the choke.

My Qjet has a manual, divorced choke. It does not work properly (maybe at all)...

So should I:

replace it with another manual divorced choke (anyone have suggestions on where to find one)??

replace it with an electric upgrade (what issues will I be getting myself into with this, if it is even possible)??
 

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500 ci caddy in a custom pickup
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13 Posts
Discussion Starter #2
First, this is my first file attachment (fingers crossed)....

I hope that what you will find here is the choke stat on my 500.

Then, I hope someone out there has one, knows where I can find one, or has a viable solution to my choke issues.

I found a choke pull and have ordered it in an effort to be certain it is not either to blame or complicit!

Also, anyone want to go on record as to whether this one is original?
How about if I need to get a perfect match on the coil?
Anyone think that the intake could be to blame?

Anxiously awaiting help....thanks in advance.
 

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70 Deville 77 Fleet 78 Seville 92 Deville 03 Deville
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3,310 Posts
It looks fine to me. What is it not doing? Does the choke close when it's cold? Does the vacuum choke pull off pull in when the car starts?
 

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500 ci caddy in a custom pickup
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13 Posts
Discussion Starter #4
the choke pull appeared operative when I rebuilt the carb (suck test!). the DAC cleanup nicely and seemed fine as well. the linkage was a bit ragged (one piece was off entirely and inside the carb before the rebuild). however, everything appeared to be in place and working. once the rebuild was completed, she ran great and started much better.

Now, I suspect that either the intake is clogged or the coil is not reacting as it should. There are times when it works fine (mainly when it is warmer!). Other times not so much. Sometimes it does not reset (close when the accelerator is depressed)...it remains either open or at the startup setting (slightly open)....other times it does not open once it has warmed up.

I had a good example of this the other day. I went out on a cool morning and got her fired and allowed her to warm up for about ten minutes. All seemed fine. I put her in gear a coasted down the drive and onto the road. When I gave her the gas she seemed to hesitate and (for lack of a better term) bog. She died at the stop sign a couple of hundred yards down the road and would not restart.

When I popped the hood and removed the air cleaner cover...to my surprise, the choke flap was closed. I opened it manually, there seemed to be more tension on it than normal. I tried repeating the above process (resetting the choke and starting) to no avail...the flap remained closed. I stuck a pencil (hey, you do what you gotta do, work with what you got, etc.) in the carb to hold open the flap. She started and I drove her back home (and switched vehicles to go to work!).

It has been much warmer lately and has been starting and running fine. I have been busy at work and have not had a chance to run through a DAC adjustment to confirm at each step that everything is working. Hence, I am not certain if the choke pull, or the coil, or both...are to blame.

I found and ordered a new choke pull. I think I found a guy who has a DAC (THANKS DAVE). Hey, it's only time and money...what else do guys like us have to do?... :alchi:....
 

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70 Deville 77 Fleet 78 Seville 92 Deville 03 Deville
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3,310 Posts
If the choke was closed after running then either the choke pull is dead or misadjusted. I usually carry a clothspin in my toolbox to get me home in case my choke ever acts up like that. There is usually a precise adjustment for the choke opening but I usually eyeball it around 1/4-3/8 inch and fine tune from there. The choke linkage should all move freely with no binding too.
 

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90.5 Allante, 02 Deville, 13 ATS 2.0t
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119 Posts
The best source of Q-jet information that I have seen is on a site called Digitalcorvettes.com - Quadrajet info by Lars. It is very complete and has some great and complete info on how to set up an electric choke. I have this site maked as a favorite and I go there all the time. To be happy with a Caddy 500 you need to be a Qjet Wizard. when you get them right they are great.
 

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500 ci caddy in a custom pickup
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13 Posts
Discussion Starter #7
I like the clothespin suggestion Al and agree about the Qjet info on the vette site Blue. In fact, that is where I first came across the choke diagnostics - my weekend plan btw!

the linkage seems fine, though I have found few good pics of everything hooked up correctly. so maybe something there is an issue...

I find the Qjet wizard statement as somewhat ironic, however. It seems that all of the "wizards" have a different diagnosis and solution...seems more like there are no wizards...it is more like the willingness to tinker til you get the desired results...

I definitely know a lot more now...but seem to find even more possible problems and solutions the more I know...but I suppose that is why we love this stuff!

Thanks guys for all the help...I'll post more results after the weekend tinkering.

note: she fired fine and ran great to and from work today.
 

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'85 Fleetwood FWD
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728 Posts
Is it possible that the loop in the end of the climatic spring isn't over the tang on the choke link? If the tang was missed with the loop in the spring when assembling the choke housing, it would work in one direction and not the other.
Just an idea.....

(hope we are thinking about the same type choke:bigroll:)

The specs that come with rebuild kits are usually OK , for setting choke pull-off ,un-loader etc. Sometimes the link rods have to be bent/tweeked etc.
 

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500 ci caddy in a custom pickup
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13 Posts
Discussion Starter #9
I love your thinking in print Bill! I think you may be onto something with the linkage. Since one piece was in the carb at rebuilt there has to be some issue that allowed it to come loose.

It is my plan to run step by step through the choke diagnostic to one by one reduce the variables. I suspect that I will find that everything is working...sort of...hence it may be something like a linkage with a bit too much play (since is works part of the time).

Again, she fired and ran great this morning...and the temp read 37 degrees! If I had a major problem...well I would have driven the jeep today!

Since I hope to have a new DAC on the way, i will inspect it thoroughly to see if the coil is positioned properly...that is also a good suggestion Bill.

I will let you all know the results.
 
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