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1967 Cadillac Quadrajet choke won't close - very difficult to start

Started by Scot Minesinger, January 14, 2014, 10:51:27 AM

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Scot Minesinger

Working a 1967 DeVille w/429 and first Quadrajet carb.  The choke will not close.  The butterfly damper stays open and shuts partially allowing about 90% air flow and the car is impossible to start.  It is not the bi-metallic choke, as you cannot manually close the damper either.  It is not the 1/8" round stock linkage either.  It is being stopped by something.

Otherwise car runs great when warmed up.
Fairfax Station, VA  22039 (Washington DC Sub)
1970 Cadillac DeVille Convertible
1970 Cadillac Sedan DeVille
1970 four door Convertible w/Cadillac Warranty

Jon S

"Sounds like" the air horn is slightly warped as happens from over-tightening the air cleaner nut.  You may have to gently file the inside surface of the air horn (disassembled) as you move the choke plate back and forth.  It should be relatively easy to spot the high spot.

Jon
Jon

1958 Cadillac Sedan De Ville
1973 Lincoln Continental Coupe
1981 Corvette
2004 Mustang GT

"Cadillac Kid" Greg Surfas 15364

Scott,
If you are saying that with the rod from the choke stove disconnected you cannot close the choke then it sounds like someone has either put the carb together wrong or there is an issue with the secondary air valve lock-out.
Greg Surfas
Cadillac Kid-Greg Surfas
Director Modified Chapter CLC
CLC #15364
66 Coupe deVille (now gone to the UK)
72 Eldo Cpe  (now cruising the sands in Quatar)
73 Coupe deVille
75 Coupe deElegance
76 Coupe deVille
79 Coupe de ville with "Paris" (pick up) option and 472 motor
514 inch motor now in '73-

Gene Beaird

Scott, can you post some pictures?  I'm betting Greg is right, and the lower end of the linkage is disconnected.  It's also possible that someone completely disassembled the carburetor down to and including taking the butterflys off the mounting rods.  If that happened, the choke butterfly could be misaligned, preventing it from freely-rotating in the choke air horn.  That's fairly easy to fix, but you'll want to add a touch of Thread Locker to the butterfly screws to prevent them from falling out, and down into the engine.  You'll want to make certain this is a problem before moving those screws.

The choke butterfly linkage should connect to an arm down in the passenger side of the carburetor.  When you put the carburetor together, you kind of have to go 'fishing' for the end of that arm to hook the lower-end of that linkage into.  It's not difficult, but sometimes not obvious.  Failing to get that linkage hooked into the arm, the end will jamb against the top of that arm and keep the butterfly from moving much.  To test this configuration, you should be able to move the linkage around, forward and backward in the slot in the carburetor.  I should feel attached to something down in the carburetor.  If this end is loose, then that's where your problem is. 

Gene Beaird,
1968 Calais
1979 Seville
Pearland, Texas
CLC Member No. 29873

Jon S

Since Scott stated "It is not the bi-metallic choke, as you cannot manually close the damper either.  It is not the 1/8" round stock linkage either.  It is being stopped by something," I believe you guys are over-analyzing it and it is indeed simply a warped Air horn.  Scott - Please let us know what you find.

Jon
Jon

1958 Cadillac Sedan De Ville
1973 Lincoln Continental Coupe
1981 Corvette
2004 Mustang GT

Scot Minesinger

This carburetor has been worked on by a few shops, so I'm leaning towards the put together wrong concept than something that would happen over time.  Plus I had the car in March 2013 and it worked fine (did not even think carb needed work), then the owner had the carb worked on August by another shop, and here we are with it not working now.  Here is a picture.
Fairfax Station, VA  22039 (Washington DC Sub)
1970 Cadillac DeVille Convertible
1970 Cadillac Sedan DeVille
1970 four door Convertible w/Cadillac Warranty

Jon S

Carburetor doesn't look like it has been re-built or cleaned for some time.  Linkages appear to be connected correctly.  I still would remove the air horn and check for binding.

Jon
Jon

1958 Cadillac Sedan De Ville
1973 Lincoln Continental Coupe
1981 Corvette
2004 Mustang GT

TJ Hopland

I too don't think it looks like its had a proper 'rebuild' very recently.   Lots of varnish ooze visible everywhere.  Its either been a while or the person(s) doing it have not done a good job or used good parts.    Its tricky these days to find someone that really knows what they are doing with these things. 

I have not dealt with one that old in a long time but the rod going up to the butterfly looks a little odd to me. 

If you were not quite grasping the part about 'fishing',  basically that crank arm weight sort of thing the choke thermostat rod connects to rides on a shaft that goes into the side of the carb.   Its either a D or flat shaft where it goes into that little area the butterfly rod drops into.   The fishing part comes in that the rod connects to a crank arm that has to fit properly on that shaft.   If you have the carb on the bench its not too bad because you can just tip the carb to get gravity helping you.  On the car that is not an option and can take some luck and persistence to get it on there correctly.   If that was not on correctly that would explain why its not working and the rod looks strange to me.

That weighted crank arm contraption is also what acts on another weight thing in there that gets you the fast idle.  If the throttle shafts are worn it can kinda mess up the whole fast idle and choke operation.  I don't think I had this happen on a Qjet but had a few 2bbls that had that issue.

The function of the vacuum actuator varied over the years to but often did get involved in the choke so that is another thing that cold be not working correctly and messing things up.   Stuff like this can especially be a problem if the people working don't really know that specific model and start trying to compensate for problems rather than fix them. 

Lifting the top or air horn off one of those is not for everyone.  There is a lot going on there.   Its not too bad if you know what to expect.  There is kinda an order you have to follow.   
StPaul/Mpls, MN USA

73 Eldo convert w/FiTech EFI
80 Eldo Diesel
90 CDV
And other assorted stuff I keep buying for some reason

Dan LeBlanc

Here's another thought.  Do you have enough pedal travel to acheive WOT?  My choke on the 61 will only partially set if I don't depress the pedal all the way to the floor and if I'm under the hood, I can only get good free movement of the choke butterfly to close at WOT.  Anything but, I only get partial movement.

Maybe this newer stuff is different.

PS:  Owners manual says to depress the accelerator pedal slowly to the floor once before starting, so I'm not losing my mind here.
Dan LeBlanc
1977 Lincoln Continental Town Car

Jon S

The Quadrajunk is really not that more complex than the 4GC or for that matter from my favorite AFB.  Once you've rebuilt a few carburetors, it becomes "old hat."  The Quadrajunk is very similar to the Motorcraft 4300.  From my experience I strongly believe there is air horn warpage or binding. 

The butterfly should snap closed with partial accelerator - the reason to depress it all the way to the floor is to provide a complete squirt from the accelerator pump to "prime" the carb for easy cold starting.

Jon
Jon

1958 Cadillac Sedan De Ville
1973 Lincoln Continental Coupe
1981 Corvette
2004 Mustang GT

"Cadillac Kid" Greg Surfas 15364

Scott,
I thought you said the choke was disconnected.  Disconnect the choke (stove) linkage from the carburetor and see if that makes a difference.
Greg Surfas
Cadillac Kid-Greg Surfas
Director Modified Chapter CLC
CLC #15364
66 Coupe deVille (now gone to the UK)
72 Eldo Cpe  (now cruising the sands in Quatar)
73 Coupe deVille
75 Coupe deElegance
76 Coupe deVille
79 Coupe de ville with "Paris" (pick up) option and 472 motor
514 inch motor now in '73-

Gene Beaird

Hmm, I'm thinking the linkage to the choke butterfly may be bent the wrong way.  It's hard to tell w/o physically-moving the butterfly in person, but that's what it looks to me.  I'm thinking it should be bent the way I've outlined in orange, but my 68 FSM is showing the arm on the 68 to be bent the way yours is, so I may be mistaken here.  I'll verify by physically checking our 68 this afternoon.

You can verify that the choke butterfly linkage is connected to the choke linkage by trying to move the part I have circled in orange up and down.  The linkage should move up and down in the opposite direction you are moving that counterweight.  If it doesn't move with the counterweight, it's not properly-connected.

Gene Beaird,
1968 Calais
1979 Seville
Pearland, Texas
CLC Member No. 29873

Scot Minesinger

This forum is great - thanks for the input, I'm on the road to recovery.  The 1/8" linkage was slightly bound and a little needle nose plier work and it was free.  The bi-metal strip in a coil that activates the damper on carb is not strong enough to move it, so I'm going to replace it.  It moves so easily, major bummer that the bi-metal temp spring coil can't do it.  I call it the choke thermostat but have heard so many other names, wanted to make sure it was described correctly.
Fairfax Station, VA  22039 (Washington DC Sub)
1970 Cadillac DeVille Convertible
1970 Cadillac Sedan DeVille
1970 four door Convertible w/Cadillac Warranty

Gene Beaird

Ahh, that's good news.  I really need to replace the choke coil on our 68, too.  I think I can get one through quadrajetparts.com, but haven't looked that deep into it yet.

Gene Beaird,
1968 Calais
1979 Seville
Pearland, Texas
CLC Member No. 29873

Scot Minesinger

Found an NOS choke on e-bay for a 1967 Cadillac and purchased it right away.  I really lucked out.  The only other ones I have found are used and most places want $100 for a good one.
Fairfax Station, VA  22039 (Washington DC Sub)
1970 Cadillac DeVille Convertible
1970 Cadillac Sedan DeVille
1970 four door Convertible w/Cadillac Warranty

Jon S

Jon

1958 Cadillac Sedan De Ville
1973 Lincoln Continental Coupe
1981 Corvette
2004 Mustang GT