I pulled the Q off of my LeSabre 400 today to change the accelerator pump, and what I noticed is that my secondaries aren't opening... and not only are they not opening, they are locked shut! There is a little lever in the way, preventing them from opening, although the little lever isn't attached to anything to make it open/ close... so the secondaries stay shut at all time... although there is a little hole underneath it with nothing in it... I'm baffled... did someone previously disable it or what? I took some pics, so hopefully tomorrow I will post them up. I've looked in several repair books, including a Rochester book and the 1968 Buick shop manual, but I am having no luck... I hope someone can help me out here... Thanks in advance! :TU:
Yep, the older cars lock out the secondary air valves based on choke position. Don't confuse the air valves at the top of the carb with the actual throttle plates underneath which are a matter of mechanical linkage. And don't expect the air valves to open while watching them, wingng the throttle from under the hood...they need a strong engine load to get the air flow necessary to get them wide open which you probably can't do in the garage without getting the rpms pretty high. If they're not opening under wide open throttle driving, let us know. Devon
It could be that the choke lockout linkage was removed by someone not knowing better. I haven't looked at a Qjet in a while, to see what the linkage should look like. But it could be that someone removed it - thus the empty hole?
lock out It came from buick that way. Keeps the secondaries locked out untill the engine is warmed up. Keeps the engine from having 'cold bog'. Other wise, if the engine isnt warmed up and the secondaries are poped open the engine will fall on its face instead of accellarating.
yeah, trust me, I done a lot of reading last night on the secondary lockout lever. But see, mine isn't attached to anything... It just kinda dangles there, and keeps the air valve closed. WOT won't open it because there is no linkage or anything attached to it... I'm really thinking that it was disabled by someone before I got the car. I will post some pics up when I get a chance. My little boy is sick in the hospital, so thats where I've been all night and I really don't have the energy to upload a bunch of pics via dialup right now... Do any of you guys have a Q on your car that you can look and see what the lever is attached to?
There are hundreds of different Q-Jet carburetors; and the lockout is not actuated in the same manner on them all. For the carbs from 1965 to 1974 there are at least 3 different types of secondary lockouts (as we don't work on the newer ones, don't know about them). What is the identification number of your Q-Jet? Jon.
Someone may have removed part of the linkage in an attempt to improve MPG's by running off the primary side only o No: Steel welding rod(tig),makes for good linkage material.
Most Buick qjets have the lockout on the lower passenger side attached to all the choke/fast idle linkage. Take it off and throw it in a box. Just don't beat on it cold. Everyone knows this anyway.
7028244 is the number on the carb. oh, and correctiion copperhead.... now everyone knows this! :TU: btw: thanks everyone for the fast responses.
Most of those "boot-shaped" secondary lockouts aren't directly hooked to any linkages. When the choke opens all the way, the weighted fast idle cam (towards the front of the choke assy) has a tang on the backside that's supposed to hit the top/front of the lockout and move it out of the way. As long as you remember not to floor it until the engine is warm, you can leave the lockout off without any problem.
That style is 70-up. The 68 carb has a little lever at the top back passenger side of the choke tower that locks out the secondary butterflies. If I recall correctly, when the choke opens the choke rod pushes it up and off the secondary butterflies. Sounds like the choke rod may be missing on the carb in question.
Here's how it's supposed to work: Choke closed. The front half of the lever is hanging down, letting the back half of the lever swing back over the secondary butterfly, holding it closed
Choke open The thermostatic coil in the intake manifold warms up and pulls down on the rod that is attached to the external part of the choke. The shaft goes into the carb and connects to the internal lever that comes up to the actual choke butterfly. The front half of the lockout lever is raised by the open choke butterfly, pulling the rear half of the lever forward off the secondary butterfly.
Something I did not see here is whether the choke is opening all of the way. If the chioke does not open all the way, the secondary air valves will not open. This will cause rich mixtures and a high idle if it doesn't open. This will occur whether the secondaries open or not. It is very easy to have issues with choke heating, especially if the heated air cleaner does not work properly. Just a word to the wise. If the choke linkage can be pushed into the open position and free the air valves, it is a choke heating issue. Ray
I say remove the choke assembly entirely. I get around just fine with out it. Just feather the throttle till it warms up and your on your way. I've lived in PA my entire life and I've driven carburated cars year round this way and I've never had a problem. However the colder it gets the more it wants to fight you, but the convenience of not having to deal with a tempormental choke is worth it.
o No: - If your choke and choke pull-off is working correctly it will have a flawless cold start with zero drive ability issues during it's warm up to normal operating temperatures, the way it was designed to be. - Without a choke you have to keep feeding it fuel via the accelerator pump due to an extremely lean condition on a cold engine, keep it running, falling on it's face, all while wasting fuel. A properly working cold start system is a convenience, not the other way around.
