Well I have rebuilt my CC-Qjet and all is well in idle land. But I get pretty bad boggin just beyond idle up untill secondaries then its really powerfull with no issues. My question is how many turns out it correct for the lean stop screw? My factory 82 manual says 3 1/8 but after doing a search most people say 5 1/2. I am getting a lean code 44 from my computer but now sure if this is my problem. I am also having a very hard time finding the correct tools and guages to make adjustments through the air horn holes. Autozone, Kragen, Pepboys, Napa, And even street rod shops look at me like I want some part for a Model-T and tell me how they have not worked on a quadrajet for 10 years..

I even took it in to several mechanics for advice or for them to fix it and they say how obsolete it is and how much better fuel injection is.. Im like I know fuel injection is great but thats not what I have on this car. ohh the politics of auto repair..lol

I know its in the carb as it would not idle before but drove just fine. Also all vac lines are new and hooked up correctly. Oh and the MCS does click and the TPS is good.


Anywho any help would be great.

 

A smaller number of turns will tend to make it run leaner, because the larger portion of the rods will be down in the jets more of the time.

5½ turns is a good starting spot, usually.

Make sure you have 2 good O-rings installed on the idle air bleed assembly (in the air horn). If they're bad or came off during install or otherwise aren't sealed, it will cause a lean condition in almost any high vacuum / low RPM operation. Use a little spray silicone on them for asembly lube.

The rich stop should be at around 3 turns.

Make sure you know which one is which.... the lean stop is the screw that mashes the MCS down against its screw, the rich stop is the one about the size of a dime in the air horn, above the MCS.

You can make yourself a tool fairly easily; all you need is a rod about 3/16" diameter, with a slot about 1/16" wide cut in the end of it about 1/8" deep. Put a handle on it to make it easier to use. If you leave those stupid plugs out of the top of the carb at least until you get it dialed in, you can get at everything with the carb on the car and the engine running.

Check your MCS duty cycle at the green connector by the blower motor, with a dwell meter. It should be very responsive to the IAB; much less so to the lean & rich stops, but it should respond somewhat. The duty cycle should be near 50% (30° on the 6-cyl scale), between 35% & 65% would be OK, at idle, when fully warmed up and in closed loop.

 

Ok on the rich stop do i start all the way clockwise and back it out like the lean stop? Or start all the way counter clockwise and screw it down?

 

If you're looking at it from ouside the carb, full CCW (to where it bottoms out against the underside of the air horn, then 3 turns CW from there.

 

OK OK I'm kinda hyper right now cuz my car actually runs right!.. Just made a tool like you sugested. I lopped off the end of a small screw driver.. Then made a slit with my grinder.. I did 5 and 1/2 turns out on the lean mixture and 3 on the rich micture.. Still need to get a dwell meter for the IAB screw but it is currently at 5 and 1/4 turns out from the bottom i need to check this but does that sound right? Boy Oh Boy does this thing haul.

Thanks so much for all your help.. I know these settings are close.. to check them Ill need a float guage right?

If I run into any trouble with the IAB I will post it here.

Thanks Again
-Michael

P.S. I am going to go back to the shop that said I needed another full rebuild and that the computer did everything on these carbs and you cant adjust anything. Looks like we proved them wrong..

 

Great! So much for the professionals, eh??

The computer actually has only a very limited range of "command" over the carb's behavior. If the carb isn't set up right, the ECM's capabilities won't be anywhere near enough to bring it back in.

Once you get the lean & ricj stops right, you'll find that the car's idle and cruise is VERY responsive to the setting of the IAB. Definitely try tweeking that a little at a time until you get it to run the best.

Frankly I'd suggest leaving the float setting alone; you have to take the carb all apart to dink with it anyway, and risk disturbing something else. If it runs right with it where it is, just leave it there.

This is why people hate those carbs. Nobody but a few of us carb geeks can ever get them to work right. It's a lost art. When they're right, they're damn good; but when they're not, they're .... not.

 

Ya I totally agree.. Now that its right its great but before It made me want to go to tbi or something but I want the stock 82 stuff. I think it is a lost art. Mechanics seem to have either forgot how to work on them or never really knew in the first place.. And you cant find any knowledgeable carb people just walking into shops.
I sure am glad you guys know what your doing.

Well thanks again this has been an ongoing project car since sept 2002 and this is the first time It feels like a true muscle car.
Now I can enjoy my new engine.



-Michael

 

Did a search and found this post. My car is spewing massive amounts of black smoke out the tailpipe. Do you think its related to the lean and rich stop settings. Also my secondaries dont open at all. Is the lean stop screw the one you are supposed to set with the special gauge that reads like 1.403 or something like that? Quads are a lost art but it sounds like you guys know what youre doing. ANy help left?

 

Spewing black smoke usually means that the needle & seat has lost control of the fuel feed. It could also be that the float is no longer a float, but rather has become a sink. In either case, it's got to come off and be repaired. It's beyond anything that can be "adjusted" out.

First order of business would be a rebuild. Get a carb kit, a float, a choke pull-off, and a throttle position sensor. Tear the carb down; count how many turns the lean stop is from the bottom (screw it all the way down from wherever it is until it bottoms, and write it down) and how many turns the lean stop is from the top, and how many turns from the bottom the IAB is. Soak the carb in lacquer thinner overnight. When it comes out, turn the fuel bowl upside down; right under the primary jets, you will observe 2 blobs (technical term) of casting material, each of which has 2 small plugs spun into it; wire brush the hell out of all that until it's shiny and rough, clean it sterile with lacquer thinner, epoxy over all 4 plugs with JB Weld, and bake it in the oven at the lowest "warm" setting for a couple of hours.

When you're ready to reassemble it, come back for more.

 

Yes here in lies the problem. I have already rebuilt the carb lol. ANd have replaced everything I could possibly think of. I soaked the carb in chem dip for about 3 days then pulled it out and cleaned it up. Bought a rebuild kit and slapped it together put it on the car and it runs pukey. The float is new, the vaccum break is new, tested the tps works fine, and adjusted the choke pull off. (Thats the green one right?) I checked the float with a small ruler and pushed it down and it pushed back up. I suppose I can check again. After reading some posts i think ill check all my vaccuum lines again too. Could i have screwed the rebuild somehow?

 

It's possible....

Did the needle valve screw down into the fuel bowl properly? Use a gasket under it? You might have fuel leaking around it.

Something to do with the needle valve is by far the most likely thing that will cause that.

Did you epoxy the plugs? It's possible that if they leak REALLY BAD, they could let enough fuel through to do that. Remember, there's fuel above them, and vacuum below; the fuel is trying to drip, and the motor is trying to suck it in.

 

Yea i re epoxied the well plugs and that shouldnt be the problem. Which part is the needle valve? That doesnt seem to ring a bell maybe I missed that. Gasket under it... uhh oh?

 

Yea I did that one as well. Thats the one you need the larger screwdriver for right. maybe i didnt torque it enough. That little hanger the seat rides on is new as well. I'll pull it apart and double check it today.

 

Another possibility, that will cause the needle to hang up in the seat, is having the little clip that holds the needle to the float, installed wrong..... it MUST NOT go through the holes in the float arm. It needs to hang on the arm from the inside, i.e. toward the float itself; with the clip just around the edge of the bar across the float, such it's directly under the little round tab, free to move.

 

Ok thanks for all your help! Im going to try that today and see what happens. Now that its light outside i can see where the exhaust is leaving large black sooty deposits on the ground. Not to cool!

 

Adding to what RB said, have you also made sure your choke is opening fully? That would explain both the over-rich condition AND the secondaries not opening. Being rich from the choke not opening is pretty obvious, but the choke linkage on a stock Qjet also controls a secondary throttle "lockout arm" that prevents the secondary throttles from opening any time the choke is on (even slightly).

Choke problems are among the most common issues with Qjets. Bad adjustment, incorrect assembly (binding in the linkage), a choke element that is not being fed proper voltage (the 12V+ plug on the side of it) or a choke element that is just plain dead are the usual suspects.

 

I might add, on the choke thing, using a gasket between the choke cover (the part with the thermostat spring) and the housing, will also cause the choke to remain closed by never heating. The stat must be grounded to the housing.

And, an alternator that doesn't charge, will also cause the choke not to heat; there's a relay that's operated by the alt when it charges, such that if the alt is not charging, the choke doesn't get its juice. That's so that the choke doesn't get heated if you just turn the key on with the engine not running.

 

Yea the choke is opening all the way. Once the car warms up the primary blades are at 90 degrees to the carb. I thought about the secondary lockout lever before so I modified it...I ground the pin down so it didnt lockout the secondaries. So many things are wrong with the carb but I've adjusted everything. Im missing a little piece of the puzzle somewhere. Im hesitant to get a brand new carb but I'm getting nowhere.

 

I may have figured out one of the problems. I opened the carb up and replaced the needle and seat assembly. I torqued the seat down real good and replaced the gasket. Here is the problem. How do you properly set the float level. How do you know when the valve has fully seated. I push the float down to where i think it is closed but i can override that and push it down a little farther. Im unsure where the exact closed position is. What is a good way to set the float accurately. One way i read dead on 11/32 but with a little more effort i get it to read 4/32 or an 1/8. Hopefully this is where the problem is. O yeah and the old seat and valve assembly was loose when I took it out. I barely took any effort to unscrew it.

 

It's not how far down it goes, it's how far UP!

You hold down on the float fulcrum (the little "D" shaped metal bar that the float rotates around). Press down on it with one hand so that this fulcrum can't move around and so the float has a nice, firm, fixed point to rotate around. Then you press down on the INLET VALVE SIDE OF THE FLOAT gently with your other hand. Such that it bottoms out the needle valve inside the inlet valve and leaves the other side of the float "hovering" in mid air inside the float bowl.

Now with your THIRD HAND, you measure the distance from the top of the float to the top of the float bowl. Measure out on the very end of the float (but still where it's "flat" on top). THAT is your true float setting. 3/16" or thereabouts works just fine. Adjustment is done by bending (yes, BENDING!) the float arm- there is a built-in weak point in the metal arm specifically for this if you look at it.

 

You need to make sure also, that the D-shaped wire piece, is spread out wide enough, such that when the air horn is installed, it holds the D thing securely in place. If it's compressed too much, it will be free to wander up and down in its slot, and it will allow the fuel level to go WAY high when it wanders upwards (which fuel pressure will cause it to do).

 

Thanks for all your help guys. I finally reached the end of my rope on this one. I got everything back together and at first it seemed ok. Idle was awesome and started on the first try, it still was running rich but thats ok. So i stepped on it and flames came shooting out of the q-jet. I've already checked my timing and everything is good there. O well guess i should stick to what i know. Thanks again.

 

I know this is an old thread, but for some reason the ideas presented here never stuck by reading any other thread! I adjusted my Rich screw down 3 and my lean 5 turns and poof, all my part throttle issues and idle issues went away! YAY!!!!! I'm still throwing one code but my other one, a lean condition (code 44) went away once I did this! HECK YEAH! So, now I'm down to code 43 but otherwise the car runs and drives great! All gears, no lugging, no bogging, no feathering the throttle...just awsomeness!