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Can someone explain to me how a quadrajet works? I don't understand how my secondary is supposed to open?I replaced fuel filter and I think I'm not getting enough fuel cause I can't floor it or give it more than half throttle in all gears. If I do the car starts shaking I just dont whats not working. It doesn't seem like it will open with vaccuum.
If anyone is near northern VA and can help i got a nice ribeye and some beer if they can help me understand.
I appreciate it. Been learning on this car. Never had a carbed motor before
Push your finger down on it......on the secondary air flaps.....do they open freely and snap shut with a slight spring load? Did you post in the C3 page about this on FB? If so, I am the one who told you to stick a filter in it first.
E-Mail Lars as stated above......have him send you his papers and read them all....tell him what is going on. You need to properly set timing before you do anymore investigating as well.....
Push your finger down on it......on the secondary air flaps.....do they open freely and snap shut with a slight spring load? Did you post in the C3 page about this on FB? If so, I am the one who told you to stick a filter in it first.
E-Mail Lars as stated above......have him send you his papers and read them all....tell him what is going on. You need to properly set timing before you do anymore investigating as well.....
Jebby
yup I replaced the fuel filter, the one in it was clean but I replaces it. It's been a bunch of things here lately. Found out I needed new rear calipers, pads and rotor. Got all taken apart bought a new "brake line" that I was told I needed lol. It was the flex line that connects to the caliper hard line. So now I need that aswell. I appreciate yalls help. I thought I emailed Lars, guess I forgot from work stuff.
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
what you were pointing at is the choke pull off. Push it in and watch the linkage its attached to move, then open the choke valve while you have it pushed in and see what other linkage moves behind that black plastic disc which is your choke. In your pic theres a tip of a rod (secondairies rod) with a post through it. That will have a swinging arm that prevents it from moving. When the car is running you will see choke pull off pull on that linkage which will allow the choke to open once it gets to the required heat setting. When the motor is cold there is a small lever that holds the secondaires closed. If you look on the drivers side you can see the lever that travels through the carb Secondaireies and see that it is spring loaded. When you move the throttle, the lever for the secondairies will move but only the spring will twist until that lever on the other side is out of the way. if you find the lever for the choke on the passenger side, you can hold it open manually, open the choke valve, then flip your thottle and see the bottom valves move. You have to manually open the top flap and hold it open to see the lower valves open. the top opens with the air flow when the air is drawn in.
Here is a video of a different style choke pulloff on a quadrajjet but you will see that lever that I was trying to explain. If someone messed with it or the choke pull off is bad it wont release
Now if you have everything connected correctly, and the choke works and with the engine hot you can see that the secondairies are working, you may be experiencing the quadrajet bog. Its what happens when that secondairy air flap open too quickly and your car runs lean all of a sudden. there is an adjustment for that doors spring to make it resist openning too quickly. But make sure your choke is functioning correctly first before messing with the flap
Last edited by Rescue Rogers; Jun 7, 2020 at 12:12 PM.
what you were pointing at is the choke pull off. Push it in and watch the linkage its attached to move, then open the choke valve while you have it pushed in and see what other linkage moves behind that black plastic disc which is your choke. In your pic theres a tip of a rod (secondairies rod) with a post through it. That will have a swinging arm that prevents it from moving. When the car is running you will see choke pull off pull on that linkage which will allow the choke to open once it gets to the required heat setting. When the motor is cold there is a small lever that holds the secondaires closed. If you look on the drivers side you can see the lever that travels through the carb Secondaireies and see that it is spring loaded. When you move the throttle, the lever for the secondairies will move but only the spring will twist until that lever on the other side is out of the way. if you find the lever for the choke on the passenger side, you can hold it open manually, open the choke valve, then flip your thottle and see the bottom valves move. You have to manually open the top flap and hold it open to see the lower valves open. the top opens with the air flow when the air is drawn in.
Here is a video of a different style choke pulloff on a quadrajjet but you will see that lever that I was trying to explain. If someone messed with it or the choke pull off is bad it wont release https://www.youtube.com/watch?v=_mwX06-3LV8
Now if you have everything connected correctly, and the choke works and with the engine hot you can see that the secondairies are working, you may be experiencing the quadrajet bog. Its what happens when that secondairy air flap open too quickly and your car runs lean all of a sudden. there is an adjustment for that doors spring to make it resist openning too quickly. But make sure your choke is functioning correctly first before messing with the flap
Yeah I searched youtube up and down for hours trying to understand. I got a grasp kinda. I have a buddy who is going to help me diagnose this beast. Also he said I should use some seafoam in the carb and remove the line from the brKe booster and suck in a bottle of seafoam let the car die wait 30 mins then drive the hell out of it.
Oh, gawd.... No wonder these cars and carbs are so screwed up. I'm going to the Studebaker Forum.
Reason the cars all screwed up is it had been driven for 2000 miles in the past 12 years. And not taken care of. Not 1 oil change, or any other maintenance from what I've been told.
I am not an advocate of snake oils.......even if you do have something in the carb bowl, breaking it up with a product is just going to make **** worse. Sucking it in the engine will do absolutely nothing but make you think you achieved something....which you won't. It is right up there with the Tornado, Slick 50 and E3 spark plugs.
2025 C3 ('68-'73) of the Year Finalist - Unmodified
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This is a properly working Quadrajet. If you watch the video frame by frame you can see exactly how it works. Adjustments are fairly easy to get the secondaries functioning as they should... The tension on the secondaries spring needs to be adjusted with the engine off and so they bounce open and shut with a light touch of a finger...
Last edited by Daveinspain; Jun 10, 2020 at 01:14 PM.
Quadrajet help seriously
