Author Topic: Quadrajet secondary flap spring??  (Read 3418 times)

Offline Cc7

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Quadrajet secondary flap spring??
« on: February 20, 2016, 08:33:32 PM »
Hey. I recently picked up a 350 with a 4 barrel( mid 80's) quadrajet on it. The motor runs ok but I'm pretty sure the tension spring for the secondary air flaps is either broken or missing. As the flaps have no spring left at all. My question is can I replace/install a new spring with the carb still on the motor? Thanks.

Offline Frank400

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Re: Quadrajet secondary flap spring??
« Reply #1 on: February 21, 2016, 04:16:37 AM »
Hey CC7, welcome to the forum.

    I doubt you could replace the spring with the carb bolted to the engine.  I'm not saying it can't be done but I would not try it myself.  It would take much more time than if you removed the carb and/or the air horn.  But the spring might still be there, just loose because someone loosened the small screw on top and did not "hold" the adjustment while doing so. 
 
  Any specific reason you want to replace it while it's on the car ?  By the way, what is the number on that carb ?


     Frank.

Offline Cc7

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Re: Quadrajet secondary flap spring??
« Reply #2 on: February 21, 2016, 06:40:27 AM »
When you say small screw on top . Do you mean the Allen key set screw underneath that holds the spring tension?  I was messing around with it a bit yesterday trying to get the tension"screw" to catch the spring and grab some tension but didnt have any luck ...it seesms like the tip of that spring is broken inside there or it just won't catch in the slot of the tensioner "screw". It's hard to tell because I can't see anything even when I climb into the engine bay... I will look up that carb number when I get home . The only reason I don't. Want to take it off the motor is because I don't really want to buy gaskets if I don't have to and it's cold out here now.... Thanks

Offline Cliff Ruggles

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Re: Quadrajet secondary flap spring??
« Reply #3 on: February 23, 2016, 03:20:47 AM »
The carb needs to be removed for that repair, and I would install a new plastic cam at the same time.  Those items come in our SR rebuild kit, and also available separately.....Cliff

Offline Cc7

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Re: Quadrajet secondary flap spring??
« Reply #4 on: March 11, 2016, 05:47:03 PM »
Thanks for the reply lots of knowledge on this site. Spring is changed and everything seems to be working good with the secondary air flaps. Now Im not 100% sure this is a carburetor issue but I'm thinking it could be. She starts good and idles ok and if slowly accelerating it works fine but it has huge lag from idle to flooring it like so much that will pretty much stall out if I floor it from idle. It's the same in gear or neutral. To me it seems like its getting too much fuel too fast and if you rev it up a bit then floor it, it seems handle the fuel a bit better  and make some power.  Are there any adjustments I  could try  on my Q- jet before I move on to timing. Thanks. ???

Offline 77cruiser

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Re: Quadrajet secondary flap spring??
« Reply #5 on: March 11, 2016, 06:15:59 PM »
Are you getting a good shot of fuel from the accelerator pump? Look down the carb with a flashlight & you should see a good stream on each side when you work the throttle. 

This one shows no fuel.   https://www.youtube.com/watch?v=z29Xwnkzn-M
Jim

Offline Cc7

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Re: Quadrajet secondary flap spring??
« Reply #6 on: March 11, 2016, 06:58:54 PM »
In the video it seems like he's checking with an empty bowl. I've checked mine and it gave 2 solid squirts but my bowl was full when I checked.

Offline Too Fast

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Re: Quadrajet secondary flap spring??
« Reply #7 on: June 25, 2021, 02:55:27 PM »
You do NOT need to remove the carburetor from the intake for this.  I know this is an old thread, but all you need to do is remove the upper air horn to get to the air flap spring.  I just replaced my spring today.  Updating this thread in case anybody else Googles this like I did earlier this week.

Offline Cliff Ruggles

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Re: Quadrajet secondary flap spring??
« Reply #8 on: June 25, 2021, 04:45:50 PM »
I don't recommend removing the airhorn with the carb on the engine.

You take a chance of dropping something onto the intake, down into the engine compartment never to be found again, or even worse into the carb which could find it's way into the engine.

In other words it's just a lot better idea to remove the carburetor from the engine and take it apart on the work bench vs laying over the fenders and pulling the top off of it.....

Offline Too Fast

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Re: Quadrajet secondary flap spring??
« Reply #9 on: June 30, 2021, 02:08:08 PM »
Lol.  Like a secondary metering rod down on the valley pan?  Ask me how I know. And, they don't stick to a magnet.  I used a slender screwdriver with sticky duct tape on the tip to retrieve it.  But that is great advice, if one does it like I did, there could be an issue with a lost screw if somebody is careless.