Rebuilding the Carburetor

IMG_1182In assessing the issue with the carburetor, I believed the issue was a clogged fuel bowl vent.  I turned to the experts by posting to the Corvette forum.  I described the issue and how I arrived at the diagnosis and received several responses.  I was on to something or so I thought, the vent bowl does need to be clear.  Then I received a response from Lars.  Lars, for those of you that do not know, is what I would deem the Rochester Quadrajet Guru.  Lars was quick to point out that I didn’t have a problem with the float bowl vent but rather, I created a problem with the float.  At first I was suspect of the response but after a couple more correspondence and on the advice of Lars, I decided the carburetor needed to be rebuilt.  It was yet another new adventure.

I ordered the Rochester Quad rebuild kit from Zip-Corvette and did a pile of research.  I requested the famous Lars papers which were happily provided by Lars.  I figured based on research that the rebuild time would be somewhere between 1 and 4 hours.  I prepared a working area in the garage using a white cloth on a table.  I pulled out the duct tape and used it to label parts as I took them off the carb.  This would prove to be helpful when putting it back together.  I removed the 9 screws from the top of the carb including the secondary metering rods and removed the top section of the carb along with the gasket.  I then flipped the carb over and removed the two screws from the bottom of the carb in order to pull the mid section and bottom bowl apart.  Once I pulled the top section, I could see right away that the float was damaged from where I had checked it… Lars was right.  Only problem was that the rebuild kit did not come with a float.  It was Friday night at 4:45 PM.  I started calling around.  I tried the local Corvette dealer and shop who told me they did not have part and they were not sure they could get it.  I ordered one online but it would not arrive until Wednesday of the following week.  I then called Advanced Auto Parts and to my surprise, they had one in the PA store and could have by 1:00 PM on Saturday.  Done.  Total cost $10.78.

I removed and cleaned the components of the carb and rebuilt as much as I could needing only to put the float in and complete the reassembly of the float bowl.  I picked the part up the following day and was able to the put the float in, secured the float bowl and put the carb back on the car.  I reconnected the throttle / choke, vacuum lines etc.  I started her up and she idled extremely low and nothing happened when stepping on the gas or manually pulling the throttle.  Something was wrong.

After doing more research, I discovered that the small arm on the throttle assembly need to clip into a small metal piece around the assembly inside the car.  I totally missed that.  I took the carb off the car, removed the air horn and began the tedious process of trying to get the arm connected.  After a bit of trial and error, I finally goth it seated and the air horn put back together.  I then reinstalled the carb on the car and reconnected the hoses and assemblies.  I turned the key and she started up.  I pressed the gas and she reved as expected.  I then left it at idle and made a small adjustment to the carb.  Bingo!  She is now idling at 500 RPM and is not not stalling.  The rebuild worked!

I am happy to share my experience with this issue with anyone who asks.  It was the first time I have rebuilt a carburetor and really, this is my first adventure with working on cars.  I have learned a lot by trial and error.

About C3Zen

From computer guy to car guy. Follow my journey of working on my C3 while enjoying good music and the occasional good beer.

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