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Topic: 1978 L 82 carburetor?

in Forum: C3 Engines

1978 L 82 carburetor?

Posted: 1/24/20 9:38am Message 1 of 6
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Mountain Home, AR - USA
Joined: 8/23/2019
Posts: 5
Vette(s): !978 Silver Anniversity Edition. L82

Hello My Carb is reving up way to high, Just got the car and it has been a garage king for life. It is all original, (engine) except for the AC which I just had done. Not an easy job. The carb upon starting the car idles way too high for about 10 minutes until it warms up nicely. The it will come down. But I am thinking of having it replaced. It is 42 years old. It is believed the less than 30,000 miles is correct. But can't prove. However all paperwork leads to that. Could someone tell me is better to keep the old carb. or put a newer more modern and if so can you recommend the best ones. I don't want to hurt the value. I know the car is not in super demand but it is almost flawless, just needs things here and there. And carb advice would be appreciated! And of course the clock does not work,,,,seems to be true on all. Thanks again. Michael




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Re: 1978 L 82 carburetor?

Posted: 1/24/20 4:46pm Message 2 of 6
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Burke, VT - USA
Joined: 1/23/2002
Posts: 7280
Vette(s): SOLD - "The Toy" - '70 Convertible
SOLD - "The Beast" - '90 ZR-1 (#682)
SOLD - "Betty" - '28 Ford Model A Tudor
Sold - "BLKBRRD" - '78 Pontiac Trans Am
"BLUBYU" - '04 Coupe

Hi Michael,

I'm by no means a carb expert but there should be an adjustment screw that can be fiddled with to bring the cold idle down to a reasonable RPM.

Keeping the original carb versus replacing it with a new one is a matter of personal preference.  Pulling the original and rebuilding it I would think will be less expensive than the purchase of a new one.  And after a rebuild the original will be nice and clean like a new one and should perform just as well as a new one.

My 2 pennies worth.




Jim Olson 

"The Toys"...!!!  Save the Wave!

Where I've been in a Corvette...!!!

Re: 1978 L 82 carburetor?

Posted: 1/24/20 8:57pm Message 3 of 6
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Cana, VA - USA
Joined: 7/3/2016
Posts: 372
Vette(s): 1975 Stingray 71 350 engine Flat top pistons Sniper fuel injection Hyperspark ignition Vintage Air air conditioning Borgeson power steering box

As far as a clock goes, unless you want to preserve the exact originality of your car, a quartz clock will perform flawlessly and  look original.  They run about $90.00.

You can tell an original from a quartz clock because the original second hand ticks off the seconds, whereas the quartz hand runs smoothly.

I had removed my original clock, took it apart and cleaned the workings including the points in it, and it ran for a day before quitting again.  The car now has a quartz clock.




   

Re: 1978 L 82 carburetor?

Posted: 1/25/20 11:02pm Message 4 of 6
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Scottsdale, AZ - USA
Joined: 5/23/2007
Posts: 617
Vette(s): 1981 Corvette Two-Tone Claret color, 4 spd, C7 Vert

The OEM should be a Quadrajet.  Like Jim says....sounds like you need a choke adjustment.   These are easy carbs to work on.  There is a book on QuadraJets that will help.



|UPDATED|1/25/2020 11:02:04 PM (AZT)|/UPDATED|



      Only 34 years together

Re: 1978 L 82 carburetor?

Posted: 1/31/20 4:33pm Message 5 of 6
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Overland Park, KS - USA
Joined: 7/9/2003
Posts: 914
Vette(s): 1973 Orange Metallic Coupe (orig owner), L82, 4 spd (WR), PS, (A/C & PW (I installed from wrecked 73)), leather, AM/FM Stereo, ran with '65 FI unit earlier & will again some day. 2023 Accelerate Yellow HTC Stingray

I assume you're using the correct starting procedure which is to push the accelerator to the floor and release it and then turn the key to start. After a short period, tapping the accelerator should allow the fast idle to drop down somewhat. If that's not happening and something is probably sticking on the carburetor.

As previously stated, the Rochester Quadrajet Carburetor is very easy to rebuild. I would suggest getting a copy of one or both of the following books. Rochester Carburetors by Doug Roe and Bill Fisher which is published by HP books and How to Rebuild and Modify Rochester Quadrajet carburetors by Cliff Ruggles published by Car Tech. 

I would suggest getting the rebuild kit from Cliff's High Performance.



|UPDATED|1/31/2020 4:33:27 PM (AZT)|/UPDATED|



1973 L-82 4 spd

Re: 1978 L 82 carburetor?

Posted: 1/31/20 6:12pm Message 6 of 6
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Grapevine, TX - USA
Joined: 8/26/2006
Posts: 1522
Vette(s): 1972 LT-1 convertible with factory air. 2017 Black Rose Grand Sport convertible.

Looks like Cliffs even has a rebuilding service.  Might want to give them a call and discuss that.




   

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