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Topic: Carb on my 81

in Forum: C3 Fuel, Emission Control, and Exhaust Systems

Carb on my 81

Posted: 4/24/07 4:56am Message 1 of 8
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Cuyahoga Falls, OH - USA
Joined: 4/4/2005
Posts: 2
Vette(s): 81 Coupe 4 Speed
I just put new plugs and wires, set the timing and I still have a flutter at low RPM, as far as I know it is the original carb with 61k, do you think that I need rebuild the carb or just  good ol adjustments.  It is the original Rochester


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Carb on my 81

Posted: 4/24/07 5:22am Message 2 of 8
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Duncanville, TX - USA
Joined: 11/8/2003
Posts: 20214
Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas
The carb probably does need some attention, as in an O/H. You may also have an EGR valve that is not sealing completely, causing a fluctuation of idle/slow speed RPM. Try dis-connecting the vacuum hose to the EGR valve and see if the "flutter" goes away. If not, then try "tapping" on the valve lightly with a small hammer, or the big end of a large screwdriver, and see if the RPMs change any. It's worth a shot.
The CCC carb is probably not metering the idle range fuel too well anymore...might be a good time for a check-up/surgery on it.


Joel Adams
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Carb on my 81

Posted: 4/24/07 5:27am Message 3 of 8
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Kendall Park, NJ - USA
Joined: 3/9/2005
Posts: 789
Vette(s): 1981 - 59 Beige over Cinnebar leather. Edlebrock top end, 2200 stall w/shift kit, 3:55s, Mufflex maniback exhaust, nice stereo, 16 in AREs w/BFGs
Al, I have 63k on my 81.  It did the same thing.  I had her rebuilt and flow tested to blueprinted spec.  UNREAL difference!  The seat-of-the pants dyno really feels it..  Kevin


Carb on my 81

Posted: 7/31/07 1:25pm Message 4 of 8
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Granbury, TX - USA
Joined: 7/30/2007
Posts: 20
Vette(s): 1981 Red/Red with Mirrored T-Tops
My 81 has been doing that lately. You can hear a flutter in the exhaust note at idle and there is a dead spot in the acceleration just off of idle. WOT works just fine so I'm guess the Rochester is in need of some attention... I'm a bit wary of trying to overhaul it since I've heard this year model is more complicated than the earlier ones. Maybe I can just make a trip to Duncanville to see Joel. Thumbs%20Up


Carb on my 81

Posted: 8/6/07 10:25am Message 5 of 8
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Scotch Plains, NJ - USA
Joined: 1/11/2006
Posts: 241
Vette(s): 1981 Corvette Coupe, Stock, Black on Black, 4 Spd
KEBO-
Any shop recommendations for the rebuilding service?
In NJ?



Carb on my 81

Posted: 8/7/07 9:42am Message 6 of 8
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Duncanville, TX - USA
Joined: 11/8/2003
Posts: 20214
Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas
[QUOTE=LilRed81]...Maybe I can just make a trip to Duncanville to see Joel. Thumbs%20Up
[/QUOTE]


Brang it on!
There's not really all that much different on yours from the earlier ones...just a couple of electrical parts...mixture control valve, and a TPS. The rest is just plain ol' Quadrapuke...


Joel Adams
C3VR Lifetime Member #56    

My Link


(click for Texas-sized view!)
             NCRS

"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"

Carb on my 81

Posted: 8/7/07 9:55am Message 7 of 8
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Granbury, TX - USA
Joined: 7/30/2007
Posts: 20
Vette(s): 1981 Red/Red with Mirrored T-Tops
Yeah, well, my electrical gremlins are having fun with those couple electrical parts right now. The best I can tell, I have four electrical gizmos on my carb:

1) Electric choke (labeled "choke heater" on my diagram)
2) Throttle Position Sensor
3) Mixture Control Valve
4) Idle Speed Control (labeled "idle stop solenoid on my diagram)

Makes a guy contemplate putting a simpler Q-jet on there...

Corey



Carb on my 81

Posted: 8/7/07 5:45pm Message 8 of 8
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Mounds View, MN - USA
Joined: 5/24/2007
Posts: 1031
Vette(s): 70 LT1 coupe, 69 350 HP coupe, 69 390HP 427 coupe, 71 LS5 convert, 85 coupe, 93 coupe
If you don't have anyone local, contact The Carburetor Shop in St. Paul, MN  651-770-3505.  They do all sorts of carburetors and injectors.  They are top quality and reasonably priced.


in Forum: C3 Fuel, Emission Control, and Exhaust Systems


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