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05-11-2005, 10:55 AM
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#1 |
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Senior Member
Join Date: Jun 2002
Location: Augusta Missouri
Posts: 804
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Can't get idle down ?
I just bought a 72 4x4 with a 350 and a Quadrajet carb. This truck had been sitting for quite a while. After I got it I replaced the gas tank and rebuilt the carb . Since I rebuilt the carb I can't adjust the idle down, its high like 2000 rpm plus. I can pull the throttle foreward and get it lower but it will not adjust any lower, feels like something is holding the linkage back. Any ideas, I have not taken the carb back apart yet. thanks
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05-11-2005, 11:20 AM
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#2 |
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Registered User
Join Date: Jun 2002
Location: Knoxville Tenn.
Posts: 3,058
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Check this 1st:
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56 Chevy Bel-Air 2dr. HT (purchased new) 71 Chevy Cheyenne SWB PU (502HO) 65 GMC short bed step--work in progress and my gofer |
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05-11-2005, 11:26 AM
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#3 |
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Senior Member
Join Date: Jun 2002
Location: Augusta Missouri
Posts: 804
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I am pretty sure it is ok, i will check it again. thanks
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05-11-2005, 01:01 PM
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#4 |
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Registered User
Join Date: Oct 2003
Location: Central Vermont
Posts: 8,538
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Check for vacuum leak's.
Last edited by vtblazer; 05-11-2005 at 01:01 PM. |
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05-11-2005, 02:36 PM
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#5 |
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Registered User
Join Date: Jun 2002
Location: Knoxville Tenn.
Posts: 3,058
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Next check to see that secondary blades are closing.
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56 Chevy Bel-Air 2dr. HT (purchased new) 71 Chevy Cheyenne SWB PU (502HO) 65 GMC short bed step--work in progress and my gofer |
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05-11-2005, 02:38 PM
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#6 |
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Registered User
Join Date: Apr 2002
Location: New Carlisle, Ohio,USA
Posts: 1,404
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Might check yer throttle linkage, and make sure that's not holding the carb open? Just my $.02 .
  
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LIFE AIN'T EASY WHEN YER FAT AND GREASY! GMC= Got More Class!  1970 GMC LWB, Fleetside, 350/4spd, Flowmaster "40's", 2002 GMC 16" Rallies, cowl hood,and added a bunch of options that weren't there when I started. 
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05-11-2005, 03:14 PM
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#7 |
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Registered User
Join Date: Sep 2003
Location: Franconia,N.H.
Posts: 1,029
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I had the same problem
I think you might have a vaccum leak. I had one from an extra gasket between the spacer and the carbafter that was out it ran great.
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(Only) Member of the CPNE Fan Club  Aint that the truth 67 C-10 350 with 3-speed tranny and 308 gears swb step  82 Z28 Camaro 355 small block over 350 hp and a borg warner super t-10 (blown engine) 72 Chevy K20 Suburban (future project) 70 Chevy K20 now 68 GMC K2500 2003 Chevy 2500hd ccsb 4X4 (daily driver) |
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05-11-2005, 04:27 PM
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#8 |
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Registered User
Join Date: Mar 2004
Location: Virginia beach, Va
Posts: 209
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throttle spring/linkage
Just like another said check the throttle spring and linkage. the linkage might need just some adjustment out, and some general purpose lubricant (wd-40, or whatnot) and the spring might not be the correct size, or might have not enough "springiness"
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~Christopher L. Orr 71 c20, 454- Stolen While Deployed. dynoed at 550 ft lbs, 425 hp at 3000 rpm (mustang dyno). TH400 3500 stall.... etc, etc. |
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05-11-2005, 05:08 PM
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#9 |
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Senior Member
 
Join Date: Mar 2000
Location: Saskatoon,SK,Canada
Posts: 2,476
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Check to make sure the choke is coming all of the way off. This will realate directly to jhow66's pic of the fast idle cam as the fast idle cam is controlled by the choke.
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Saskatoon, Saskatchewan Canada |
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05-11-2005, 06:23 PM
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#10 |
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Senior Member
Join Date: Jun 2002
Location: Augusta Missouri
Posts: 804
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Bottom linkage was stuck under choke, now it idles ok just runs like sh$t! I love playing with new toys! I don't think my fuel pump is pumping correctly, it doesn't seem to put out a good steady flow. There was so much crap in the old gas tank that there may be some still in the fuel pump. I will buy a new one tommorrow. Thanks for the help
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05-11-2005, 06:57 PM
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#11 |
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Registered User
Join Date: Jun 2004
Location: Beeville, Texas
Posts: 1,943
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If there's a lot of junk in the tank, it might be a good idea to run an extra filter between the tank and fuel pump.
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RJD 1984 Chevrolet C30 welding truck 454/SM465 1977 GMC C15 pickup 350/TH350 1970 Chevrolet C20 pickup 350/TH400 1970 Chevrolet K20 Suburban 454/TH350 1969 GMC 8500 478M V6/5 spd winch truck |
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