Author Topic: high idle sticking  (Read 14169 times)

Offline brewdogg

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high idle sticking
« on: September 28, 2009, 04:48:46 PM »
Hello,

I bought a '79 Chevy recently and am very happy with it. Only problem I have is that the high idle won't kick down for a long time. My question to all of you is, how do you adjust the high idle? It is a 4 bbl Rodchester carb on a 350 motor. Any help would be great.

Thank you

Offline VileZambonie

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Re: high idle sticking
« Reply #1 on: September 28, 2009, 08:12:19 PM »
The fast idle screw is under the choke on the fast idle cam. Verify the choke vacuum break is working.
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74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline brewdogg

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Re: high idle sticking
« Reply #2 on: September 30, 2009, 02:51:20 PM »
The idle speed is fine it's just that it takes forever for it to kick down. Do I need to adjust the choke or could it just be sticking? I sprayed it down with carb cleaner and a bit of WD40 and worked it in. But still no difference.

Offline Donut

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Re: high idle sticking
« Reply #3 on: September 30, 2009, 04:04:38 PM »
Will it kick down if you "blip" the throttle?
'73 Chevy K-20 ***SOLD***
350/tbh350/np205
My plow was half price if i took the truck with it.

'86 C-30 dually, 454/tbh400

Offline brewdogg

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Re: high idle sticking
« Reply #4 on: September 30, 2009, 04:25:18 PM »
No it won't. At least not until it has warmed up for about ten minutes.

Offline VileZambonie

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Re: high idle sticking
« Reply #5 on: September 30, 2009, 07:36:56 PM »
Quote
Verify the choke vacuum break is working

,                           ___ 
                         /  _ _ _\_
              ⌠ŻŻŻŻŻ'   [☼===☼]
              `()_);-;()_)--o--)_)

74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline brewdogg

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Re: high idle sticking
« Reply #6 on: October 01, 2009, 03:51:34 PM »
How do you verify the choke vacuum break is working?

Offline jaredts

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Re: high idle sticking
« Reply #7 on: October 02, 2009, 12:58:59 PM »
The choke vacuum break is a small vacuum dashpot on the passenger's side front of the carb.  After you start the engine it should pull in.  If you aren't sure start the engine and pull the rod out a little that comes out the dashpot and release it.  Vacuum should pull it back in.  Do you know what type of choke you have (electric, divorced, hot air)?  Each type has a different mechanism for heating and opening the choke.  That's where I would probably start snooping around.

Offline brewdogg

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Re: high idle sticking
« Reply #8 on: October 07, 2009, 03:15:40 PM »
The choke vacuum break is working. I have an electric choke and I leaned it down a bit but that doesn't seam to make a differance. I will keep fiddeling around with it. Any suggestions?  :-\

Offline jaredts

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Re: high idle sticking
« Reply #9 on: October 07, 2009, 08:47:39 PM »
Start the engine and check for voltage at the choke wire.  While the breather is off wait until you think its idling too high (I assume its not too high at startup) and quickly snap the throttle a few times.  If it kicks down its still gunked up.  If still nothing maybe give some more info.--rpm at startup and after a few minutes when its too high (assuming you have a tach).  Have you set the fast idle screw yet?

Offline Jim Rockford

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Re: high idle sticking
« Reply #10 on: October 10, 2009, 06:25:10 AM »
WD-40 IS NOT A LUBE. >:(
1973 k20 Camper special
1980 k20 custom deluxe
2004 Crown Vic LX sport

Offline VileZambonie

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Re: high idle sticking
« Reply #11 on: October 10, 2009, 07:35:39 AM »
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              ⌠ŻŻŻŻŻ'   [☼===☼]
              `()_);-;()_)--o--)_)

74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline Jim Rockford

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Re: high idle sticking
« Reply #12 on: October 10, 2009, 04:41:53 PM »
WD-40 was developed by the military in the 50s as a rust preventative solvent and de-greaser to protect missile parts. It quickly became a household item when people discovered it had thousands of other uses as a cleaner, rust-prevention agent, and more
1973 k20 Camper special
1980 k20 custom deluxe
2004 Crown Vic LX sport

Offline VileZambonie

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Re: high idle sticking
« Reply #13 on: October 10, 2009, 05:03:23 PM »
Quote
Known as "the can with thousands of uses," WD-40 protects metal from rust and corrosion, penetrates stuck parts, displaces moisture, and lubricates just about anything

http://www.wd40.com/
,                           ___ 
                         /  _ _ _\_
              ⌠ŻŻŻŻŻ'   [☼===☼]
              `()_);-;()_)--o--)_)

74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline Jim Rockford

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Re: high idle sticking
« Reply #14 on: October 10, 2009, 06:39:13 PM »
sorry, you can't degrease and lube at the same time. The problem with it is it evaporates, that is why it was so good to use on old cars when the distributor got wet. yes it might look like its lubing something, but it doesn't last a day. PB blaster is a penetrate and a lube.
1973 k20 Camper special
1980 k20 custom deluxe
2004 Crown Vic LX sport