Author Topic: High idle problem  (Read 3773 times)

Offline dwg30

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High idle problem
« on: March 09, 2008, 09:10:54 pm »
I have an 86 k-20 that has a quadrajet on it. I just bought this truck and the previous owner had the carb rebuilt right before I bought it. the problem is it is idling too high and when I went to adjust it I noticed that the adjustment screw was already almost backed all the way out. It is backed out so far that it is not even touching anymore but its still idling just guessing around 1000rpms. What could be my problem?

Offline VileZambonie

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Re: High idle problem
« Reply #1 on: March 09, 2008, 09:13:28 pm »
Do you have a throtlle kicker? The thing with the plunger and 1 wire going to it in the front of the carb?
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74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline dwg30

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Re: High idle problem
« Reply #2 on: March 10, 2008, 10:24:03 am »
Not that I noticed. Also the choke linkage is ziptied closed so it should not be a factor either. I will look again this evening but I didn't see any wires on the front of my carb.

If I do have it what is it and what does it do?

Offline VileZambonie

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Re: High idle problem
« Reply #3 on: March 10, 2008, 01:57:26 pm »
Well there ya go! If your choke linkage is zip tied closed #1 you are going to be super rich and #2 you'll never come off of the fast idle cam.
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74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline dwg30

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Re: High idle problem
« Reply #4 on: March 10, 2008, 02:18:52 pm »
Sorry about that I meant the choke is zip tied open.
« Last Edit: March 10, 2008, 02:40:13 pm by dwg30 »

Offline ccz145a

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Re: High idle problem
« Reply #5 on: March 10, 2008, 03:22:31 pm »
You need to make sure that zip tie is not interfering with the high-idle cam linkage, same general area.
1975 C10 Silverado LWB, 454CID, TH400, 10bolt 3.42
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Offline VileZambonie

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Re: High idle problem
« Reply #6 on: March 10, 2008, 03:51:45 pm »
Is the throttle linkage on the fast idle cam? Over by the choke you can see the step and the fast idle screw on the bottom.
,                           ___ 
                         /  _ _ _\_
              ⌠ŻŻŻŻŻ'   [☼===☼]
              `()_);-;()_)--o--)_)

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