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Old 04-06-2017, 10:15 PM   #1
68longhorn
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Choke problems?

My 86swb has intermittent hard starts cold. It has a 305 with a quadrajet. It will crank for a while and requires pumping the gas to start. When it starts it usually blows black smoke, won't idle and won't accelerate. After about 30 seconds it clears up and runs fine. It also has started losing power and smoking a few times while driving. That normally clears up after a few revs but today I had to wiggle the choke linkage to clear it out. What do I try to fix this?
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Old 04-07-2017, 07:41 AM   #2
cadillac_al
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Re: Choke problems?

If it's blowing black smoke you probably don't need to pump it so much.
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Old 04-07-2017, 11:18 AM   #3
68longhorn
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Re: Choke problems?

When it blows the smoke the choke seems to be suffocating it and if i don't give it gas it stalls and won't run
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Old 04-07-2017, 11:26 AM   #4
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Re: Choke problems?

with engine warm & air cleaner off ,choke flap should be straight up&down. if not it just needs adjustment. if it is probably not the choke. good luck.
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Old 04-07-2017, 12:07 PM   #5
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Re: Choke problems?

You could check and make sure you choke pull off still works.
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Old 04-07-2017, 03:25 PM   #6
truckin 79
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Re: Choke problems?

Sounds like it is running rich and so black smoke. So can be a couple things, the choke is sticking shut or needs adjustment, there is some garbage stuck in between float and seat or carb is leaking from well plugs. Like has been said start truck without air cleaner and see what angle choke butterfly is at and adjust accordingly. Does carb stink like gas then it is probably flooding. If everything else seems normal then maybe well plugs leaking down or could be a combo of things. Possibly even a vacuum leak
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Old 04-07-2017, 05:22 PM   #7
68longhorn
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Re: Choke problems?

When it does this the choke butterfly is not fully open. It does it intermittently. I have to pull the linkage on the carb to get it to open. If it is sticking what can be done to fix it?
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Old 04-10-2017, 01:22 PM   #8
tucsonjwt
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Re: Choke problems?

My $12 response is always convert to a manual choke. You will always know when your choke is open and when it is closed. Get the kind orf manual choke with a closed (black plastic) outer sheath so you can lube it. The cheaper styles have an open sheath to facilitate routing of the cable, but you can't lube them without removing the entire cable because the lubricant comes out around the open sheath. I have never had any luck with any "automatic" choke, but others posting here say they always work correctly and I just don't know how to adjust a choke.
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Old 04-10-2017, 06:55 PM   #9
truckin 79
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Re: Choke problems?

You can spray with lubricant around linkage, not to much and work it back and forth. You could even use a toothbrush to get lubricant into springs and arms.
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Old 04-10-2017, 07:01 PM   #10
Cadillac Kid
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Re: Choke problems?

Truckin 79' has good advice.

Once the truck fires up, the choke pull off (small vacuum can on the carburetor) should slightly open the choke plate to allow more air into the carb. If the truck just started and the choke plate is 100% closed something is wrong. The choke plate should never actually be all the way closed.

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Old 04-10-2017, 07:14 PM   #11
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Re: Choke problems?

Quote:
Originally Posted by Cadillac Kid View Post
Truckin 79' has good advice.

Once the truck fires up, the choke pull off (small vacuum can on the carburetor) should slightly open the choke plate to allow more air into the carb. If the truck just started and the choke plate is 100% closed something is wrong. The choke plate should never actually be all the way closed.

-Gavin
And if it is closed all the way it won't run!
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