Author Topic: 350 carb only runs on full choke  (Read 9490 times)

Offline thelincolnguy

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350 carb only runs on full choke
« on: December 05, 2015, 10:46:13 AM »
Just bought an 85 c10 that the previous owner had installed a 350 in with a brand new carb. I got it home and when i went to run it, the choke was zip tied wide open. So i cut the zip tie and wired the electric choke to ignition power. Went to start it, it runs at like 2000 rpm closed choke. As soon as u hit the gas it dies. Dont wanna spend a lot of time or money on it. Just want it to run so i can get motivated to bolt up the torque converter and put the drive shaft in.
Thelincolnguy

Offline hatzie

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Re: 350 carb only runs on full choke
« Reply #1 on: December 05, 2015, 12:43:24 PM »
The stock 1985 choke runs through the oil pressure switch.  This keeps the choke from opening without the engine running.  It'll work the way you wired it.

If you leave the ignition switched on the choke should heat up and open.  If it doesn't it's adjusted wrong or the electric heater has failed.
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Offline thelincolnguy

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Re: 350 carb only runs on full choke
« Reply #2 on: December 06, 2015, 06:23:52 AM »
I watched the cd that came with the carb. If i unhook the choke linkage and turn the key, the plunger should move right away correct? If so then it just needs to be spun to the right orientation
Thelincolnguy

Offline Stewart G Griffin

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Re: 350 carb only runs on full choke
« Reply #3 on: December 13, 2015, 05:05:41 PM »
What kind of carb?

Offline thelincolnguy

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Re: 350 carb only runs on full choke
« Reply #4 on: December 18, 2015, 06:10:58 PM »
Edelbrock 600cfm i believe.
Thelincolnguy

Offline rich weyand

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Re: 350 carb only runs on full choke
« Reply #5 on: December 18, 2015, 09:41:23 PM »
Just bought an 85 c10 that the previous owner had installed a 350 in with a brand new carb. I got it home and when i went to run it, the choke was zip tied wide open. So i cut the zip tie and wired the electric choke to ignition power. Went to start it, it runs at like 2000 rpm closed choke. As soon as u hit the gas it dies. Dont wanna spend a lot of time or money on it. Just want it to run so i can get motivated to bolt up the torque converter and put the drive shaft in.

This could be real simple.  There are two idle screws, fast idle and normal idle.  I could make an Edelbrock do that if I set the high idle way too fast and the regular idle way too slow.  It could be that simple.
Rich

"Working Girl": 1978 K-10 RCSB 350/TH350/NP203 +2/+3 Tuff Country lift

Offline Irish_Alley

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Re: 350 carb only runs on full choke
« Reply #6 on: December 19, 2015, 07:17:34 AM »
did it run with the choke zip tied open?
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When you have eliminated the impossible, whatever remains, however improbable, must be the truth ~Sherlock Holmes

Offline thelincolnguy

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Re: 350 carb only runs on full choke
« Reply #7 on: December 30, 2015, 09:07:23 PM »
I heard a lot about the idle screws. And yes it ran with it zip tied open.
Thelincolnguy

Offline Hutch998

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Re: 350 carb only runs on full choke
« Reply #8 on: January 16, 2016, 01:47:42 AM »
I'm having the same issue with the same carb /engine. Did you check for vacuum leaks? If the tuning doesn't help or the truck dies when you open it, thats most likely the cause. If my choke opens even a little, it'll kill the engine. Also if its a new carb, theres a chance the guy before you didn't let the gasket seal right between carb and intake, which would cause a vacuum leak. Best way to test would be to take carb clean and spray around the intake/carb and vacuum lines, if the engine changes idle speed at all, you've found the leak.
78' K10
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Offline Irish_Alley

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Re: 350 carb only runs on full choke
« Reply #9 on: January 16, 2016, 07:07:34 AM »
i forgot about this post but like hutch said have you checked for vacuum leaks? although im not sure how well thats going to turn out since with the choke open it ran. but its still early and im not 100% thinking right. did you try and tune it?
If you can’t tell yourself the truth, who can you tell it to?~Irish_Alley

When you have eliminated the impossible, whatever remains, however improbable, must be the truth ~Sherlock Holmes

Offline thelincolnguy

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Re: 350 carb only runs on full choke
« Reply #10 on: January 17, 2016, 08:49:48 PM »
I was wary of the seal since the previous owner really didnt know anything about engines. He just bought a carb and put it on thinking it would make the truck turn into a bar of gold. And i have not checked for vacuum leaks. The underhood of the truck has been gutted and only what was necessary was put back in. (Not by me)o once the weather gets warmer i will get back onto this project.
Thelincolnguy

Offline jg1977c20

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Re: 350 carb only runs on full choke
« Reply #11 on: January 19, 2016, 02:12:00 AM »
do you know how to set the idle mixtures ? and have you done that yet ?
1977 c20 cheyenne camper special 8200gvw

Offline blazer74

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Re: 350 carb only runs on full choke
« Reply #12 on: January 19, 2016, 04:56:18 AM »
Carb only runs on full choke, but you say it also runs when the choke was wired open, both?

Offline thelincolnguy

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Re: 350 carb only runs on full choke
« Reply #13 on: January 20, 2016, 04:26:56 PM »
The choke was tied open when i bought it. I cut the zip tie and wired the electric choke. It only runs completely closed. And no i havent adjusted them yet. The only carbs im good with are kohler, briggs, and honda power equipment. Im a diesel mechanic by trade
Thelincolnguy

Offline jg1977c20

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Re: 350 carb only runs on full choke
« Reply #14 on: January 20, 2016, 06:14:50 PM »
at the front of the carb near the bottom theres 2 screws - turn both screws to the right (closed) be carefull to just lightly seat them then run both screws out to 3.5 turns each

on the choke side you should see another screw phillips , that is spring loaded and is easier to get at with the choke closed and fast idle engaged - turn that screw left a full turn ( sounds like someone messed with it and went too high )

on the throttle side is another screw flat blade - unscrew it until the scre doesnt touch the throttle arm -then turn it back in until it makes contact and go a full turn more in

start it up and turn the idle screw on the throttle side in more if needed

time how long it takes for the choke to fully open and post back

this just a ball park test the choke might be set too rick or too lean for the current weather assuming its winter where your at

start there and let me know what you find
1977 c20 cheyenne camper special 8200gvw