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Discussion Starter #1
So here is the deal.

1980 Sr5 pickup (5 speed with 20r)

I rebuilt the carb. Been driving it for a week and running absolutely awesome... Like new. 0 issues what so ever.

Today, randomly it wants to dye if you clutch in or if its in neutral and you take your foot off the gas. So pretty much zero idle what so ever. Still runs fine when your driving tho...
it revs fine when sitting in neutral or clutched in too..It just doesnt idle.

what would cause this??

No visible vacuum lines unhooked, air filter is almost new, plugs, wires, cap, and rotor all low low miles.
what could it be?
 

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Bring it over Ill tune it for you.
Did you make sure the idle screw did not back out?
also make sure the base plate did not loosen.
 

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Discussion Starter #5
I will try that aswell...but after tinkering just now, it has something to do with the choke...
the choke flap is staying all the way open all the time. When you pull the cover to the air cleaner off and hold the choke flap most of the way closed it idles fine...
 

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disconnect vacuum switch to fuel decell system, located on passenger side front wheel well. about size of pill bottle with one vacuum hose & one wire connector and plug it. If it idles that is your problem. It may seem like its the choke but that will just cover up the problem.
 

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It may be on the intake itself. Its just a air valve. (decel valve)
Does yours have the fuel cut valve on the carb or is it the older non electric.
If it has the fuel cut valve make sure it has power(blown fuse)
 

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Discussion Starter #9
My truck did have the little valve in the intake itself that ran down to the exhaust heat shield...is that what your talking about?? Because I havent had that at all and never had any issues..

Any chance you can find pictures of what your talking about??
 

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Discussion Starter #11
thats what my engine bay looks like but I dont know what part you are talking about...nothing on the passenger fender well is about the size of a pill bottle with one vacuum line and one wire....
 

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Its round like a pill bottle the small advil ones.
with one wire connected to it and two vac ports.

I just tossed my 80 truck manual out last month. cant seem to find any pics of my truck when I rebuilt the 20/22r to show you a better pic.


I have a 76 20r sitting over at Jordans with the whole vac lines still hooked up if you need a part.
 

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just the vac line and plug it. It will not hurt anything run it that way if you find out which one it is that sucks vac all the time.
 

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Discussion Starter #19
still having the issue. Except when its cold...
when the truck is cold it will actually hold an idle, once it warms up it wont...
It also starts to backfire on decel and you can tell its running pretty rich.
the choke pull off functions (lever sucks in and out with change in vacuum).
So it still leads me to believe that its the choke thermostat. Guess I could still be wrong tho...
I dont know how to check a choke thermostat tho. Its just a wound spring that changes tension with heat.. But I dont want to just dump 45 bucks on a new one if thats not what it is.
 

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If its getting worse as you drive it. Sounds more like things are loose inside it like the jets. Have you found a vac leak?

As for the choke If it is closed when cold and opens when its warm than it works.
Make sure the EGR is not open all the time.(vac leak)
 
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