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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: Boone83K10 on December 05, 2013, 10:34:56 am
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background info first: 350 with a Holley 4175 (80555C) with electric choke.
I am currently adjusting my choke setting. I have the high idle set to 1500 RPM as per factory (once it gets there..read below) and verified by a good tach. I have the choke coil set 4NL which is one notch leaner than how it came from Holley, this works better in the thinner air. Confirmed 12V source when key is switched on.
My problem is that the qualifying choke vacuum pull off is right on the factory setting of .096" but that makes my engine run rough/low idle for the first 30 seconds. When the coil relaxes some more it idles up more to the 1500 rpm and does fine. Instructions say to adjust the rod linkage by bending it some. I tried with some needle nose to no avail. I know you can buy a tool but have any of you had success with a more "redneck" way?
the linkage in question is the u shape next to the choke pull off.... says to bend that U however you need to adjust the amount that it pulls the choke flap open...
(http://cdn2.autopartsnetwork.com/images/catalog/brand/holley-performance/full/0-80555c.jpg)
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Standard method is one pair of pliers to squeeze the loop together and increase the plate opening, two pair of pliers to spread the loop and close the plate.
Or, you can u-groove the end of a 3" long 3/8" bolt and make a tool that fits the wire diameter of the link.
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Standard method is one pair of pliers to squeeze the loop together and increase the plate opening, two pair of pliers to spread the loop and close the plate.
Or, you can u-groove the end of a 3" long 3/8" bolt and make a tool that fits the wire diameter of the link.
it struggles to get in there past the piston... should I only attempt to bend it after having the engine up to temp to assist in heating it up..obviously shouldn't heat it with a flame near the engine.
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The choke linkage adjustment you're performing is generally done on the bench, so whether the engine is hot or cold is immaterial. You can adjust the choke thermostat temporarily to relax plate closing, bend the linkage, then reset the choke to check your work. Really, you can use whatever method is most convenient for you.
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Well I am really just trying to nurse this carb until I get my Demon 1901... I am absolutely enamored with that carb after seeing it do wonders on my buddy's Monte Carlo.
So I don't really wanna take it off... I will try it again on the truck.
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I was trying to point out that you don't need to have the engine hot or cold. You can make the adjustment on the engine by relaxing or tensioning the choke stat to gain access to the link. Just remember to return the choke stat to its correct setting when you're done. :)
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Didnt get a chance to try to bend it. I decided to wait til that cold front gets to NC and see what happens. It was cold here when I started adjusting but since you have to wait til next.morning to tinker again...it got warmer and I dont want a false reading when its only 40 instead of the normal 20 or colder in winter time here.
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It still gargles for 20 or so seconds until the plate opens up. Think I could just remove the pull off and bend the linkage with it off the carb?
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Took the choke pull off ..off. I was able to bend the linkage some. Now the choke plate open about 1/4 inch when the truck cranks. Idles up to 1500 rpm immediately and does not stumble or gargle at all.
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Good job!
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thanks, now it won't be so hard for it to stay running on 15 degree mornings.