Choke position while engine is just warming up
Thread Starter
Racer
Joined: Nov 2003
Posts: 342
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From: Felton De
Choke position while engine is just warming up
Car is a 71 L-48 Auto w/ a holley 650cfm. Carb is from the 4150 series and has an electric choke. The car turns over fine, however its downhill from there. I've got all kinds of vacuum issues but thats another thread
One of the things I'm experiencing is an extremely rich mixture. My idle screws don't seem to do much. The engine will even after 3-4 minutes of warming, it just won't hold an idle. This is when I took a look at the choke. I'm totally ignorant as to what the choke position should be during startup and when the engine is cold.... never bothered w/ it til i had a problem!
When I turn it over the choke opens a little... maybe like a 1/4 inch. Then it either stays there, or returns to the almost closed position (still somewhat open, but not much at all). Even after like 3 or 4 minutes the choke is still almost closed... granted it is about 40 degrees out. Is this right? Or could this be one of the reasons I'm running so rich?? Tks!
One of the things I'm experiencing is an extremely rich mixture. My idle screws don't seem to do much. The engine will even after 3-4 minutes of warming, it just won't hold an idle. This is when I took a look at the choke. I'm totally ignorant as to what the choke position should be during startup and when the engine is cold.... never bothered w/ it til i had a problem!When I turn it over the choke opens a little... maybe like a 1/4 inch. Then it either stays there, or returns to the almost closed position (still somewhat open, but not much at all). Even after like 3 or 4 minutes the choke is still almost closed... granted it is about 40 degrees out. Is this right? Or could this be one of the reasons I'm running so rich?? Tks!
Racer
Joined: Jul 2007
Posts: 269
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From: WV
If you take your aircleaner off and look at the passenger side of the carb your going to see a little black plate with three screws holding it down. Loosen those three screws and turn that plate I believe to the left nto 100% on that but I believe it is marked in small increments until the idle is better. this will adjust the A/F ratio for when the choke is running
Race Director
Joined: Nov 1999
Posts: 10,643
Likes: 8
From: Foxfield CO 1970 Convertible
Well, when you are starting, the mixture should be very rich. Your choke sounds like it is about in the right position. It should look like it is basically closed, but cracked open just a bit. Don't worry - a ton of air will get through the smallest crack.
Is 3 or 4 minutes enough to heat up the engine? If so, then your choke should be opening. Is it hooked up to power correctly? When the engine is fully heated up, the choke should be vertical when you look at it.
Is 3 or 4 minutes enough to heat up the engine? If so, then your choke should be opening. Is it hooked up to power correctly? When the engine is fully heated up, the choke should be vertical when you look at it.
