I usually pump about 3 times after priming the carb (priming if it’s been 3 or 4 days since starting). Do you have the stock divorced choke or an electric choke?
Holley 4160 Cold Start Problem
Thread Starter
Intermediate
Joined: Jun 2025
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Holley 4160 Cold Start Problem
Had a new Holley 4160 installed recently in 67 Vette, 327/350 hp. Having difficult time at cold start, car turn over but won't fire. Have to feather gas peddle to get started. Suggestions?
Le Mans Master
Joined: Aug 2005
Posts: 6,542
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From: Temple Terrace Florida
How long does it sit between start ups? If my car sits weeks between using, I squirt about an ounce of fuel in the vent tube on the primary and it will start up immediately. Jerry
1967 Pedal Car Champion
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From: US-PNW
I think you're going to have to do a little more explaining and then some sleuthing.
Has it done this since day-1 of the new carb?
Only when cold?
As Tampa Jerry asked, does it cold start OK unless it sits for days or a week?
What is your starting procedure?
Do you know to set the choke before starting and how to adjust it if needed?
I agree that if my '67 Holley sits for more than a few days it takes some cranking for the fuel to get back into the engine.
Has it done this since day-1 of the new carb?
Only when cold?
As Tampa Jerry asked, does it cold start OK unless it sits for days or a week?
What is your starting procedure?
Do you know to set the choke before starting and how to adjust it if needed?
I agree that if my '67 Holley sits for more than a few days it takes some cranking for the fuel to get back into the engine.
Le Mans Master
Joined: Feb 2014
Posts: 8,946
Likes: 5,487
From: Richardson Texas
I think you're going to have to do a little more explaining and then some sleuthing.
Has it done this since day-1 of the new carb?
Only when cold?
As Tampa Jerry asked, does it cold start OK unless it sits for days or a week?
What is your starting procedure?
Do you know to set the choke before starting and how to adjust it if needed?
I agree that if my '67 Holley sits for more than a few days it takes some cranking for the fuel to get back into the engine.
Has it done this since day-1 of the new carb?
Only when cold?
As Tampa Jerry asked, does it cold start OK unless it sits for days or a week?
What is your starting procedure?
Do you know to set the choke before starting and how to adjust it if needed?
I agree that if my '67 Holley sits for more than a few days it takes some cranking for the fuel to get back into the engine.
Race Director
Joined: Apr 2005
Posts: 11,279
Likes: 2,141
From: Bowling Green, Kentucky
Sounds to me like the choke needs adjustment. Is it original choke, or did you install an electric choke??
If choke is adjusted correctly, engine should fire up quickly with 1 or 2 pumps of the gas (to both supply some initial fuel + set the choke) as long as it was run within the past week. If car sat for over 1 week without starting..... and especially if using ethanol laced pump gas..............the carb will be empty of fuel. This will require longer cranking or adding fuel directly into the carb bowl vents to get engine started.
Larry
If choke is adjusted correctly, engine should fire up quickly with 1 or 2 pumps of the gas (to both supply some initial fuel + set the choke) as long as it was run within the past week. If car sat for over 1 week without starting..... and especially if using ethanol laced pump gas..............the carb will be empty of fuel. This will require longer cranking or adding fuel directly into the carb bowl vents to get engine started.
Larry
Thread Starter
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Joined: Jun 2025
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First time on the Forum, thanks for the input. It's a new 4160 with electric choke. I did check to see if the choke is closing when gas pedal is depressed, it's closing.
Been having the problem since the carb was installed
I was told to press and release gas pedal once and car should fire up.
I try driving the car a few times a week so it usually doesn't sit more than a few days. If I pump the pedal more than once I get spitting and on occasion a bad back fire. I am aware that if the car sits for several days the gas in the carb will evaporate and one pump may not work.
Been having the problem since the carb was installed
I was told to press and release gas pedal once and car should fire up.
I try driving the car a few times a week so it usually doesn't sit more than a few days. If I pump the pedal more than once I get spitting and on occasion a bad back fire. I am aware that if the car sits for several days the gas in the carb will evaporate and one pump may not work.
Pro
Joined: Nov 2004
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From: Atlanta area
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Pro
Joined: Nov 2004
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From: Atlanta area
Also keep in mind that as soon as you turn the key to on position the electric choke begins heating up and opening up. Don’t wait more than a few seconds after initial turn-on to start the engine or you won’t have full choke.
Team Owner
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From: Sitting in his Nowhere land Hanover Pa
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Le Mans Master
Joined: Feb 2014
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From: Richardson Texas
If your Holley 4160 is set up correctly, when the fuel bowls are full one pump of the gas pedal will set the choke and inject a small amount of gas into the intake manifold, a second pump will add additional squirt...that's PLENTY of gasoline to start the engine. A more important step is to wait about 10-12 seconds after the second pump of the gas pedal to allow the liquid gasoline to vaporize...it's the vapors that ignite NOT the liquid gasoline. Too many folks think the more pumping of the pedal, the better. Not the case whatsoever...you're just going to flood the engine with liquid gasoline and wet foul the spark plugs. Of course, this is only 60 years of experience speaking here.
Last edited by leif.anderson93; Jul 8, 2025 at 09:54 AM.
Pro
Joined: Nov 2004
Posts: 531
Likes: 118
From: Atlanta area
If your Holley 4160 is set up correctly, when the fuel bowls are full one pump of the gas pedal will set the choke and inject a small amount of gas into the intake manifold, a second pump will add additional squirt...that's PLENTY of gasoline to start the engine. A more important step is to wait about 10-12 seconds after the second pump of the gas pedal to allow the liquid gasoline to vaporize...it's the vapors that ignite NOT the liquid gasoline. Too many folks think the one pumping of the pedal, the better. Not the case whatsoever...you're just going to flood the engine with liquid gasoline and wet foul the spark plugs. Of course, this is only 60 years of experience speaking here.
Drifting
Joined: Jun 2006
Posts: 1,608
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From: Durham ON
Starting my car when cold:
1- slowly push gas pedal to the floor 2 times, take your foot OFF the gas pedal.
2- turn key for 5 or 6 seconds if it does not start repeat step1 & step 2.
3- If it fires but did not start, repeat step 1 & step 2.
My car starts every time after sitting for a month or two, no problem at all.
1- slowly push gas pedal to the floor 2 times, take your foot OFF the gas pedal.
2- turn key for 5 or 6 seconds if it does not start repeat step1 & step 2.
3- If it fires but did not start, repeat step 1 & step 2.
My car starts every time after sitting for a month or two, no problem at all.
Thread Starter
Intermediate
Joined: Jun 2025
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Used your advice DSR, she fired up after the fourth pump. Just not used to pumping that much gas in the carb. Idles fine after a minute or two, runs great.
That gas evaporation must leave the carb dry as a bone after sitting for a day or two.
That gas evaporation must leave the carb dry as a bone after sitting for a day or two.
