Holley Carb Question
Thread Starter
Racer
Joined: Jan 2008
Posts: 338
Likes: 0
Holley Carb Question
Hey guys,
I recently installed a new Holley 650 double pumper (#4777 i think) with mechanical secondaries on a mildly built 427. I started by setting the timing, float levels, and idle speed. The mixture probably still needs tweeking, but over all it runs good. No stumbling on acceleration or problems coming of idle.
However, the engine does have a tendancy to die when its in gear and idleing (ie: stop lights, very low speeds, etc.) The curb side idle is about 1100 rpm, which seems to be where the engine like to idle, and it is an automatic transmission. It is my understanding that the curb-side idle setting is seperate from the running idle. I have looked through the documentation and tried to find info on this (as well as Lars' great tuning papers) but I have come up with nothing. Any troubleshooting or advice would be greatly appreciated...
If I had to guess, I would think I'm missing something obvious here...
Thanks!
Keegan
I recently installed a new Holley 650 double pumper (#4777 i think) with mechanical secondaries on a mildly built 427. I started by setting the timing, float levels, and idle speed. The mixture probably still needs tweeking, but over all it runs good. No stumbling on acceleration or problems coming of idle.
However, the engine does have a tendancy to die when its in gear and idleing (ie: stop lights, very low speeds, etc.) The curb side idle is about 1100 rpm, which seems to be where the engine like to idle, and it is an automatic transmission. It is my understanding that the curb-side idle setting is seperate from the running idle. I have looked through the documentation and tried to find info on this (as well as Lars' great tuning papers) but I have come up with nothing. Any troubleshooting or advice would be greatly appreciated...
If I had to guess, I would think I'm missing something obvious here...
Thanks!
Keegan
Burning Brakes
Joined: Oct 2005
Posts: 845
Likes: 1
From: Columbus Indiana
Howdy, Keegan. Great carb! Of course, I'm biased, I've got one on my 350.
I set everything like you have so far, leaving the idle mixture tweaking for last. Over the years I've noticed that the mixture the car wants idling in neutral isn't always what it wants idling in drive.
The final tweaking I do to the idle mixture is always in gear, idling (wheels chocked, friends foot on the brake, emergency brake set, etc.....) I keep to the side of the car, I don't walk around the front.
Just something you might want to try.
John
Oh, my idle speed in gear is about 600. It tends to lope and pull annoyingly at anything below that.
I set everything like you have so far, leaving the idle mixture tweaking for last. Over the years I've noticed that the mixture the car wants idling in neutral isn't always what it wants idling in drive.
The final tweaking I do to the idle mixture is always in gear, idling (wheels chocked, friends foot on the brake, emergency brake set, etc.....) I keep to the side of the car, I don't walk around the front.
Just something you might want to try.
John
Oh, my idle speed in gear is about 600. It tends to lope and pull annoyingly at anything below that.
Last edited by seventysixvette; Oct 26, 2008 at 09:46 PM. Reason: normal scatter braining
