New holley but bad initial hesitation

[jb1dsl]

I have just replaced my edelbrock 600 with a holley 08475s 600. The hesitation when I punch it is terrrible. It is less than one second but it falls completely on its face, then it takes off like a rocket.I have tuned it the best I could and then let my buddy try it. He has been doing this for years. He says that I need to put in larger squirters for that initial fuel when I punch it. The carb is stock out of the box. What size come stock on this model and what size should I try first. It is a 289 with 9.8 comp, edelbrock performer rpm heads (1.90), Edelbrock performer cam, edelbrock performer intake, tri-y's, flowmaster full exhaust, c4 w/2500 stall, 3.55 rear gears, anything you need to let me know

 

[Az Pete]

I had the same problems with my 600 Holley. I had a bad stumble on hard take off plus it would almost stop if I accelerated hard from any cruising speed. Took some time but I finally bought the cam kit for the accelerator pump. $20 at most locations. It gives you 6-8 different cams to adjust how quick the acc. pump shoots the fuel. This took care of all my stuble. Local shops recommended not changing the squirters until I did this. This is on a fairly stock 302.

 

[jb1dsl]

That sounds just like the problem I have, bad at a stop and almost shut down while at any cruising speed. I will get a cam kit, which one did you end up using for your app. What are your motor specifics?

 

[fasttback]

Had the same problem - hesitation then it would take off. It turned out to be too much fuel coming in when the throttle was open suddenly. So, after playing with many different cam profiles and squirters I ended up with the smallest combination cam/squirter.

Basically a stock motor with headers and a four barrel carb (625 cfm). The carb is too big for the motor, but the motor will be modified soon.

When you start to switch out the carb parts, just do one change at a time and record what you are doing.

 

[Az Pete]

I have a stock 302 as far as I know. I am running the stock squirters and the black cam. One day I may play with others to see how they are. I have just a bit of black smoke on hard throttle now that I did not have before. My problem was a lean on acceleration. It has not hurt my mileage either except now it goes when I hit it.

 

[Dark Knight]

This will help...
http://www.carbdford.com/viewtopic.php?t=4737

 

[jb1dsl]

what cam and squirter comes on this carb stock? Do you guys think I have toomuch fuel or not enough fuel when I punch it. I also have a k&n flow control filter system on it, it was doing this before I put it on too

 

[jb1dsl]

holley tech support said to increase the squirter one size for less than a second and two for more than asecond, does this sound right?

 

[fasttback]

holley tech support said to increase the squirter one size for less than a second and two for more than asecond, does this sound right?

It's a starting point. I would buy the kit (as mentioned before) and you will have an assortment to choose from. Every application is different, so be prepaired to play with things. If I were to guess with your motor and a 600 cfm, I would increase squirter size (as Holley recommended) and cam size (duration and amount). Do one at a time. If it has less stumble = your going in the right direction...more stumble, switch things around.

 

[jb1dsl]

Is there a kit that has an assortment of squrters also not just cams

 

[Dark Knight]

http://www.holley.com/data/TechService/Technical/Carb Numerical Listing.pdf

You'll need the full model number. I'd change pump cams before messing with the squirter size. I went to the black cam too.

 

[jb1dsl]

dark knight
did you change your squirter size too or just the cam. Is a black cam less or more than what comes in this carb stock

 

[jb1dsl]

The squirter in the carb is a .031 the next size is a .032 then a .035, do you think I should order the .035 instead of the .032 if I order one because of the very slight change

 

[Dark Knight]

I just changed the cam.. I had the advantage of messing with it on a dyno to see if it was going lean or not..

What color cam do you have now? And have you adjusted the lever on the pump at all?

 

[mfp4073]

yeah, thats part of the voodoo of tuning a holley. I forget what I went with color wise, but I used the biggest cam and bigger squirters (I also messed with my jetting). My manual trasmission car will respond immediatly to a stab of the throttle at any speed to the point of breaking the tires loose in 2nd gear at 30-40mph or chirping the tires in 3rd gear at 55 both with no clutch. Its doable! Just keep trying

 

[jb1dsl]

i have whatever cam comes on this model stock. I have not adjusted the lever yet, any pointers

 

[mfp4073]

A lot is trial and error. Up the squirter cam, see how it does, lower the squirter cam, see how it does, up the jets, see how it does.......im telling you, one of the best tools to tune a holley is a chicken foot! BUT when they get dialed in....watch out!