Carb Tuning Question

stirling33

Member

May 14, 2005

126

0

16

Grayslake, IL

Jun 29, 2009

#1

• Jun 29, 2009

• #1

I am having what I assume to be some carb issues. Lately it will stumble when wide open then also surge while just cruising.

It does not happen everytime I run the car but often enough where I guessing something needs to be adjusted.

Is this a Jetting issue or what else could it be - I am running a standard 4160 Holley 600.

 

mrmustangman357

Member

Feb 11, 2007

763

3

18

Jun 29, 2009

#2

• Jun 29, 2009

• #2

check to make sure your timing is right, fuel pressure is good, and floats are adjusted first. after that pull the pugs and see how they look

 

jcode68

Active Member

Jul 15, 2003

892

1

29

Massachussetts

Jun 29, 2009

#3

• Jun 29, 2009

• #3

mrmustangman357 said:

check to make sure your timing is right, fuel pressure is good, and floats are adjusted first. after that pull the pugs and see how they look

Click to expand...

+1 on all of this and will just add that I had same symptoms even after the above was checked out. My plugs showed I was lean (were very light, some were white). I have a Holley Street Avenger 67 cfm. I increased my jet size by 4 increments and it is running really well now. The surging is gone and throttle response is great. Cheap and easy fix, but took a while to determine this was my problem.

 

stirling33

Member

May 14, 2005

126

0

16

Grayslake, IL

Jun 29, 2009

#4

• Jun 29, 2009

• #4

jcode68 said:

+1 on all of this and will just add that I had same symptoms even after the above was checked out. My plugs showed I was lean (were very light, some were white). I have a Holley Street Avenger 67 cfm. I increased my jet size by 4 increments and it is running really well now. The surging is gone and throttle response is great. Cheap and easy fix, but took a while to determine this was my problem.

Click to expand...

Thanks will look into all this tonight....

 

woodsnake

15 Year Member

Jan 16, 2007

1,352

15

69

Hicksville, NY

Jun 29, 2009

#5

• Jun 29, 2009

• #5

From here it sounds like ignition, check the wires around the distributor and coil for frayed ends, cracks, etc...

 

RGS0907

New Member

Aug 21, 2003

429

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0

New Jersey

Jun 29, 2009

#6

• Jun 29, 2009

• #6

stirling33 said:

I am having what I assume to be some carb issues. Lately it will stumble when wide open then also surge while just cruising.

It does not happen everytime I run the car but often enough where I guessing something needs to be adjusted.

Is this a Jetting issue or what else could it be - I am running a standard 4160 Holley 600.

Click to expand...

It's nearly always ignition. I wouldn't do anything to the carb until you fully check out your ignition. Get a vacuum guage & see what it reads. it should be at least 18.5" with a steady needle at 800rpm. If the needle fluctuates a little, it means that your timing is retarded. I did the same thing last night & pushed my timing to get 20" of vacuum & the car ran fantastic after that.

 

D

D.Hearne

New Member

Sep 29, 2000

11,730

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south louisiana

Jun 30, 2009

#7

• Jun 30, 2009

• #7

Also check the fuel filter, a clogged filter will also cause this. You ARE running a filter, right?

 

stirling33

Member

May 14, 2005

126

0

16

Grayslake, IL

Jun 30, 2009

#8

• Jun 30, 2009

• #8

D.Hearne said:

Also check the fuel filter, a clogged filter will also cause this. You ARE running a filter, right?

Click to expand...

I am running one - I will check that as well, thanks guys.