Holley 3605 Question
01-04-2011, 10:41 PM
#1
Heel & Toe
Thread Starter
Member Since: Dec 2010
Location: Houston-Area Texas
Posts: 18
Likes: 0
Received 0 Likes
on
0 Posts
Holley 3605 Question
My 66 (with K19) L79 has the original Holley 3605. Since I bought the car, it has a slight bog off idle as the accelerator pump comes in. No matter how I set the pump, the bog is there. Put a kit in the carb, and everything else is fine (i.e. idle is good, choke works fine, floats are set properly, power valve is not blown) I am beginning to think that the pump cam was changed somewhere down the line. Does anyone know the color of the pump cam on a 3605 Holley?
Thanks in advance for your help!
Thanks in advance for your help!
01-05-2011, 04:24 PM
#2
Team Owner
Member Since: Oct 2000
Location: Washington Michigan
Posts: 38,899
Received 1,856 Likes
on
1,099 Posts
Have you done the .015" pump lever clearance adjustment with the throttle plate held at the wide-open throttle position? If that's done correctly, you'll get an instantaneous pump shot with the slightest movement of the throttle lever. 
01-05-2011, 10:03 PM
#3
Heel & Toe
Thread Starter
Member Since: Dec 2010
Location: Houston-Area Texas
Posts: 18
Likes: 0
Received 0 Likes
on
0 Posts
JohnZ:
Thanks so much for your reply. I have done the .015" clearance adjustment and the hesitation is still there. My rationale was if the pump cam has been changed, the profile may be different enough to cause the problem on the transition off the idle circuit. I have also read the turning the idle screws 1/2-1 turn rich can also help eliminate the problem.
My thinking is that the carb should have a white cam, but what is on the car is a red cam. I have ordered a pump cam kit and will try the white cam to see if it makes any difference.
I will let you know the results.
Thanks so much for your reply. I have done the .015" clearance adjustment and the hesitation is still there. My rationale was if the pump cam has been changed, the profile may be different enough to cause the problem on the transition off the idle circuit. I have also read the turning the idle screws 1/2-1 turn rich can also help eliminate the problem.
My thinking is that the carb should have a white cam, but what is on the car is a red cam. I have ordered a pump cam kit and will try the white cam to see if it makes any difference.
I will let you know the results.
01-06-2011, 12:16 AM
#5
Heel & Toe
Thread Starter
Member Since: Dec 2010
Location: Houston-Area Texas
Posts: 18
Likes: 0
Received 0 Likes
on
0 Posts
The adjustment on the accelerator pump is to hold the throttle at WOT and adjust clearance between the pump arm and the adjustment "spring" to .015". This gives a full stroke on the accelerator pump and the "clearance" (.015") keeps the pump arm from damaging the accelerator pump diaphram.
01-06-2011, 04:59 PM
#6
Team Owner
Member Since: Oct 2000
Location: Washington Michigan
Posts: 38,899
Received 1,856 Likes
on
1,099 Posts
The adjustment on the accelerator pump is to hold the throttle at WOT and adjust clearance between the pump arm and the adjustment "spring" to .015". This gives a full stroke on the accelerator pump and the "clearance" (.015") keeps the pump arm from damaging the accelerator pump diaphram.
01-15-2011, 11:33 PM
#7
Heel & Toe
Thread Starter
Member Since: Dec 2010
Location: Houston-Area Texas
Posts: 18
Likes: 0
Received 0 Likes
on
0 Posts
Had a chance to work on the Holley Carb again today. I have learned a lesson today; NEVER assume the parts you are installing are good. I have rebuilt many Holley Carbs over the years, but this is the first time that I installed a carb kit in which the power valve was bad. I put a new power valve in the carb today and the driveability issues disappeared.
