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holley tuning issue at cruise

  • Thread starter Thread starter mrmustangman357
  • Start date Start date May 30, 2009
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mrmustangman357

Member
Feb 11, 2007
763
3
18
Jun 9, 2009
#61
  • Jun 9, 2009
  • #61
ok now this is getting frustrating.

I undid everything I was trying.
I reset the throttle blades per brianj
I took out the main jets to see if I was actually in the idle/transition circuit at cruise.

driving at cruise (with nor IFR or airbleed modification) I AM in the idle/transition circuit, steady at ~12.5-13.0:1

after ~2100 rpm it starts to go to the main circuit. I know I'm in the main circuit because it goes DEAD rich from having no jets.
 

brianj5600

Active Member
Sep 19, 2003
1,964
2
39
Middle TN
Jun 10, 2009
#62
  • Jun 10, 2009
  • #62
That is a good test. I never thought of that. Here is a good tuning page. A little over half way down it talks about gas mileage and how to improve it. Carburetor Tuning the Scientific Way
 

mrmustangman357

Member
Feb 11, 2007
763
3
18
Jun 25, 2009
#63
  • Jun 25, 2009
  • #63
bump back from the dead!

So I got pissed off at taking the front bowl off after the 7th or 8th time! After reading this article, I learned alot more about the circuits:

Gas Mileage - Carburetor Tuning Techniques - Chevy High Performance

Basically what is happening is my idle circuit is dead rich at cruise then jumps into the mains. The article tells me I need to put wire in the IFR and drill the air bleeds. I got pissed off and drilled and tapped the air bleeds for set screws so I can adjust those too

PS: I also attached a paper clip to the secondaries to see if they are opening - nope they aren't. Diaphragm is good, so a lighter spring is in order. I have the edelbrock 750 on it until I can get the machine work done on the holley.
 
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