[MonteMan454]

Hello guys,
I swapped carbs (his is a 750 vac seondary Holley) for my friends which ran fine on his Olds 442. No change in vac levels. Infact my carb ran better and the vac levels were slightly higher. I couldn't hardly get it idle with my his carb. So now I can assume that the problem is not carb related.

When I re-installed my carb again and got it to idle I tried to spary carb cleaner in all the intake manifold areas and no change in idle speed.
Okay so maybe this is a intake vac leak which is very hard to find?? A few years ago I had the motor out (on a stand) and turned it upside down so maybe it ruined the intake gaskets due to oil infection???

One thing too is that these are small oval port 236 casting heads and the intake manifold is meant for large oval port. Maybe this is part of the problem?
I seem to remember an old post where the guy couldn't get good vac because of using oval heads and rec intake ports....

Kris

 

[gnicholson]

Try taking a pencil eraser and plug the idle vents while running. You should have a definite idle speed change; up if its to lean. They are the outer bleeds in the air horn. Check both sidesand if no change you have an idle circuit problem. The power valve has nothing to do with the idle circuit.

 

[MonteMan454]

Hello Gary,
I guess you are referring to the idle air bleeds located in the choke area? Should I put the eraser on all of them or just the primaries? I don't have adjustable air bleeds.
Yes the power valve is a main circuit system.

It is too bad I never took any vac readings 7 years ago when this motor was in another car. I wonder what levels it was back then? I wonder if it is worth changing the gaskets? They are likely a $20 item and around a 3or4 hr install time.
Thanks
Kris