Carb hesitation

[twodko]

This little ponderment occurs whether I'm at a stop light or driving down the road. For lack of a better description, the mill hickups very briefly. The engine runs smoothly otherwise. Is this caused by heat coming up from the windage tray effecting the gas before it hits the carb or maybe the carb itself? The car is a 69 440/727 bone stock, no headers and stock fuel line plumbing. Thanks.

Tom

[billschroeder5842]

Thnaks for the question--I that that answered too!

[Silver R/T]

does it have vapor separator installed?

[elacruze]

This little ponderment occurs whether I'm at a stop light or driving down the road. For lack of a better description, the mill hickups very briefly. The engine runs smoothly otherwise. Is this caused by heat coming up from the windage tray effecting the gas before it hits the carb or maybe the carb itself? The car is a 69 440/727 bone stock, no headers and stock fuel line plumbing. Thanks.

Tom

That could be almost anything. Can you give more description? RPMs? Throttle settings? How frequent? Humidity make a difference? Carb never cleaned inside? Points or electronic ignition? How old are the plug wires?

Eric

[twodko]

Hi Eric,

This hesitation occurs when the car is idling or at freeway speed everytime I drive the car and its very brief. We don't have a lot of humidity around here (NorCal), the car has electronic ignition and the plug wires are new as are the plugs. The carb etc looks spotless, its a fairly new Holley 750. The engine also runs rough when cold, sort of a lopping idle until it warms up. Carb tweaking has never been my strong suit.

Tom

[elacruze]

Just about any speed shop or good Auto parts will have a Holley tuning manual, or just look online. They're easy to tune if you have a book, you don't have to be an engineer. Just read and try.
Sounds like it may just be too lean-have you looked at the plugs? If they're white or nearly, you need to richen up.
Start by adjusting the float level, then the idle mixture, then move to the part-throttle jetting as necessary.
There are probably a lot of guys who can walk you through it here, too, but it's been too long for me to remember all the details.

Eric

[twodko]

Thanks Eric!

Tom