near stalling on deceleration

[Guest 240Z_72]

My SBC V8 likes to sputter and almost stall on me when I am decelerating such as coasting up to a stoplight. The idle speed seems fine, and it idles perfectly, but when I am cruising and then let off of the gas and roll to a stop, I need to keep my foot rested on the gas pedal slightly or the motor will almost stall. What causes this? There is a mild to mid cam in the motor, it lopes just a little bit, does this have anything to do with it? Or maybe a simple carb adjustment?

 

Thanks

Kurt

[Mike C]

Probably simple carb adjustment. I am assuming you have a Holley carb here...I would start by checking the float levels. If the front is too low or the rear too high this can happen. In the front the fuel moves away from the metering block and their is no gas for the idle circuit and the engine stalls. If the rear is too high then fuel can come out of the vent and effectively flood the engine since the throttle blades are closed there is very little air to offset all of the added fuel.

[Guest 240Z_72]

Yeah, it's a Holley 600cfm dbl pumper. How about my pressure regulator? Would lowering the pressure setting help any? I usually keep it on 4 or 5 and can't tell a difference between settings.

[Guest the_dj]

I had to open the idle air control valve a little bit. Is there a way to open the carb a tad to keep it from closing all the way? We're talking just an itty bitty bit here.

 

Sam

[Mike C]

Pressure should be fine where it is at, but a Holley will tolerate a little more pressure than that. My Holley red pump puts out 7psi at idle, but only 1 1/2 psi at WOT Needless to say, I have never run my nitrous system... WOT is where pressure is a real concern unless you are blowing the needle off the seat.

[Guest shortyz]

o the joys of owning a holley.

 

i could never get mine right either something was always screwed up with it.

 

then i bought an edelbrock.

 

best dam carb