carb headaches

[axstang]

I need some advice. I own a dedicated 1988 autocross Mustang. The issue is that under hard deceleration along with sharp turns the engine stumbles. Once the car is staightened back up the engine responds great. Here is what i have and what I've done. 302 .040 over. steel gt40 heads 1.7 rockers. lunati .512 292 dur cam. torker 289 intake. MSD ignition (DIstributor, box, and coil) holley blue with aeromotive regulator. 1407 (750 cfm) carb. I have verified 5psi at WOT. Rechecked float level and drop, readjusted idle mixture screws. Moved the plunger to the bottom position of the carb. Checked timing (although the car accelerates great) Checked to make sure the fuel pickup is not occluded, enough fuel in the tank.
Side note, I have in the past ran a 1405 (600 cfm) without issue. Maybe the carb is to big? I have not had a problem with the car on track days or hillclimbs. Thoughts, ideas, and/or opinions welcome.

 

[BlownFiveLiter]

This isn't really a tuning issue, since you're not asking about your EEC and one of the available tuning devices for it. That being said, are you sure the baffles in the tank are ok? The presence of gas in the tank is one thing, but under a hard deceleration, or turn, you're probably causing the fuel to slosh away from the pickup. Granted the float bowls should have enough fuel in them to sustain you for a turn, it's possible that they don't. I'll let someone with more carb knowledge chime in (and also request that someone move this into 5.0 Tech).

 

[axstang]

I did check that the pick up was within the baffle. I recall that I made a hard left turn which would have forced the fuel to the right side of the tank where the pickup is located. Thanks for the heads up on forum sub categories.

 

[jrichker]

Some carbs have or need a baffle in the float bowl to keep the fuel from moving away from the main metering jet and accelerator pump. Disassemble the carb and see if it is one of the carbs that fall in that category.

 

[axstang]

I checked, the baffles are in the bowls. Any thoughts on the spring loaded needle and seat for edelbrock carbs?

 

[Meep]

Edlebrocks Don't Like Hard Turns

Similar issue with my Edelbrock. Hard corners would make it stumble and it would clean up when you hit the skinny pedal. I would look at the bowl vents overflowing into the intake. If that's the case, Holley makes a carb just for your setup with centerhung floats and modified vent tubes.