welldonecj7

iTrader: (13)

I have a gm crate 330 deluxe in my jeep, the motor is stock as it came from GMPP with shorty headers, 2.5 inch exhaust and it has an edelbrock carb on it. I reciently started doing some tuning on it trying to get it to run a little better, it was very rich at idle and seemed to be sluggish off the line. I adjusted the mixture screws on the front watching idle and vacuum. After getting this set it now runs much better off the line, seems to have much better throttle response, however it will not pull up high now, like it is leaning out, once it gets to about 4500, it doesnt want to pull any higher. Do I need to switch jetting or is it all in the mixture screws. Like i said the off idle is much better and seems to be not so rich at idle now, but now lean up top it seems.

twinturbo496

iTrader: (2)

How much fuel pressure?

What # is the carb? 1405, 6, 7, 10, 11?

These AFB's have worked well for me with almost the stock jetting. The significant modification I have done was drilling holes in the air door weights to make the secondary come in easier.

The items that can be adjusted are:

Idle mixture, idle speed
Primary jets
Secondary jets
Primary meter rods
Primary meter rod springs

And secondary air door counter weight (or spring tension if it is an AVS carb)

a website for mopar engines has a very good right up on adjusting these carbs. diamondbackengines.com

pancherj

I was once told that 99% of all carb problems are because of the ignition! Is your base timing and advance set up right?? If it is laying over at 4500RPM, it almost sounds like your mechanical advance isn't working properly...or, you have an HEI ignition and the module is going south.

welldonecj7

iTrader: (13)

First off I want to say thanks for the input, I really appreciate it.

I am unsure as to the exact model of the carb I will have to look into it to be sure. I know it is not an avs though. I do have HEI the only thing that leads me to believe it is carb related is that it was fine on the top end, however was seemed to be really rich down low and at cruise RPM, now with adjustment idle off idle accelleration and 95% of general drivablility is much improved. The only problem I am having is that it starts to not want to pull around 4200 at about 4500 you really notice it and then I just let off dont want to get it to lean if that is the problem. I want to take it out and do it then check the plugs to get a better idea, last time after I checked they looked good still.