i just installed my new aem air fuel gauge in my exhaust and my reading at idle is way lean. 11 and sometimes 10. when i mash the gas it bogs and the gauge pegs at 18 very fast so its getting drown with fuel. i had a 37 shooter on it, and went back to a 25 stock one, still there. tried a lighter sec spring and got worse, going back to the brown one. the jet is a #49 stock was 51. how can i be soo lean at idle and then go rich soo quickly do you think the jet is still to big. My thing is that i have read ppls threads on how they tuned there holleys for their 300's and all put bigger jets in and bigger squirters. some even bigger power valves. mine though is the exact oppostite and i dont understand why. am i missing something. iv set the floats also and it has an electric pump on it. its maxed out a 8psi i dont have a gauge on it but im going to get one with a regulator. do u think i need to rejet to a smaller size also engine is smokey and stinks like raw fuel pretty bad fuel mileage is 9mpg driving like an ole man if i drove normal it would maybe be 6mpg

 

Umm, 10/11 lean and 18 is rich? If this is an air/fuel ratio gauge, then you should be shooting for 13-13.5:1. 10 or lower is pig rich (black smoke) and anything over 14:1 is borderline lean.
8 PSI is a bit much. 5-7 is more than plenty.
It appears to be rather rich at idle, and goes mega-lean as you open the throttle, rather the other way around. Check the floats, if they aren't too high (after lowering the fuel PSI a bit) turn the idle mixture screws in. They normally aren't more than 1.5-2.5 turns from bottomed.
Once the idle mixture is in the 12-13.5:1 range, start looking at the accel pump. Might need to adjust the spring tension on the pump rod, or even change pump cams.

 

wow im a dumb *******

 

Nah, just had a "blonde moment"......

Happens to the best of us, sometime or another.....

 

Go back to square one...the stock jets it came with and a pump squirter two sizes above stock as the starting point. Use a secondary spring from out of the middle of those available. Drive and try from there. The jets will be the last things to change once the lean holes at tip-in are covered. The secondary spring only affects the timing of the opening of the secondaries. The jets will not affect the idle but the float level does. Set the floats by the book...with the sight plugs removed, adjust up or down until there is only just the slightest dribble of gas running out of the holes. The jets will determine what the AFR is while cruising. The PV covers a possible lean condition that the accelerator pump/squirters does not cover especially when mashing the gas to pass from a cruise speed or otherwise under load. It's best to use an AFR gauge with a vacuum gauge to determine when the PV is actually opening and whether you want to go up or down with it.

I did not put bigger jets or a PV in my Holley. The first mistake I made was changing the jets...I actually went smaller...not good...bigger is not good either. Most seem to get in a hurry to change jets and it usually is not necessary. Also, if you are not running heat to your intake manifold, all the adjustments on the carb are pretty much a waste.