Hi. I am looking for help with my edelbrock avs2 650 carb. The engine is a 340 4 speed mildly modified. Air gap intake,aluminum heads, headers, comp cam 231 duration. 480 lift. Vacuum at idle is 10" cruise 15".
Timing is set at 18 initial and 32 total. I have tried different timing spots From 20 intial to 35 total with no change. No vacuum advance as per my recommendations from ignition box company which is a rev n nator with a firecore distributor and their coil. Has summit plug wires and autolite plugs 3924 .035 gap
I have been through the carb and Manuals and believe i understand this carb well even though I'm new to carbs.
I have a o2 gauge with a vacuum gauge next to it which I can watch will driving.
The issue I have is from when i 1st installed this carb it run very rich. Cruise was 10.8:1 wot about 11:1. I have jetted it down much more then their calibration carts shows. Right now I have 98 jet with 73 37 rod and 95 jet in secondary. Orange spring. Middle pump shot.
Still cruises at about 12.8:1 wot about 12.5 which is good. Idle screws react well. Idle is about 13.8.
Now if I try and lean out cruise any more say to around 13.5-14 I get a very bad lean spot while under load. I still get get this lean spot now but it is not as bad. While accelerating with 15" vacuum down to say 5" (before power mode kicks in) my air fuel will start to lean out almost 3 points. I'll go from 12.8 to 15.0 ( once the power mode kicks in air fuel goes to about 13.5) if I lean out cruise to around 13.5 then when accelerating it goes to almost 17:1.
Engine will hesitate above 15:1.
I have tried to use to stronger spring but with the low idle vacuum it doesnt work right. Will bounce even if I turn up the idle more right now it's at 800rpm. I can make the pink work ok at 1000rpm but still will bounce if leaving from a idle as vacuum will drop a bit.
I have tested for vacuum leaks to the best of my knowledge I can't find any.
Have a psi gauge set to 5.5. Floats set to factory specs 7/16" and 1 "
Is this normal for it to lean out this much while under load? Any way to solve this?
Hoping someone has some ideas that way help me out as I have tried all I can think of.
I am new to carbs and older car but I feel like I know how this carb works but cant seem to figure out this issue. I have had no luck trying to find help online so I thought I would try here
Thanks for your time
