Question on tuning edelbrock performer carb
Hello guys sorry to post again but I have done all that I can do with my engine. I have a 350 just freshly built. Edelbrock 600 performer carb Edelbrock rpm performer intake with a crane 222/230 @ 50 roller cam, world sportsman 2 heads. The engine idles perfect at 800 900 rpm and when you shift it it runs around 600-700 rpm. I put the carb on and set my main idle and had the idle mixture screws each out 1 1/2 turns I then turned each idle mixture screw in 1/8 of an inch at a time till my idle would start to get rough then I turned each of them back out a 1/4 of a turn and it ran excellent. For starting up it does excellent and runnin down the highway and cruising it has excellent throttle responce.
It was doing fine for a few days but now it will sit in idle ok but then when in park once in a while it will not stay in idle around 600 or 700 it will start to want to quit and the idle wants to drop to 500 or less. Also I had the idle set ok as stated above and I had to put the idle up again. I also have been havine dieseling issues when I turn it off. When I had my old edelbrock 750 on this motor is did not do all this and my edelbrock 600 is only about two years old and it looks almost like brand new and in excellent condition. The timing is already been set at 14-16 initial and is around 32-34 total by 3000. I don't know what to do to get the thing to quit doing what it is doing. I figured the idle mixture screws where to lean so I turned them each back out 1/8 of a turn but I don't want to do any more cause it will be almost at 1/12 turns again.
If I hook up my vacuum gauge how do I use that to fine tune this thing and what do I do if it does not want to hold an idle? As far as the dieseling goes I have not changed my timing at all and it is still ok and I should not have to retard it a few degrees to get it to quit the dieseling thing. Thanks guys for any help.