Hey guys, gotta 83 ramcharger, 318, fresh stock heads, headers,flowmasters,1972 340 4bbl intake, brand new 1406 edelbrock 600cfm, truck runs great but will burn your eyes at idle. Was running 10psi(unknowingly), then got regulator and set at 4 psi,still rich. I can turn idle screws all the way in and still runs rich(but rough). was sure problem was with new carb,replaced under warranty,2nd new carb also running rich. (already checked float levels and for fuel entering carb body while running) I have come to the conclusion that I,m not burning the fuel properly. Don't know wich way to go with plug range or ignition timing(hot cold advance retard). any sugestions on this problem? (also running 4 dgree cam advance).

 

the 340 manifold could be the problem . it seems as tho it is different from the std 318 and 360 ..it fits only on the w2 heads... or u speeking of an edd. 340 manifold? if so ok u could have a manifold leak or a vac leak.

 

I thought maybe the intake was the problem too, but I just swapped it for a performer to match the carb. Still runs too rich and power slightly decreased with the edelbrock intake. Someone told me they think either the 600 carb is too much or the 4 degree advance is the problem. Just found out today I can now get historic tags, MD has changed from 25 to 20 year old min age of vehicle. So I no longer need to pass emmissions but would still like to figure this out. Someone please help!!!!!!

 

after reading ur post again it seems u set to much take ur cam back to 1 deg advance.. remember ur in a 5500# veh.. need low end

quinn

 

Sounds to me more like intake/exhaust valves not staying on the seats long enough,hydraulic cam?, check your lifter preload and/or do a leak down test. Are the header primary tubes glowing red at idle speeds? +4 cam advance will hurt top end power not low end.

 

have you tried tuning your carb? I had the same problem at idle with my 750 edelbrock carb,I bought a tuning kit with jets and metering rods, your carb manual has apage to help you tune it leaner i had to change the main jet lower and then try diffrent rods and springs until i found the right setting,trial and error seems to work best with this the book will get you close though i dont know your elevation but that needs to be taken into consideration also.