i have a rebuilt 327 .030 over rebuilt with about 330 wheel h.p. and when the car is cold (it was 64* earlier n texas) it will idle at 500 but when it warms up it will idle normally at 700 or so, after driving it for a while it would steadily idle at 1,000+, im not too harsh on the car it was at 5,000 3 times today when i shifted which i do occasionally but i dont know what happend it just idled at 1,000 and even when i would adjust the idle speed it would stay the same i think i did see some smoke coming from the number 2 exhaust valve and slight valve tick, no i didnt blow a head gasket... any ideas? the carb is an edelbrock 750 c.f.m #1407. its never done this before even when im really hard on it...

Are you running an electric choke? Possibly the spring inside is broke and the choke is not opening all the way when warm and your running on the high choke cam instead of the idle screw. Take off your air cleaner and see if the butterfly is open all the way when warm.

May check your secondarys,,might be staying open slightly.I had same problem with a carb I had. If you bend the rod that is right behind the linkage to where it will push butterflies shut when off the gas it may cure problem. Also maybe check your mechanical advance in dist. could be sticky and would cause a higher idle.Hope you figure it out.

the carb is an edlebrock manual choke that is not hooked up. i hope it isnt a distributor problem as it is a brand new petronix. now that it has cooled completley let since last night let me go check everything, its never done this before...

Do you have the manual choke wired open?

ok i checked it, when i got in the car i pumped the gas 2 times as usual but it would not start, i thought it was flooded, took off the air cleaner, nope its not flooded crank agian nothing, so i remember a few times it would not get any spark and would not start which is fustrating because its a brand new petronix h.e.i so when i got sick of it doing this i took the cap and coil of and cleaned the insides and the electrodes and it hasnt done it since til now, i checked the spark nothing, un plugged my tach wire because i thought it was getting crossed with it, cranked it nothing, this is really ghetto but i tapped on the coil and it instantly cranked, but the idle idles steadily between 700-800 too high for cold operation so i checked the linkage and backed out the screw nothing happend the idle part is bent and the screw cant go any farther back so i guess i will take the carb off and bend it back? how did the linkage idle part get bent in the first place? was it because of too hard of foot feeds?

My bad..thought I read you had a Holley 750...good luck on the fix.