high idle

hello i have a b2200 weber header accel coil and when i start it goes up to like 3000 let it warm up it will go down to 2000 but thats usually the lowest it goes, sometimes tho it will idle at probably around 450-600, just wondering what you thaught it might be? i've loosened the throttle cable, checked everything i could think, the only other thing i could think of is timing? would that do it if its like a tooth off? i have it set perfectly at -10 btdc. it has a little miss and everytime i turn it off it backfires slightly. the only time it sounds right is if its way off time, am i answering my own question or do you think it could be anything else before i tear off the whole front end for what feels like the 1,000,000,000 time

10 degrees BTDC is way off.Spec is 6 degrees BTDC.That is one reason it idles too hi.It backfires cause of the hi idle and timing being off.Get it in time and see what happens.bj

You said that you're had everything off the top eh? make sure your intake is mounted properly. i have a 93 so its EFI; there is a coolant line that mounts on the intake manifold studs. It goes on the outside of the intake though. Once i pulled the intake and when i reinstalled this line was in between the block and the intake. This let more air get in and the ECU dumped more fuel into the engine giving it a higher idle.