Got my new 454 to start right away but had a lot of trouble getting the rpms up. I had to work the carb linkage real carefully just to keep it stumbling along, when the rpms finally came up (for about 45 second to a minute) I noticed a fuel leak and there was a ton of smoke from the paint burning off the headers so I shut it down. When I let go of the carb linkage I thought the engine would idle but it didn't just shut right off. I have a brand new holley 750 with an electric choke, I was suprised to see the choke plate open a good 1/2" to 3/4" open? I thought it should be mostly closed for a cold engine, had my brother (the electrician) come over with a meter and the ground and 12 volt positive checked out fine. So my question is why didn't the rpms come up quickly and why didn't the engine idle when I let go of the linkage? I'll call Holley tomorrow but if guys can think of anything I would really appreciate it? Thanks!

check the firing order again...make sure its right...if the engine is new...new cam..
run it at 2000 rpm for 20 min. and yes its going to smoke...and you will have to set the fuel levels or at least check it ..plus set the timing..while filling the trans.. coolant...start up with atleast 8 qts of trans fluid in if the trans was new..if its a automatic???

I checked the firing order several times so I'm 100% sure its correct. When cleaning up I did notice a small vacuum port on the carb I forgot to plug. Yes it is a auto but the manufacturer said to fill it with a minimum of 4 quarts. Am I wrong on the choke thing...shouldn't it almost closed for a cold start? I'll try to get another set of hands for the next try so I can mess with the timing. Thanks rage'n rat!

I'd recommend keeping the choke open as much as possible during break-in. Too rich a mixture can wash the cylinder walls with fuel and prevent the rings from seating. Then you have excessive oil consumption and smoking which won't get better. BTDT.

Make sure the timing is set, it sounds like you don't have enough timing.

Had a similar problem when I changed carbs, it was a vacumm port that I forgot to cover. Plugged it and it ran fine.

I think you guys hit the nail on the head. When I advanced the timing it started easier and I'm really hoping that vacuum port is the missing piece to the puzzle. Going to take a half day off on Wednesday and try again, I would try tonight but I don't think my neighbors really appreciate me starting this thing with only the headers hooked up! It's really freakin loud!