My daily driver is a 63 nova with a 283 transplant. When I start it on cold winter mornings it runs really rough. It doesn't seem like a fuel issue. Carb is edelbrock 1406 w/electric choke. It almost feels like a cylinder or two is missing or a stuck valve or timing issue. Sometimes I smell gas. The car actually bounces as the motor seems to hit and miss in a rythm. I let it warm up a bit, then I have to throttle it a few times 'till it suddenly goes away then runs like a top. I'm sure my neighbors are sick of being woken up at 6:45 every morning, not to mention my wife and daughter. Anyone else ever have this problem or have any suggestions?
Tell your neighbors to consider themselves lucky, I wake mine up at 4am mon-fri. haha I know you don't think the carb is the problem but thats what I would check first. If you're smelling gas and it smoothes out when you throttle it, the choke might be acting up.
Manifold heat passage open ? Heat riser still working ? Fast idle cam linkage intact ? Plug heat range too cold ?
It only happens in winter months when it's in the 40's or lower. The choke seems to be working fine. It seems like I have to get the rpm's up pretty high, then someting suddenly frees up. I had another old Chevy with a 194 straight 6 that did the same thing. I never did figure it out.
It doesn't seem like it's a warm up issue as much as it seems like something is sticking when it sits over night in the cold. When I start it up cold, I can rev it up high immediatly and get it to stop without warming it up. I just like to warm it up a bit before I rev it like that.
Don't remember the carb numbers but, isn't the 1406 a 600 cfm?? If it is , it has larger primary jets than you want I think. Pick up a 8.00 set of step up springs and go to a shorter spring. I f the car runs alittle rich now when it's warm, part of that could be the springs. You can also shorten the accel. pump shot by putting the rod in the bottom hole on the linkage. It sounds like you need to lean the mixture out . my .02
Mite be sticky lifter or lifters. Just for the hell of it next time before you change oil pour a quart of trans fluid in and let it idle for a hour or so. Then drain it good and change oil. The high detergent in the trans fluid will loosen up sticky lifters and clean sludge up to. JC
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