just got off tbi to carb, installed new heads,carb w/regulator,vac adv dist, and cam (.470 lift 215 duration) nothing to radical. problem is car will only start and run with timing set at 8-10 deg advance with advance hose pulled. when I hook up the vac advance it puts timing at about 12-14 deg. with curb idle at 1500 it barely holds at 650-700 when in drive.should I need to advance the timing this much? when i try to adjust timing closer to 0 when running the car dies when I get to about 6 or 7 degrees. do i look at a possible slipped balancer or is this normal? thanks in advance
Buzzman1

 

8-12 initial timing no vacuum advance at idle is typical for non-computer carb set-ups. The bigger the cam, the more initial advance is required, typically.

12 degrees BTDC at idle no vacuum advance is a good place to start.

Sounds like you have the vacuum advance hooked up to a "ported" or "timed" vacuum port. If timing jumps significantly just off idle, then that is the case.

 

thanks five7kid

I have got the vac adv hooked up to the port on the carb that the book says to hook up for vac adv dist...glad to hear that 10-12 btdc is ok . should i have to get the motor to idle at 1500 to get drive idle at 750? I will doule check the advance hookup but at idle with the advance disconnected I would think it should hold a better idle in drive.?

 

the book refers to the port i have the advance connected to as a timed spark vacuum source...is this correct or should i have it hooked up someplace else?thanks

 

it shouldnt idle that high, idling at 700rpm should be enough.

it could be a carb problem (idling to rich)

i have the same problem with setting idle at 1500rpm to keep in drive at 500rpm, but im using a 234 duration at 106lsa (!), so im having to drill two holes in the throttle blades to improve idling.

yours should idle at 700rpm easy with that small of a cam!!!

make the vacuum advance throw in an extra 8 or 9 advance points on top of the 12 points advanced

 

thanks...I started to mess with the idle screws last night and it seemed to make a difference, I read the manual and will try to dial it in better tonight. The dist is putting about 8-10 degrees of advance on top of the 12 so I think you are right about the idle mixture screws...Ill mess with that tonight and let you know.

thanks for the input
Buzzman1