[1981Zapper]

i was thinking if i buy a new Adjustable HEI Vacuum Advance canister and a advanced curve kit and put it in, would this fix the problem?

 

[Steptoe]

Could do..If the VA is a post '72 ported vac unit and is all in above idle vac, it could give your symptoms, if connected incorrect.
Pre and post '72 smog dizzys have quite different configurations espec if have a bigger cam.
The best idea would be to sort the specs of the VA,

 

[1981Zapper]

Could do..If the VA is a post '72 ported vac unit and is all in above idle vac, it could give your symptoms, if connected incorrect.
Pre and post '72 smog dizzys have quite different configurations espec if have a bigger cam.
The best idea would be to sort the specs of the VA,

Here is a Adjustable HEI Vacuum Advance canister for a 1975-81 Distributor,
http://www.jegs.com/i/Moroso/710/72315/10002/-1?parentProductId=764382

The cam in the car is pretty radical, here is a video
1981 Camaro Z28 HYPO - Video

 

[gingerbreadman1977]

i would say you dont have enough initial timing. you said you have a total of 32 but if your running a roudy cam you would want at least 18 of that 32 to be initial. if your running a modest cam then a minimum of 12 would be sufficient.

increasing initial timing increases idle speed which in turn means your throttle blades can be at closed idle position therefore no run on at switch off.

so i guess my question is whats your initial timing and does it suit your cam ?

 

[1981Zapper]

i would say you dont have enough initial timing. you said you have a total of 32 but if your running a roudy cam you would want at least 18 of that 32 to be initial. if your running a modest cam then a minimum of 12 would be sufficient.

increasing initial timing increases idle speed which in turn means your throttle blades can be at closed idle position therefore no run on at switch off.

so i guess my question is whats your initial timing and does it suit your cam ?

i Had to change the Harmonic balancer and i had a New spare balancer but was from a 305 with the timing tab at 12:00 so I made a new top dead center by lining up the crank key straight up and making that 10* BTDC, its currently at about 5* initial timing but I think the line I made up is a few degrees off, and the total timing is around 27*. i had the inital timing at 8* and there was pinging, so i lowered it to 5* and it stoped