Thanks Paul,
The car is not Cal. so no pump. Looks like I have more test to do.. I have done some spraying around the intake but not found any leaks. It's not just backfires... it runs rough with the vacuum advance above idle. Like it is loading up (engine shakes).
I just don't see that much advance on my 235 (Impala).I will check the 235 again tonight. The dist on it rotates with the vacuum advance.... so you can see it and verify it is functioning. On the 230 (Nova) the diaphram is connected to the point plate.
So lets say at 2000 RPM you could have 15 deg of Centrifugal plus 10 deg of vacuum advance... so 25 degrees advance total?
Thanks, Clyde
