The engineers came up with 5 Deg BTDC as the best all around setting for timing taking into consideration the fuel quality, the operating temps of the engine and the strain on the starting system. Timing more in either direction will sacrifice these operations. If you are running 89 to 100 octane gas you can do just fine with 7 to 10 BTDC. Just set it there.
Adjusting to peak vacuum addresses top end performance only and ignores the fuel quantity, the engine temps and the strain on the starter system.
Yes, I adjusted to max vacuum and backed off a little. When I did this, my "miss" or "skip"came back. After a 10 mile drive, I noticed no improvement in performance, so I adjusted the timing until the "miss" went away again - and I still had the same max vacuum!
At that time (still hot), I tested the coil to get my hot readings - .67 and 16,200. Cold was .62 and 15,060.
When I went for another test drive later, she didn't want to start. This time I held the throttle on the floor while cranking and she started up (albeit with a little smoke).
I noticed that if I let her idle for about 5 minutes she will start to stumble. If I catch it in time and rev her up, she will run another couple of minutes before she stumbles again. If she dies, you have to hold the throttle to the floor to get her to start back up. If you kill the ignition switch, she will start with no problem (usually).
I was thinking it was an electrical problem, but now I believe I have a fuel problem.
I will put the pressure test on my list for next week when I get off of work again - I'll have to work out the hookup of the gauge. I'm out of time this week.
