QUOTE(Cap'n Krusty @ Aug 4 2007, 03:21 PM)
Ferpetessake! Why do you think it has a vacuum retard? It's SUPPOSED to run somewhat retarded at idle, and instantly release as the throttle plate opens.
Here's the technique, just as they taught it at the P-car school in 1973/74:
Set the dwell to 47 +/- 3 degrees, warm the engine to running temperature.
Unplug BOTH vacuum hoses and plug'em up. A couple of golf tees work fine.
Using the air bleed screw on the TB, lower the idle to 800 RPM.
Set the timing to the 7.5 degrees BTDC mark.
Reconnect both hoses and use the air bleed screw to adjust the RPM to 800-900 RPM. Once it's warmed back up and the idle has stabilized, fine tune the idle speed.
THAT'S the way it's done. If the vacuum capsule doesn't function properly, you'll need to replace it. They're NLA, but good used ones are out there.
The Cap'n
10-4, Cap'n. This is just a sanity check -- I wasn't sure that Porsche would design the ignition system to fire AFTER TDC, even under idle conditions. Thanks for verifying this.