The vacuum to the vacuum advance is manifold vacuum if connected properly. That means it falls off under load. So, vacuum leaks, even small, can cause problems. Also check to see if the hot/cold air valve on the air intake duct is working properly. If there is no cold air after warm up that can cause problems. I noticed your plugs are copper - S/B silver (HR6DS), but that is probably not your problem. I would suspect a vacuum leak or the hot/cold air valve. Premium gas will probably stop the pings until you locate the problem - pinging is not good. Harold McElraft - 3354 -- In dmcnews@xxxxxxxxxxxxxxx, Jason Ferrara <jason@...> wrote: > > Well, I got myself a vacuum pump and gauge. The vacuum advance seems > to be working correctly. If I apply vacuum to the distributor while > running the engine at idle the timing follows the table in the > workshop manual. If I hook all the vacuum hoses up correctly and look > at the timing at 4000+ RPM, I see 53 degrees (13 base + 20 mechanical > + 20 vacuum). > > One thing I did notice is that if I hook the vacuum gauge to the line > that goes to the distributor, I see 0 HG at idle, and it jumps to 20 > HG as soon as the engine comes off idle, and stays around that as > RPMs increase. This would seem to imply that I'm always running with > full vacuum advance, except at idle. Is this normal? > > Spark plugs are Bosch HR6DC. I pulled the no. 6 plug, and it looks > normal. > > > > > To address comments privately to the moderating team, please address: moderators@xxxxxxxxxxx For more info on the list, tech articles, cars for sale see www.dmcnews.com To search the archives or view files, log in at http://groups.yahoo.com/group/dmcnews Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/dmcnews/ <*> To unsubscribe from this group, send an email to: dmcnews-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/