Quote:
Originally Posted by rickjordan
Is the spec chart you are referring to called "Firing Point"? In the first column titled "Adjusting value of firing point" with out vacuum at 3000 rpm... 30. The next column is titled Test values ignition adjustments with/without vacuum at idle, 1500, and 3000.
Per this chart, the idle timing is 2 deg TDC with vacuum. At 1500, the timing is 15-19 degs without vacuum and at 3K, it's 30.
They mention to remove "both vacuum lines for adjustment". Other than the one that goes to the vacuum advance, where it the other one they are talking about?
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The first column is Adjustment value at firing point. It is hard to read their minds, but for the "standard" engine they say to adjust at 3000rpm without vacuum. For the NA the adjustment value is at idle. My guess is that in NA because of emission laws, they want to be sure of the idle setting. In Europe & ROW, they are more interested in performance. This is just my guess as to why there is a difference.
It is hard to SET timing at 3000rpm. I usually set it at TDC at about 700rpm (with vac). Then speed engine up to 3000rpm (without vac) and see how far it advances. Keep making small adjustments until you get about 27-30deg at 3000rpm.
The advance marks are to your right when looking down at the engine. It is easiest to get under car and mark the 0, 20 and 30 deg lines with chalk or paint.
Regarding vacuum, if you have just one vac line on the vacuum diaphragm, then you should block it for the 3000rpm test and have it in place for the idle test. Some cars have advance and retard - Not sure how to handle those!
BTW, while setting timing, A/C must be turned off because it turns vac retard off.