View Full Version : Timing - Big Difference Between 10 & 12?

09-14-2004, 03:42 PM
On my 88', the timing is supposed to be 10 degrees BTDC. Because I didn't have a light, I took it to the service station a block away and had him hook up his light. It came out to be 12 degrees BTDC. He said that was fine, and didn't adjust it.

Should I move my cap to make it 10, and if so which way do I move it, and approximateley how much? Thanks to everyone who consistently provides answers to my questions, you've saved me thousands.


09-14-2004, 04:54 PM
12 should be fine. To answer the ? of how much, not to oversimplify, but it should be rotated 2 degrees. I don't think I would bother if you don't have a timing light. You would never know if it was right if you don't use one.

And, no, I don't want to hear from anyone who says they just listen to it to adjust the timing. That's guessing. If it ends up at the right amount of advance, it's a coincidence unless thay can do it dead nuts on every time.

09-14-2004, 09:19 PM
JimN, As the points wear what impact does it have on timing and dwell? Is it measurable? I have heard people say time it so the timing is a little early (or late I can't remember which) and the dwell is a little low (or high) because it will come to you as the points wear.

I generally change the points well before they are worn so I try to line both up with the factory specs when adjusting but wanted to hear your comment on this.

OBTW... Lets not start the points vs. electronic ignition upgrade debate on this thread again. I am happy with points for now and will probably be for some time to come.


09-14-2004, 10:05 PM
If you're going to check/adjust the timing, you may as well reset the dwell. It doesn't take very long and it'll just run that much better if it's kept accurate. The dwell can be set with the cap off, by the way. Points aren't my favorite, but I don't have a problem with them as long as they're not neglected. Lube the little wedge that rides on the distributor cam and they should last quite a while. If my feeble memory serves me, the dwell should be between 26 and 34 degrees. As the wedge wears and the points burn (then are filed, etc), the dwell decreases and the spark intensity drops off. The timing doesn't change unless the distributor rotates.

09-15-2004, 12:38 AM
For my 87 Prostar with 351 the manual says set dwell at 31.