Timing question

[trickyrix]

So I checked/bumped my timing this weekend, and I noticed a couple of funny things when I got the light on the pulley. First, I noticed that the timing appeared to be jumping around quite a bit - it would settle on the 10* mark, then waffle up to 12-14*, then back down to 10. Also, I saw two marks on the pulley, one of them lined up with the 10* mark, and the other was further up at around 16* or so. I used the first mark to set the timing - bumping it two hash marks to what should be 14*. The car still runs fine - no pinging on 93 octane gas, and it might pull a little harder on the top end, but I can't really tell a whole lot of difference.

[MadMerv]

So, what is your question? Did you short pin 10 to GND in the little box near the airbox? This kills the computer and will keep the timing from wandering. You won't notice much, but it will help acceleration slightly. You don't need 93 octane at 14 degrees.

[trickyrix]

So, what is your question? Did you short pin 10 to GND in the little box near the airbox? This kills the computer and will keep the timing from wandering. You won't notice much, but it will help acceleration slightly. You don't need 93 octane at 14 degrees.

Sorry... my questions would be:

1) Is it normal for the timing to wander?

2) Am I looking at the correct mark on the pulley? I assume so since the car still runs fine, but I just wanted to make sure.

Thanks for the tips... I'll play around with it a little more when I get a chance.

[CraiginTX]

+1 on jump TEN & GND to keep the computer from messing with timing.

IIRC, the 2 marks on the pulley are at 0 and +10 degrees. That is, when the engine is at TDC, one mark should be on +10, the other at 0. Advance the +10 mark to +14 and you should be good to go.

My car doesn't ping on plain 'ol regular at +14 as long as it's cool out. During the warmer months, mid-grade seems sufficient to keep the ping away.