Confused About Setting Timing Please Help...

[BMAN]

I'm not to sure what I need to do at this point. I removed the distributor cap and lined up the rotor with the notch on the casing and looked at the drive pulley to make sure the marks lined up and they did perfectly. I put a drop of finger nail polish on the TDC mark. My 930 doesn't have any letters stamped on the pulley just the marks.

I then drove it around to warm up the engine, I set the idle at 900 RPM and then set my timing light to 0 and the TDC mark lined up with the fan shroud.

Now my question, with my light set at 0 shouldn't the timing mark to the right which should be 10 degree's be lined up with shroud? Not the TDC mark? If I set my light to 10 degree's the marks move to the right and doesn't line up?

With my light set at 0 the 10 degree's mark should be lined up with the shroud and if I set it to 10 degree's the TDC mark should line up with the shroud? I'm I right?

[BMAN]

Thanks for the reply... My light does let me advance to any degree. On my deck lid it states 10 degree's at idle and 26 degree's at 4K RPM. If I advance my light to 10 degree's shouldn't the TDC mark line up at the shroud?

[911pcars]

It sounds like you have a timing light with an adjustable advance control knob.

To set static timing at idle, adjust the knob so it doesn't have any affect on the timing; (usually fully counterclockwise). Start engine, run at idle speed, then point the light at the pulley/crankcase mark area. Confirm the 10º mark on the pulley (or whatever the timing spec) aligns with the split in the crankcase. If not, loosen the distributor hold down bolt, then rotate the distributor CW or CCW so the correct mark lines up with the split in the crankcase.

To be more accurate, raise the engine speed to 5000 rpm, then confirm the factory spec timing is correct for 5000 rpm. If it's not correct, adjust it accordingly and let the static timing be where it be. Be aware advance/retard weights need periodic lubrication and sometimes stick if in need.

Timing lights with an adjustment knob provide a convenient method to read the ignition timing off of a display built into the timing light instead of tracking the pulley mark. To observe the timing at a selected engine speed, rotate the knob until the TDC mark on the pulley is opposite the crankcase split, then read the ignition timing directly on the display.

Hope this helps,
Sherwood

[snbush67]

I understand now... So, to answer your questions...


Now my question, with my light set at 0 shouldn't the timing mark to the right which should be 10 degree's be lined up with shroud?

YES, AT IDLE

Not the TDC mark?

CORRECT

If I set my light to 10 degree's the marks move to the right and doesn't line up?

YOU MAY HAVE TO ADJUST THE DISTRIBUTOR BY TURNING IT SO THAT THE MARKS LINE UP WHILE THE RPMS ARE AT 900.

YOU CAN MAKE ANOTHER MARK AT 26 DEGREES ON THE PULLY AND CHECK IT AT 4K.


With my light set at 0 the 10 degree's mark should be lined up with the shroud

ONLY AT IDLE

and if I set it to 10 degree's the TDC mark should line up with the shroud?

CORRECT AT IDLE

I'm I right?

YES

[BMAN]

You see that's my problem, when my light is set at 0 it should line up at the 10 degree mark at idle which it doesn't. And if I set the light to 10 degree's it should be at the TDC mark which it isn't. I guess I need to move the distributor around.

[snbush67]

Correct, you may also have to adjust your idle and fuel mixture, but you may want to seek further guidance from a local shop.

[herman maire]

Here is what I did.

For my 73 the spec is 10deg ATDC at idle, so with the timing light set at zero ( its not adjustable) and the 10deg ATDC marked out I moved the distributor so that the pully mark lign up with the mark on the fan housing.

thanta how I got my 10ged ATDC

Hope its right.

[snbush67]

Yes, that sounds right. Is it running better?