setting distributor timing

[alex]

so, for a 1993 gmc 1500 sierra. to time it. i need to get cylinder one to top dead center and then my distributor to point directly at the cylinder 1 contact inside the distributor cap, correct?

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[Mike]

In another thread, you said that you’ve just replaced the distributor….
You have to find top dead center for cylinder #1, the timing mark on the harmonic balancer to read 0 degrees AND the rotor to point to the #1 contact in the distributor.
This thread has helpful links
https://www.ericthecarguy.com/kunena/8-Service-and-Repair-Questions-Answered-Here/58908-best-method-to-find-tdc

[Todd Smith]

Just to add to the discussion if anyone else comes across this, I’ll share the quick and easy method we were taught in auto school called the bump method.
1. Unplug the ignition coil(s) if you haven’t already.
2. Pull the #1 plug, on a SBC it should be the forward one on the driver’s side.
3. Place your finger over the plug hole as to cover the hole completely.
4. Have someone “bump” the motor. Split second key to START position, not cranking away like you’re trying to get it started. Just one crank revolution.
5. Repeat this method as necessary, telling them to bump the motor, until the compression blows your finger off of the hole. (this is very light and doesn’t hurt)
6. Rotate the engine counter-clockwise back to the nearest 0 timing mark on the crank as you probably overshot it by an inch or so.
7. Install your distributor with the rotor button pointed at #1 on the cap.
8. Install everything and fire it up and set your base timing.
9. Crack open a beer, you’ve earned it.

[Author]

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