1997 vortec 454 timing

[454ss]

what are the timing specs and is there anything out of the ordinary i need to do to set the timing after the distributor has been out ? i have never worked on these vortecs before. thanks.

[GM-Tech]

what are the timing specs  and is there anything out of the ordinary i need to do to set the timing after the distributor has been out ?

 

Oh boy, I hope you marked the distributor before taking it out. Anyway, here's the timing set procedure from our service information. Good luck if you don't have a scan tool...

 

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Setting Timing

 

Camshaft Retard Offset Test

 

The ignition timing cannot be adjusted. The distributor may need adjusting to prevent crossfire. To insure proper alignment of the distributor, perform the following:

 

With the ignition OFF, install a scan tool to the DLC.

Start the engine and bring to normal operating temperature.

 

Important

 

Cam Retard Offset reading will not be accurate below 1000 RPM

 

Increase engine speed to 1000 RPM.

Monitor the Cam Retard Offset.

If the Cam Retard indicates a value of 0° ± 2°, the distributor is properly adjusted.

If the Cam Retard does not indicate 0° ± 2°, the distributor must be adjusted.

Adjusting Camshaft Retard Offset

 

With the engine OFF, slightly loosen the distributor hold down bolt.

Important: Cam Retard Offset reading will not be accurate below 1000 RPM

 

Start the engine and raise engine speed to 1000 RPM.

Using a scan tool monitor Cam Retard Offset.

Rotate the distributor as follows:

To compensate for a negative reading, rotate the distributor in the counterclockwise direction.

To compensate for a positive reading, rotate the distributor in the clockwise direction.

Repeat step 4 until 0° ±2° is obtained.

Turn the ignition OFF.

Tighten the distributor hold-down bolt to 3N·m(25 lb. ft.).

Start the engine, raise engine speed to 1000 RPM and recheck Camshaft Retard Offset.