Timing....

[Sejo]

What does it take to set the timing the our Tahoes? I drive a '99.

Mechanic told me that the timing was 6-degrees retarded; what are some of the side effects of the truck running this way? What are the ways of adjusting the timing - is a new timing chain the only answer?

 

[Sepiroth]

To my knowledge, there is no way to time a stock engine in that year of Tahoe. The distributor is correctly installed one way. Now when installed it could be a tooth off however, that will throw a code.

How does your mechanic know the timing is 6* off?

 

[mygreen98]

timming must be set with a scanner. it needs to be at zero degrees + or - 1 degree.

 

[mygreen98]

Avatar
Below is the text from GM Service manual for 1997 Chevrolet C Pickup 5.0L, 5.7L, and 7.4L
Accordind to this you don't set the timing but the timing offset.
You need a "Scan Tool" that plugs into the truck and can read the data from the trucks computer.
Besides from that, it looks like a normal timing procedure.
You might be able to borrow a scan tool from a parts store, or at least use their tool and do it in their parking lot.

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.

 

[Sejo]

To my knowledge, there is no way to time a stock engine in that year of Tahoe. The distributor is correctly installed one way. Now when installed it could be a tooth off however, that will throw a code.

How does your mechanic know the timing is 6* off?

He had this MACHINE: LINK

 

[Sepiroth]

In thats case, Mygreen98 gave you the procedure.

 

[redhat-z]

Cheap timing fix.

My 98 Yukon needed to be tweaked a little after removing intake manifold to replace intake gaskets. It was pinging under load. I bought the $90 ODBII scan tool from Harbor Freight. It was giving me a "Spark Misfire" error I believe. All I did was barely turn the dizzy, read code, clear code, and repeat until code disappeared. Runs great now.

 

[anunez]

thanks I think this will help me just finished replacing the intake and head gaskets on 99 Tahoe, getting a P1345 reading on scaner. This should fix that. Thanks again.