What is the ignition timing procedure for a 1998 Chevy truck?

You can't adjust the ignition timing on a 1998 Chevy truck in the same way you would on older, carbureted vehicles. 1998 Chevy trucks use an electronic ignition system controlled by the PCM (Powertrain Control Module). There's no distributor to advance or retard. The PCM constantly monitors various engine sensors (like crankshaft position, throttle position, oxygen sensor, etc.) and adjusts the ignition timing accordingly for optimal performance and emissions.

Therefore, there's no "ignition timing procedure" in the traditional sense. Trying to adjust it yourself will likely damage the system.

If you suspect a problem with your ignition timing, you shouldn't try to adjust it. Instead, you should:

1. Check for diagnostic trouble codes (DTCs). Use an OBD-II scanner to retrieve any codes stored in the PCM. These codes can pinpoint potential problems with sensors or other components that might affect timing.

2. Have a professional diagnose the issue. A qualified mechanic can use advanced diagnostic equipment to pinpoint the problem. Issues that *might* appear as a timing problem could actually be caused by faulty sensors (e.g., crankshaft position sensor, camshaft position sensor), a failing PCM, or other electrical problems.

3. Don't attempt to bypass or modify the PCM. Doing so will almost certainly cause damage and could make the vehicle un-drivable.

In short, the "procedure" is to take your truck to a mechanic if you have a concern about its performance. Attempting to adjust the "timing" yourself will likely result in wasted time and potential damage to your vehicle.