GM Service Manual Online
For 1990-2009 cars only

Problem

Action

Faulty governor or governor installation

  1. Test the governor for proper operation and inspect air lines to and from the governor for kinks or restrictions.
  2. Replace or repair the governor or its connecting air lines.

Faulty or worn unloader pistons or bores

  1. Inspect for worn, dirty or corroded unloader pistons and their bores.
  2. Replace as necessary.