You may have one or more wiring connections that are bad. When the engine is running well, try carefully moving the wiring harnesses under the hood back and forth, particularly those in the taped bundles that run between the engine and the body. Also check ground connections, especially those between the engine and body. It is a 2001 Chevy Malibu, I do not know how to tell if it is fuel injected or Carb. It is an automatic trans, 6 cyl. Hope that makes it easier to hep me what kind of car? what year? IS it fuel injected or carburerated? Automatic? Need more info to answer this ...