No Start, Engine Cranks Okay, Troubleshooting With Basic Tools (No Power to Injectors)

In this video I will show you how to test for spark, fuel pressure and injector pulse as well as how to test the engine main relay for proper operation. The vehicle is a 2005 Chevy Equinox with a 3.4L engine and the main relay (which supplies power to the fuel injectors) is not turning on.

Engine Performance Diagnostics chapter 3


  • engine cranks normally but will not start


  • repaired damaged wire going to the engine main relay

Tests shown

  • how to test for spark and injector control using a test light
  • how to test fuel pressure
  • how to test the engine main relay
  • how to test a computer driver
  • how to locate an open wire in a harness
  • how to repair a broken wire
  • how to test a relay