I turn the key it tries to start, rpm 200-400 then dies. turn key to start rpm 300-600 then dies. turn key to start and then starts.
test the idle air control valve and the throttle position sensor.
also, scan for codes
Thanks Mike I will try that.
Looking for a Used Sierra 1500 in your area?
CarGurus has 59,331 nationwide Sierra 1500 listings starting at $1,980.
Search GMC Sierra 1500 Questions
GMC Sierra 1500 Experts