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97 Blazer 4.3L Vortec - wont start in the morning I have done the basic stuff already and heres the results:
Tested fuel pressure: 51-53 lbs
changed fuel filter
added fuel injector cleaner

In the morning I'll crank it and it wont turn over, I give it like 30 seconds for the fuel pump to turn on before I turn it over and it will crank fine then wont start. I then remove the air cleaner assembly from the throttle body and manually open the throttle valve/plate for a couple of seconds, reattach the air claner tubing and then the truck fires after a couple cranks.
This is only in the morning or after siting for more then a couple hours (4-6) after that it will start up strong every time.
Im guessing that the trottle valve is stuck but I read that if I spray a cleaner down in the throttle body it will mess up the egr valve/sensor
source: automotiveforums.com