Mystery Problem 96 GMC Sierra

[MojoGator]

I'm stumped I have a 96 with 5.0 Vortec 135k miles has always ran like a champ a week ago it would turn over but not fire checked my fuel pump pressure it was 64 at the rail checked spark it was good but the dam thing just wouldnt fire waited a day which happened to be real warm went out turned the key ans sure enough it fires up I have taken it to a shop had it gone thru and put on the computer and nothing but it still does this every so many days

 

Anyone have any ideas

[Dirtautoguy]

Well you didn't say you checked for air? Maybe check the filter and hoses for the intake. A motor has to have three main things to run fuel,spark,and air. Should be a pretty simple check pull the filter and look in the throttle body and see if it will start without the filter on. Also if the throttle body has a small hole in the plate see if its plugged up. good luck