Chevrolet Repair: 2001 Silverado 5.8 l. Misses at Starting, fuel pressure regulator, silverado z71

Question
My son has an 01 Silverado Z71 with a 5.8L engine.  The problem is that it misses pretty badly when first started on a cool day.  After it warms up a bit it seems to run just fine.  
Dealerships have changed various sensors and even replace the intake manifold, thinking it was warped.  Still misses on cool days.
Any suggestions are appreciated.


Answer
Hi Claude, My first thought was the intake gasket but since they already did this thats not it.. The only other thing is the fuel pressure regulator, they will leak into the intake and cause a misfire. Remove the hose from the fuel pressure regulator and let set overnight. Start the engine in the morning to see if it is any better.


Sorry I can't help more on this one

Have a Great Day               Mark