I have a 2002 Suburban LT. Beautiful ride, rapid acceleration, everything works, only done 60K
The problem there is an intermediate starting problem, sometimes it refuses to start, turns over but won’t fire, any other time (most of the time) starts immediately, hardly cranks one turn and fires up like a race car, once it starts, it runs like clockwork never cuts out. The none starting can happen cold or hot wet or dry standing over night of just stopped to go shopping.
I’ve replaced the crank position sensor, cam position sensor, gas cap, spark plugs, battery, the ignition key is the old fashioned sort with no security chip. When I run the OBD11 it only gives P0449 Evaporative Emission Control System Vent Valve/Solenoid Circuit Malfunction and I get this even when the truck is running good, I’ve sent for a vent valve to replace but I shouldn’t think it’s that. I've had this problem for almost a year, local garage can't find the fault.
Please help this old boy in the UK if poss’ from going mad.
Gus.

 

Do a fuel pressure check when it will not start.

 

Thanks for that, I've done that already and it was 55. Also getting a spark. ;o(