2001 chevy blazer 4.3 2 wheel drive hard starting problem?

[Mike]

I have a chevy blazer a month ago I started having a hard starting problem when the blazer sits it turns over for 10 to 15 seconds before it will start once it starts it had multiple miss fires in all cylinders checked on a data stream computer if I shut it off and restart it starts right up only when i leave it for 5 minutes or longer will it start hard has plenty of power and pickup but idles a little ruff .had an evap leak and fixed that have no codes in the computer .I have replaced the plugs ,wires,coil,pick up coil,cap and rotor,and also the ignition module,the fuel pump has 64psi any ideas would be a great help .Also checked all the fuses and relays they seem fine. thanks Mike