Engine Mechanical problem
2001 Saab 9-5 6 cyl Two Wheel Drive Automatic 115000 miles

my 2001 9-5 wont start after its been running for a while. it cranks but wont start. Its not the key, twice unit, or alarm issue. i know this be cause I have been through that already. Im thinking fuel relay or crank position sensor, but Im not getting a code. weird...
any thoughts out there? any help would be great.