8.1 starting issue

[kamccarthy]

Hello all. I'm new to this forum, but I've had my 2002 GMC 2500 HD since 2003. Bought it used with 6000 miles. Has the 8.1 L gas engine with Allison transmission. The truck now has 71000 miles and is a tank. In 2010 I replaced the crankstaft position sensor after the truck shut down while at a stop light. Replacing the crankshaft position sensor was no fun to say the least, and I'm lucky my mechanic is still on speaking terms with me. My latest issue occured last weekend. My truck started and ran great all day. I stopped to get a drink at a convenience store. When I went to start the truck 5 minutes later, nothing happpened. The starter did not click, but I could hear the relay. Three days later I went out in the middle of Hurricane Sandy and it fired up like new. I'm in the process of borrowing an OBDII scanner from a friend, but right now I'm guessing it could be the following: bad ground from starter 2. fuel pressure regulator 3. ignition switch 4. starter solenoid on the firewall. Anyone think I'm close? Any input is welcome thanks. Keith