i have a 2002 dodge ram 1500 the truck will crank but not start. Sometimes it starts then ill turn it off and try again and it wont. i dont believe its the fuel pump because when a fuel pumps goes it doesnt usually work then doesnt work. The crank sensor doesnt seem to be the issue either as it still does start sometimes. What i have noticed is that when you put the key forward and the truck reads the amount of fuel in the tank it starts. If you put the key forward and it doesnt read the amount of fuel it wont start.

 

I assume you have the Hemi? Get a fuel pressure gauge and check pressures at the rail.

 

A bad crank case sensor will delay the start.

Mine did this after i installed a new engine. I replaced the cable leading to the starter and it started but after about 10 secs of it cranking. Changed the crank sensor and it fired up right away