My '99 5.9L had the exact same symptoms about a year ago. It was working fine, and then it just wouldn't start. At first, it would kick a few times, but never run. Then after I kept trying, it wouldn't even kick over.

During my debug, I pulled a plug, grounded the tip, checked for spark, and got one. So, I figured the coil/rotor/distributor/wires were probably in good shape.

I cannot remember what led me to it, but after some more troubleshooting, I decided to replace the coil anyway, and voila, the truck worked perfectly... So, what I thought was an acceptable spark must have been a weak one...

 

today i pulled #1 plug and checked position of rotor @ tdc and timming was dead on and I even had fuel on my finger so the fuel is there I just don't know what else to do even though there is spark may be coil is bad but don't understand why i have spark if this is true. would i have spark if crank sensor is bad ? also do anyone have link of picture of crankshaft timing mark @ tdc ? thanks to all in advance.