02 Silverado starting issues

I've got a 2002 silverado 1500 that won't start until the gear selector is run through the gears then it starts up just fine. Any Ideas are greatly appreciated.  

change the transmission range sensor...   its like a neutral safety switch on the side of the transmission...

not cheep.. but important..    

there are multiple circuits in it...  

it changes the voltage returned to the computer to let the computer know what position the shift lever is in.. so it knows what to do with the shift sequencing...  

you might try adjusting the shift linkage...    but if your truck has over about 70K miles.. or has been through deep water.. it might have been damaged... its normally water proof...   you might have to heat the connector opening slightly with a mini torch.. to get the sealant soft enough to unplug  the harness.

you should also be able to start the engine in neutral.....