My 1994 grand marquis won't start sometimes while I turn the key all the way

Hello, without testing the various components, it is hard to say for sure why this is happening. However, this year and model did have a service repair for a starter solenoid signal wire that would intermittently cause a no crank condition. This was a very common repair, and could be the culprit in your vehicle. Other possible causes could be a transmission shift lever linkage being out of adjustment -- preventing the starting system from seeing the shift lever in the park or neutral position. You could also have an ignition switch concern. I would probably look at the items in the order I have listed them in an effort to diagnose the concern.