my 94 rex-regina 940 has occasional no start, no crank conditions.

this is what i know.
1. i replaced the NSS; battery is recent, no battery terminal corrosion.
2. car starts easily when i connect starter terminal 50 to the battery.
3. when the car does start, a half second delay start typically occurs when in KPIII.
4. when in KPII, all lights and power works. no weird electrical conditions.
5. no start conditions doesn't seem related to driving or temperature.
6. after i jumped the starter, car runs fine, and after driving home, the car starts up fine.

assuming the wiring is ok, would this condition be a cylinder tumbler or a ignition switch condition, bad contacts or cylinder wearing out?

thanks!
byron golden
86 245
92 245
94 940