I have an 88 300zx. A couple days ago, I got out of a store and my z wouldn't start. It didn't even try to start- no engine noise, not even a click. But it had plenty of juice to turn on the headlights or power the windows. After reading some old posts on here, I was leaning heavily on the idea that there's something wrong in the clutch relay or switch that has lost connection. But then, I tried jump starting it from another car and it started right up! On latter attempts, it would start on the third turn of the key (the first and second turns still producing the dreaded silence). My battery is good (I re-charged it). So my father says that it has to be the ground connection and tells me to only link the negative cables to another car and try to jump it. No go. Am I back to a cluch switch problem and it was just coincedence that it would start when jumped? What else should I look into? On the interior of the car, the clutch petal mechanism looks to be in excellent shape, but I haven't gone under the car yet to look at the other side of it. I'm going to go clean up the ground connection and see if I can find the clutch interlock relay. Sorry this is so long; I wanted to give you all the info. Thanks for any ideas!