Motor locked down?

[Shalee89]

I am looking for ideas on what to check out. My daughter has an 82 280zx. inline 6 2.8fi non turbo. Car was running rough after setting 2 weeks. Was low on gas and figured was due to crap in the tank. Put fresh gas and treatment. After a few miles it smoothed out. She told me periodically it would backfire 3 times after going into 3rd gear. I drove it no problems. Last night she p[ulled into Sonic on her way to work and shut the car off. When she tried to start it nothing happened. She says lights come on, can hear the fuel pump start. I called my husband to go help her since I couldn't get away from work. He tried jumping the starter since she had problem with that previously. Nothing so he tries turning by hand. He tells me it is locked. Could this be the timing chain? My daughter tells me it was fine when she shut it off. There had been no backfiring no rough idle. Oil and water are good. Gages (sp?) showed no indication of problem either. But my husband tells me he once had a car that he drove into a store and shut off and the chain slipped down under the crank and did the same thing. Any ideas on what else to check would be greatly appreciated. Don't think I will have time to really work with it til tyhe weekend but would like to check out all possibilities then hopefully.
Nancy

[Broke_as_****]

This board isn't very active and most of the members here have later model Zs. Zdriver.com and zcar.com both have more active forums for earlier Z generations.

That being said, if the timing chain has been in there a while and the tensioner gave out that could cause the problems you're having as your husband described.