My 1977 Datsun 280z, Why wont it run?

[tma1488]

I Start it and drive it a small distance( 3 or 4 city blocks ) then it just cuts out, and i get nothing, it wont even turn over for about 2 or 3 hours later. Why does it do this?

Car Specs:
1977 Datsun 280z
Straight 6
Fuel Injected
Just replaced the Alternator
Brand New Battery
been sitting for 6 to 8 months, unitl recently when i replaced the above mentioned parts.

I think it might be the radiator not working, it seemd to have something growing out of it, but that could be nothing. Would a bad radiator cause something like this?
Ok, i now think it isnt the radiator, because i messed with some fuse's and then it would turn on, work for a few then cut out again. Then i mess with some fuse and it turns on again. What the heck is wrong with my car?

 

[Sharp Marble]

it's old and it's tired. it wants to retire.

 

[ivy_trick_mess]

Definitely get your radiator checked if something was growing out of it...you need water to cool your engine...try taking it for a tune up as well...or have a mechanic check it out...they usually will do so for a small fee
Good luck!