Shuts down
 

Okay guys so I just got my 84t. The car runs good for about 45 Seconds and than just shuts down doesn't starve for fuel or studder after it shuts down it starts right back up. Guy who had it before me had to get a key made up and it's a little haggered up could it be a security issue. Any input would be great thank you guys!

bad ignition switch is an option. otherwise need a little more info. Get your battery load tested. Be sure you have clean, tight corrosion free terminals on both ends of your battery cables. Be sure the ground (negative) cable goes to a bolt into the frame before going to the starter. grounding through the starter is not a reliable connection. Z's don't like low voltage. causes the electronics to act funny. it is possible to have enough amps to crank but not enough voltage to run the electronics. If you have one size fit all cheapo clamp on terminals they are a problem waiting to happen. Usually on a rainy night around Oh Dark Thirty.

okay so here is the down low on the battery the guy had a extra battery laying around and used amp wire to reach the negative and a cheap terminal its super haggered. so should i buy some beefy terminals and a new battery? Also where at does ground bolt to the frame?

yes go to a battery shop get a new battery and cables. I use Interstate and find them to be very reliable and last longer than warranty. The factory cables had a square copper tab crimped on the ground wire. an M8 bolt was used to attach to the frame adjacent to and slightly below the M6 bolt used for the battery hold down. If that is gone you could use a short cable to that hole and a longer one down to the starter. Next best is to run 2 (two) #10 wires from the negative terminal out to each side of the engine compartment and terminated at one of the many M6 bolts inside I got new cables made for one of my Z's for under twenty bucks. Don't use those one size fitall clampon type terminals. disaster waiting to happen.

Okay thank you very much I will try that I belive I will have to run a whole new ground beacuse he has it all kinds of messed up!

so i load tested the battery did not drop below 10 upon start and was at about 14 constantly when it was running and before it shut down the voltage did not drop at all.

It's either losing spark or fuel...

So have you tested for spark? Tested fuel pressure?

So the guy who had the car before me never had the key for it so I'm thinking he sent it to a lock smith and never had it programed to the computer. Could it cause that problem?

No. You have a 1984 car... not a 2012 car. :) These ecu's aren't "programmable" for that type of thing. The Z31 anti-theft only disables the starter, doesn't kill the car if already started.

EDIT, A good (similar) read: https://www.zdriver.com/forums/300zx...ed-help-40079/