ok well this is not for me it is for my sitter in law dad and his 300zx will not stay runing for more thne 5min and then it will not start untill it is cold and i dont know i work on 280z not 300z

 

does it run for a little bit then start stumbling really bad and seem like it's gonna die if you don't give it gas? if i so i had that same problem, i replaces the fuel filter and it solved it.

 

he has repalce the fuel and all of the sentsor on the car

 

Did he check the MAF? He has replaced all the sensors?

 

The maf will only affect the car above ~2500 rpms

 

It can and will affect idle.

 

you might have a blown head gasket. this will take time to fix but it the car get to hoot it will shut off, and wont start back up till it is really cool again or untill you fill it up with coolent. i had this problem.

 

well wait hold on dont say its the head gasket without giving him some troubleshooting info...either you or a shop needs to do a leak test on the car...what you need to do is get a cylinder on the compression stroke, to do this take out a spark plug and plug the hole with a paper towel ( not in the damn engine just a lil in the hole) then crank the car by just barely gettin it to turn the starter...really dont just crank the car...just lil by lil...then on the compression stroke the paper towel will blow out...at this point insert a air blowing fitting to the spark plug hole and blow air into the cylinder.... k heres the info from the results of this test.... air bubbles coming from the radiators coolant = blown head gasket, air coming into the exhaust= bent or unseating exhaust valve, air coming through the intake and you have a bent or unseating intake valve....if you do get one of these results then do it again as to be sure you didnt crank it too far into the exhaust stroke...if you dont feel comfortable doing this then take it to the mechanic...im not gunna take responsiblity for someone screwin something up while doing this test...lol k good luck zya

 

my 300zx did that ****. if you pop the clutch before it dies, does it run a little longer? i'd say fuel injection?

 

ummmm fuel injection....what do you mean?????everything under the hood is fuel injection...specify some more