i tried to search for this, but i'm not nearly as car savvy as i'd like to be, so i'm not even sure if i'm explaining it right. any direction on this would be great, though, as i really need my car to start working so i can go to work

at first it was massively hesitating when it was cold, sounding like it was misfiring. it'd idle low (at about 500rpms, maybe a bit less) until it warmed up completely, then it'd work fine. now when I turn it on it idles for about 5-10 seconds and dies.

 

seems like an aelectricla problem.. Uplug your battery, clean all the connectors on EFI harness. don;t miss any of them. then plug the battery back in, so now your ECU should be reset and if all your connections are clean that should knock out one of the problems wich would be hessittation. now for your Idling problem that might be timing. so try and set it to factory specs (15*) that;s all I can think of up the top of my head.


-Juanton

 

could be a fried alternator.

 

take it to a shop... online diagnostics (especially for a problem of your sort) is rarely 100% accurate

 

Run ECU check as well, it probably won't come up with anything, but u might as well just in case. and it only takes literally 5 minutes.

 

usually takes me under a minute thats how easy it is. If you cant tell I am an avid beliver of the self-diagnostics feture!!

 

my 280zxt had the exact same problems, turned out to be my MAF sensor...not sure about the 300....just threw that out there just in case, getting mine replaced today...

 

i had the same problem with my 1990 300zx i had to change the plugs... spark plugs, and then i had to reset the computer.. just to find out my timming belt jumped one tooth.. but thats the way it was when i bought the car ... my alternator is shot on my 1990 300zx so im not driving it until i get it fixed check your fuel injectors connections as the ones on the 1990 300zx are not so good and some times it acts like it wants to stay on after i turn off the key...

 

If it feels like it wants to keep running after you shut off the key then the most likely (and cheapest) cause is a dirty throttle body. Easy enough to have a shop clean it and the rest of your fuel system for you.