very strange issue (fuel injectors?)
 

Hello guys, this past July I bought a 1990 300zx. I haven't had any problems with it at all up until the past few weeks. Get ready for it...

The car has been in and out of my mechanics for this same issue and he hasn't been able to figure it out. So at 8 AM this morning my car started fine and got me to work. (15 minute commute) Around 5 oclock I tried to start the car, and it just clicked and wouldn't start. It did start when my coworker tried to jump it 5 minutes later though. My mechanic and I have replaced the battery, tested the alternator - it gets power - and replaced all of the belts. He believes its the fuel injectors dripping gas onto the spark plugs causing the car not to start, but does the fact that it starts when it's jumped mean that isn't the issue?

Could it be a short somewhere? or maybe one of the relays are stuck on? Or maybe something is draining the battery?

Also, sometimes when driving it the radio will randomly turn off, the lights will dim and the anti lock light will turn on and the car will run like shit, then it will miraculously work perfectly fine again, this hasn't really happened since changing all the belts though. On the commute to work this morning the radio did turn off and on, off and on, but as soon as i turned off the headlights it stopped happening.

Too long; didn't read: The car will start fine in the morning, then around 5 it'll just click and turn but not start, but WILL start when its jumped. BRand new battery, alternator gets power, very lost. please help.

If there was a parasitic drain on the battery it would happen in the mornings also. Any time the car sat long enough to drain the battery.

With the many electrical issues you seem to be having makes me think of an alternator going bad though.

That's weird, it sounds like an alternator. How is your harness? Is it corroded? Maybe a loose connection to the alternator?