Car rough idles, replaced PCV/Fuel Filter/Air Filter/Plugs. Car is automatic.

It also acts like the battery is dead then fires right up! Passed California Smog with fantastic numbers.....

Any ideas?

did you check that you are getting spark on all six cylinders? maybe replace the dizzy cap, rotor, and wires. once you have done that, check the valve clearance , 10 thousands intake, 12 thousands exaust, Hot. Once you've done that then check you timing. as far as the battery goes... It could be dieing... once the engine starts the car runs on the altinator, it will run great as long as the altinator is good.

what part of california do you live in?

good luck, Matt

Have you done a vacuum check recently? FI Z's are notorious for developing idling quirks when vacuum leaks are involved.

Starter was bad fixed the starting issue replacing that. Installed correct battery,new plugs, fuel/air filters. Starts right up.

NOW when a load is placed on the battery like brake lights/fan etc.. while driving the radio goes out. Any ideas?

make sure the battery grounds are clean and tight. Make sure nothings corroded and chassis grounding points are not rusted.

Sanded and cleaned everything I remembered. Car is in California and was garaged for most of it's life. Pretty clean.

If you have a good ground, then it might be the altinator. I had the 72 40 amp altinator and it wouldn't provide enough "juice" for my Z with all the new electrical stuff. The lights would dim and the idle would suck. I went through 3 altinators before I did the upgrade to the 60 amp ZX altinator. the Car has plenty of juice now. Just a thought.

I second the alternator idea.

Though if you don't feel like doing a ZX alt. upgrade (there isn't exactly a kit for the FI Z's) you could simply have it checked out. Cheap replacement alternator from CSK Auto is only about 40 dollars. This significantly helped my charging/electrical issues. It also provides a good amount of power IMO... but I'm not running anything ridiculous yet... like subs or tons of audio goodies... which I will eventually, so we'll see.