Our Community is 940,000 Strong. Join Us.

85 300zx running issue

10-11-2011, 11:07 AM
So my 85 nissan turbo 300zx when it starts runs rough. The lights will pulsate and a shop told me the car isn't grounded. In this video at about 1:46 as I let the car run, there is a hole in the firewall by the battery where they said a wire needs to go from there to the negative cable. This has been happening since i had the car. Once it warms up it eventually goes away. Just a few days ago it began to spark another issue. After it runs a bit, the car will start to slow down. The idle decreases like its running out of juice but if you rev it up it goes back up and continues to run for a few seconds and goes back down. When its down it sputters really bad like its trying to stay alive. This is after its run for about a minute. That is also in my video. A shop just replaced the steering rack and said it was the alternator but i unplugged the battery and the car ran the same. This means the alternator is fine right? I've been in a car with a bad alternator and all the lights dimmed and no matter what you did, the car died and did not start back up. This is not the case, you can rev the engine and give it a little life.


10-12-2011, 07:40 PM
The hole above the battery that you zoom in on at one point is for the battery hold-down bracket. If I recall correctly, the ground cable only attaches to the block and/or starter in my cars, but it won't hurt to add an additional ground since your hold down is most likely gone.

The running issue is hard to id from that video. Have you pulled codes from the ECM? There is no check engine light in the Z31, but you likely have a code or two stored in there.


10-13-2011, 12:29 AM
it sounds like you have bad wires or maybe a leaking spark someware check it in the dark for stray spark and do you have any codes those can point you in a direction iwoud start with a good tune up good luck

10-13-2011, 02:46 AM
I've disconnected the battery for now because there is like a mysterious 2 amp pull. According to your website, disconnecting the battery clears the codes. Or is that for after you get the codes from the ecu?

10-13-2011, 07:58 PM
Unhooking it clears them. They set pretty quickly once you drive the car.

Add your comment to this topic!