Hi All, I'm normally pretty good at searching threads to figure out the issues of my car but I gotta say this one is stumping me so some ideas would help. Please forgive the long post

Car:
2004 350z Enthusiast 6MT
Stock engine 157,000 Miles driven daily

Symptoms.
- Engine dies randomly.
- Car surges and bucks in WOT. Revs start to go crazy a second before theres any actual surge, which is weird.
- Radio or gague cluster lights or anything plugged into the power outlet or any comination of these will shut off for a few seconds and then turn back on.

Details: The radio and lights issue started about 9 months ago. Didn't happen too often so I didn't really think anything of it. Recently it has been increasing in occurrence so I'm guessing it's possibly related.

The engine dying issue began about 4 months ago where it would randomly die maybe once a month but has steadily been increasing in occurence to where it currently shuts off randomly about twice a day. There is no pattern to where or when it will die. Usually I'll just coast somewhere safe, wait 2 minutes and it will fire up again and I'll continue about my business. There are no CEL codes stored. From research I concluded it was possibly the cam sensors or crank sensors so I replaced them all a week ago. The engine still dies. 2 days ago the car started to have sporadic instances where it would buck and surge wildly in WOT a few times a day but the rest of the day it would drive fine. The tach starts to go crazy a second before it happens. Sometimes I'll get a light misfire but the revs will drop 2000rpm which feels inaccurate. My next guess was my fuel pump was dying a slow death so I replaced it with a walbro pump this afternoon but the problem is still there. Visually and physically checked the all of the grounds I could see and everything seems tight. I'm pretty stumped as what to try next. Being that the problem is so intermittent I'm having trouble being able to diagnose anything.

The tach going crazy leads to my next guess that its the ECU but thats a total shot in the dark. Again, no CEL and my code reader hooks up to it just fine. Any help appreciated.


tl;dr
Replaced Crankshaft and camshaft sensors, no luck; Replaced fuel pump, no luck; checked grounds, no luck; ECU next???

 

The fact everything turns off is weird is kinda sounds like u have a grounding issue or power to ground issue.

 

Sounds like you're having intermittent current loss.. How much time is on your alternator and battery? Are the terminals clean and the clamps tight? Take it to a reputable parts store and have your charging system tested.. I feel like a broken record with this one, but have you checked your IPDM for corrosion? Could've gotten water in it 9 months ago, terminals got a little corrosion on them, water evaporated, but corrosion stayed. Just a possibility, so I'd open that up and check that too.

 

Thanks for the replies. I checked all the grounds I could and took a can of electrical cleaner to every harness I could find including the ECU and BCM. I didnt really see any corrosion but I figured it couldn't hurt. I also heard from someone that non-nissan crank shaft sensors cause the surging at WOT so I replaced that as well. I drove it all day today and everything was normal so I'm hoping whatever I did fixed it. I'll update if it didn't