Kspinazzola

Well I’ll try to make a long story as short as I can. I have an 06 350z manual that I swapped to a nonrevup motor. Car ran perfect in every way after the swap but I never registered and put on the road since my work life got busy as hell.

A year later I’m ready to register so I wanna get her back to 100%. I let her run and warm up every once in a while over that time.

she got a coolant flush, new battery of course, and was leaking oil from the left side VTC solenoid so I replaced it and the gasket and changed the oil. (Solenoid installed was used off a 04 G35 sedan with non revup engine)

let her run after and she idled fine but I didn’t run it.
now today 1 day later I go to drive her a bit and she loses power and bogs down under any load.
throttle also has a very slight hesitation when I hit the gas that wasn’t there before.

Scanned codes and got a P0603 which I assume is due to the completely dead battery that was in it. Doubt it’s related to my issue.

could the new VTC solenoid be the cause of this? Possibly got a bad one causing timing or ignition issues?

Any other possible causes for this issue? Like I said the car unfortunately sat for about a year but does have a very very low mileage engine in it with tons of new parts. She ran like she was brand new when the swap was finished.

I think the likely culprit would be the new VTC solenoid. The one I got looked to be in good shape but I could be wrong I guess.
any help or insight is appreciated. I really don’t want any major problems with this thing after I put so much into her already, especially now that I’m finally ready to register and drive her 😂😭

icer5160

iTrader: (4)

When you initially did the swap, I assume you transferred over the engine wiring harness and ECM meant for a non-revup? A bad solenoid could be the issue, but the waters have been muddied a bit with a non-revup engine swapped into a revup chassis. The P0603 could simply be a dead battery, but it could also be a bad ECM (or mismatched ECM perhaps?). Found this post about it. With the powers of deductive reasoning and assuming the ECM issue doesn't have a part to play here, then I would suggest throwing the original VTC solenoid back in there (Try and recreate the original working condition) and replace the battery to rule that out. It's a bummer because you may need to purchase another gasket.

Also, where did you leave the vehicle parked for a year? I'm asking in case there's the possibility of rodent damage. I see you live in MA, and rodents getting cozy in stored/garaged cars, chewing up wiring, isn't uncommon in winter months. Typically rodent damage leads to a slurry of codes being thrown, making this scenario seem unlikely, but still worth a close look at the engine bay wiring to be safe.
Good Luck!
-Icer

Kspinazzola

Car sat in the driveway but no rodent damage. They all went after my celica GTS 😭😂 luckily no damage there either that I’ve found. I’d say ECM code is probably from battery. The one in there was extremely dead. I’m gonna try your idea of throwing in the old solenoid to isolate the issue. Luckily enough I accidentally ordered 2 gaskets for the solenoid when I bought parts.
I hope throwing in the old cracked solenoid will fix my issue.
i am running a revup harness and ecu on my nonrevup swapped engine, and it was running perfect when completed so I would be surprised if the ecu is bad but we’ll see I guess.

icer5160

iTrader: (4)

I'm still leaning towards the ECU as the main culprit. It's not "bad" it's just that the Revup ECU is expecting additional sensor input data from extra cam sensors/phasers since that variant supported variable valve timing for both intake and exhaust, while the non-revup only supported VVT on the intake side. At a very basic level, if the ECU isn't getting that sensory input, then it's going to give bad ignition system output (or believe there's a major timing fault and put the car in limp mode). I would suggest either swapping the ECU & Engine Wire harness with a non-revup set or look into getting it re-flashed with a non-revup ROM. There's so many wrecked Zs out there, finding a compatible ECU and wire harness shouldn't be difficult. If you can get it to work without doing this, then kudos to you!
Cheers!
-Icer

Kspinazzola

I doubt it’s the ECU at least not what you suggested. I shoulda explained, with the non revup swap the car runs on a non revup ECU, so the ECU is not actually expecting an input for exhaust cam phasing, and the connectors just remain unplugged.

I actually learned that the car was not bogging under load as bad as I thought. I fixed the overheating issue I was having on the car so I was able to go out for a longer test drive, and it seems the bogging is much less than I thought.
it seems to just not like accelerating when under 2k rpms or so, but it’s weird. It’s intermittent,

I took it for some longer drives and figured out that the car (sometimes not every time) seems to run slightly rough when it first starts up, but goes away very quickly once driving. As long as the engine isn’t shut off it runs perfect. Once it’s shut off for more than a minute or 2 and restarted it’s (sometimes) slightly rough again, then fine once driving. At first I thought it was rough whenever colder than operating temp but it seems that even when restarted hot it will do it.
when I get that rough running is when it will bog out on me at low rpms, but goes away very quickly once moving.
Seems to me like something causing a misfire but of course it won’t throw any codes lol.