OK. So I have a 2008 350z with the hr motor. When driving it I get no codes. But if I stop and go into the store for 5 minutes or in the house for an hour, I'll go back out and crank up the car but it won't actually start. I have to turn the key a second time to get it to start and then it'll throw the code p0014. Clear the code and drive forever and no codes will return until I go to crank it again.
Things I've tried:
Replace exhaust side cam sensor bank 1.
Replace vvt solenoid on bank 1.
Replaced spark plugs.
Ran an oil flush and oil change.
Checked all wires plugging to the above sensors.
Cleaned throttle bodies.
Cleaned mass air flow sensors.
Replaced crank sensor.

Add on:
Weapon R Secret Intake with Ram induction.
Hks resonated cat back exhaust.

No matter how many times I clear this code, it comes back only after cranking.
Car drives superbly and has no loss of power. No limp mode. Nothing!
Only thing is if I don't clear the code,I get crappy gas mileage. Crappier than the car already gets!
If someone can help, I would appreciate it because I've search the internet and every forum possible for this exact problem. They all come close but not exactly. Most have limp mode or loss of power, but not mine.

 

Cntrl + alt + del

 

Could be another one of the cam sensors, but could also just be due to timing chain wear (a.k.a. stretching). Some other things that could cause this...
Flywheel improperly installed.
Crank position sensor.

What's the mileage of the vehicle?
-Icer

 

But if it was timing chain stretch, wouldn't it cause the code while driving especially if I romp on it?

 

Most likely. You would need a scanner that can capture live data to see what the parameters are when the code is thrown. Since you mentioned this happens immediately after cranking over the engine, logic would point to a sensor. Have you checked the continuity of the wiring to the cam sensors and vvt solenoid? Also are you using OEM sensors?
-Icer

 

Only one sensor has been replaced on the exhaust side which is the cam sensor on top. It was from an auto parts store. I have switched the top and bottom and even from the intake side and still get the same code. All the cam sensors are the same part number so don't won't to waist money if that's not my problem. Continuity to vvt solenoid is good because I replaced that on the exhaust side due to a stumble I had when acceleration from a stop position. I don't have the stumble anymore and it doesn't act like it's going to die when I leave a stop sign or light. I had my mechanic put it on his computer and everything seems to be working. I am lost for ideas because I really don't feel like dropping $500 on a vct cover of I don't have to.

 

There's some good information I found here. Just a few other things you can try before dropping big bucks on a vct cover. Your best bet is to find a mechanic with experience troubleshooting VQs.
-Icer

 

I'll try the fuel injector in the oil trick because when I took out the vvt solenoid from the intake side, it was darker than the new oil in the pan and the oil on the exhaust vvt solenoid. Maybe it's just clogged up. Thanks! I'll keep you posted when this is done and outcome results. Will try it this weekend.

 

I feel nausea when reading problems you describe. There can be so many causes, and tracking this down can be expensive and frustrating. I really hope you get the fix quickly and easily.

 

Sorry typing from phone while I'm at work.

 

Hey Havoc,

I recommend BG EPR (P/N: 109) if you plan on trying the flushing trick. Follow up with some BG MOA when you fill up with fresh oil (Note: BG products are available on Amazon now). I'm not sure what the mileage on your Z is or how often oil changes were done. But sludge can and does cause VVT issues. My buddy's Acura RSX needed a new solenoid and some other VTEC related component to be replaced thanks to pro-longed oil changes and high mileage. Luckily those parts were cheap and easy to access/replace. Codes never came back. I just hope you don't need to replace the intake cam sprocket or vct cover.
-Icer

 

Thanks! I'll try that and post results.

 

Hey Havoc,

Just another thought. How's your oil pressure looking? Has it been reading low since this issue started? I ask because you have an HR equipped Z and these can suffer from an oil gallery gasket (inside the timing case) failure. It's a common enough problem that Nissan revised the gallery gaskets. Usually high mileage VQ35HRs and VQ37VHRs suffer from this issue. My logic behind this is that lower oil pressure could lead to the VVT system not functioning properly. I don't think this is your issue since you would/should be seeing other codes being thrown, but better to be sure. I would consider this a worst case scenario as the amount of labor/work involved in replacing these gaskets is extensive and should not be attempted by the mechanically inexperienced.
-Icer

 

I'll keep that in mind but my oil pressure has been fine. Of course, like any of the zeds I've owned, it dips when stopped but returns to normal when I apply the throttle. Oil always stays clean and I never go over on the oil change. I read somewhere that it could actually be the vvt solenoid on the intake side acting up and causing the exhaust side to compensate. That could be the reason the why the oil was a little darker on the vvt solenoid from the intake side. What do you think?

 

Good to know about the oil pressure. If my memory serves, typical idle pressure with the engine warmed up should be around 20psi-30psi and about 60-65psi when cruising on the highway (65mph in 6th gear). My cold start pressure has been around 90 psi.

Regarding the intake side vvt solenoid, it's certainly possible, but this is where a live data scanner & recorder would come in handy. You will need to check and compare duty cycles as well as attempt a reset & relearn. This level of diagnosis and troubleshooting is beyond my skillset and budget. I think at the end of the day you're best off finding a competent/experienced mechanic to troubleshoot this. It might be costly, but has the potential to save you serious cash if parts keep getting thrown at it.
-Icer

 

I agree! I have spoken to my mechanic and he said try to run a good cleaner like seafoam in the oil or another and really romp on it. Let it work it's way in and do an oil change and see where I stand. Thanks for the help.

 

OK, so I tried the flush trick using Seafoam because they don't sell the bg products here. Idled it for 30 minutes and even revved it a couple of times in that time. Changed the oil and cleared all the codes. Did the timing relearn sequence and I still have this stupid *** code popping up. Could it actually be that the vvt solenoid from the intake side causing a loop and making the exhaust side compensate for it? I'm out of ideas and even the Stealership is stumped on this. Any new ideas would be great!

 

Hey Havoc,

Sorry to hear the flush didn't work. There could be something going on with the intake solenoid, but I would check with a competent tuner shop or mechanic before dropping any more cash on parts. I'm surprised the dealer is stumped. I see you're in Texas, there are a lot of good shops out there, but they might require you to do some traveling. Good Luck!
-Icer

 

I'm just going to call my tuner Kenny Tran at Jotech Motors ports and see what he says. Thanks.

 

OK! This car is driving me nuts. Went and changed out both the top cam sensor on exhaust side (bank 1) and the bank1 vvt solenoid. Both are brand new. Performed the timing relearn. Now getting a p0011 code. That code never popped up before. I guess I'm looking at changing those cam sensors also and the bank 1 vvt solenoid.