Fuel Pump / Injector / Coil Pack Issues

[colin.ssc]

Shrugs......maybe 0w40 haha, I'll double check. I have not paid the bills as car is going back in for fuel pump change.

[Rufus007]

Just checking in for an update on how she's running now? Ie with new fuel pump etc if you have that installed now.

Shrugs......maybe 0w40 haha, I'll double check. I have not paid the bills as car is going back in for fuel pump change.

[colin.ssc]

Just had the pump installed a few days ago. So far starting the car has been without blip or any other issues. The old pump looks fine though.

The stutter is still there when I drive out, no luck with that one still. Reluctant to try the replacing VTC cover and solenoid cleaning since it's a big job. Any other ideas?

[Rufus007]

Is the stuttering still reduced running edge 0w40? Also does it still only happen in the first couple minutes of warm up? If so just keep using the castrol oil I guess. It used to happen to mine only below 2k rpm, so maybe try to drive just a little over 2k until the engine warms up?

You can force the exhaust valve timing to relearn with Nissan consult III software apparently, and there is also an android app called NDSIII that can do this:

https://play.google.com/store/apps/details?id=com.nissandatascan.ndatascaniii&hl=en

I found the ebay bluetooth OBDII adapters do not work with NDSIII, but I found one OBDII adapter from jaycar works well with NDSIII:

http://www.jaycar.com.au/Automotive-%26-Mobile-Security/Car-Alarms,-Protection-%26-Accessories/Tracking-Fleet-Monitoring/READER-OBD2-BLUETOOTH-4-0-ENGINE-CODE/p/PP2145

Final option before replacing VCT covers could be to get a tune to delay the time/temp until the VCT starts operating

hope that helps

[colin.ssc]

I've done the exhaust valve timing relearn.

The 0w40 delays the stutter timing - I am guessing that the stutter is happening at a certain temp that the VCT is trying to operate but is not hot enough to. Since the oil takes a bit longer to heat up and by the usual time I am already on the road I don't see it as much. What I did try was instead of warming up for the usual 2-3mins in summer, I did a 4-5mins warm up and the stutter came right away. I could be wrong, but this is just my observation. Scotty is scratching his head wondering why would the oil make a difference to the VCT hahaha.....

I guess the tune option might be the last thing to do now. I'll see. The shop that did my UpRev tune is not being too helpful at the moment. I've asked for the ROM multiple times and I am either ignored or getting a reply with we will send it shortly.

[Rufus007]

In a forum I read somewhere, there is an oem ECU update that fixes the problem... So it's possible software wise...

Edited March 21, 2016 by Rufus007

[scotty nm35]

Even if it is the VCT kicking in, why would that cause a stutter? Stuttering is likely running lean, it might be worth getting a wideband on it during this warm up period to see what is happening.

If that's the case a simple tune would fix it.

[colin.ssc]

Would the OEM wideband reading be ok to use?

[colin.ssc]

Don't know if you guys can make sense of this but

http://www.oppama-garage.jp/maintenance_report_6goki_20070408.html

[Rufus007]

I can only recite what I've read elsewhere regarding what people think is this issue. But the community agreed cause is that the VCT sensor isn't overly accurate. At low temperatures especially, the sensor is then setting the cams in the wrong place causing to much overlap at low rpm where overlap is not wanted/needed. And that is where the stutter comes from - low compression due to overlap, not fuel or spark issues.

So the overall solution here *might* be to delay the time the VCT's kick in at (giving the engine a chance to warm up a bit more first) - and I think this is what the oem software update does also.

Even if it is the VCT kicking in, why would that cause a stutter? Stuttering is likely running lean, it might be worth getting a wideband on it during this warm up period to see what is happening.

If that's the case a simple tune would fix it.

Edited March 23, 2016 by Rufus007

[Rufus007]

I would think so, have seen several people using NDSIII to monitor the widebands...

Would the OEM wideband reading be ok to use?

[scotty nm35]

I can only recite what I've read elsewhere regarding what people think is this issue. But the community agreed cause is that the VCT sensor isn't overly accurate. At low temperatures especially, the sensor is then setting the cams in the wrong place causing to much overlap at low rpm where overlap is not wanted/needed. And that is where the stutter comes from - low compression due to overlap, not fuel or spark issues.

So the overall solution here *might* be to delay the time the VCT's kick in at (giving the engine a chance to warm up a bit more first) - and I think this is what the oem software update does also.

The cam sensor is extremely accurate, but the cams have a self learn function which may need to be re-learnt for local conditions. Unfortunately they change their required PWM depending on oil viscosity/temp.

The delay for cam actuation is only to get the oil to operating temp, but it runs off the water temp, and there is a delay before the oil reaches the same temp as the water. I suspect this is where there might be an issue.

[Rufus007]

I always thought this issue was quite obviously VCT related though, like I initially posted. I also agree about the water temp vs oil temp disparity. I have previously bookmarked something along these lines also: (look at 13th post)

http://www.350z-uk.com/topic/64601-my-350z-hates-being-serviced-help/

If not inaccurate VCT control and setting, what do you think is causing the stutter then?

The cam sensor is extremely accurate, but the cams have a self learn function which may need to be re-learnt for local conditions. Unfortunately they change their required PWM depending on oil viscosity/temp.

The delay for cam actuation is only to get the oil to operating temp, but it runs off the water temp, and there is a delay before the oil reaches the same temp as the water. I suspect this is where there might be an issue.

Edited March 26, 2016 by Rufus007

[scotty nm35]

The VCT won't be making the stutter, it will likely be mixture related, possibly caused by the VCT positioning.

How many of you have checked or changed your fuel filter? or changed the filter baskets in the tops of the injectors? Just remember the wideband isn't accurate until the engine is up to operating temp either, so the engine is running off a base tune from when it was new.

I can only assume this stuttering is on a few cars? If it was VCT angles it would likely be on all of this model, not a couple. I would need to see one to diagnose further, but perhaps running it up on cold start on a Dyno might give you some more information, while logging the factory ecu signal outputs and o2 from the tailpipe with a hot Wo2 sensor.

[colin.ssc]

The VCT won't be making the stutter, it will likely be mixture related, possibly caused by the VCT positioning.

How many of you have checked or changed your fuel filter? or changed the filter baskets in the tops of the injectors? Just remember the wideband isn't accurate until the engine is up to operating temp either, so the engine is running off a base tune from when it was new.

I can only assume this stuttering is on a few cars? If it was VCT angles it would likely be on all of this model, not a couple. I would need to see one to diagnose further, but perhaps running it up on cold start on a Dyno might give you some more information, while logging the factory ecu signal outputs and o2 from the tailpipe with a hot Wo2 sensor.

So when are you visiting WA? =D you'll have access to accommodation and prob a workshop =P

[Rufus007]

So if the VCT angle sensor is accurate, do you then think the wrong VCT timing is being caused by the VCT actuators? If so maybe that's what the revised VCT actuator covers might address?

Judging by the lack of response so far this doesn't seem to be a large issue, and as I mentioned mine was sorted just by changing the engine oil to castrol edge.

The VCT won't be making the stutter, it will likely be mixture related, possibly caused by the VCT positioning.

How many of you have checked or changed your fuel filter? or changed the filter baskets in the tops of the injectors? Just remember the wideband isn't accurate until the engine is up to operating temp either, so the engine is running off a base tune from when it was new.

I can only assume this stuttering is on a few cars? If it was VCT angles it would likely be on all of this model, not a couple. I would need to see one to diagnose further, but perhaps running it up on cold start on a Dyno might give you some more information, while logging the factory ecu signal outputs and o2 from the tailpipe with a hot Wo2 sensor.

[colin.ssc]

I have seen a few people with 350z series ii having this issue as they have the HR engine as well. I don't know many of them but the few I know of have mentioned it. Specific to just the 35HR engine.

Edited March 30, 2016 by colin.ssc

[Rufus007]

I think there was some early vq37vhr affected also

I have seen a few people with 350z series ii having this issue as they have the HR engine as well. I don't know many of them but the few I know of have mentioned it. Specific to just the 35HR engine.

[scotty nm35]

How many of you have had the cam re-learn done on Consult3?

[colin.ssc]

No Consult3 still looking for one to use