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Variable Valve Timing Issue - in the Link or Mechanical?


BeallJK

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Hey guys - 

I had the car out today and I am noticing that Driver's Side (LH) VTC position is not changing while driving like the Passenger RH side is.  

I have a table setup in my main screen to monitor Variable Valve Timing.  To the extent that I have both LH and RH Duty Cycles, VTC Targets, and VTC Positions up for monitoring.

Both banks have duty cycle, both banks have targets that change like you'd expect - I'm more than happy to upload a log screen shot or a live log.  

but RH Passenger Side has moving/floating around VTC position while LH Driver's Side is pegged at 0 all the time. 

For what it's worth, I'm running a 10w-40 oil (due to larger clearances on my rods, OEM is 5w-30) and I have heard people having issues with thicker oils and VTC - all opinions welcome.  

 

Initial Trouble Shooting:

1. Checked both connectors and wires up to each connector - both plugs and wires look to be in functioning condition.

2. Disconnected both plugs (one at a time), put a volt meter on each and they were both were reading voltage - somewhere between 4volts and 8volts at/near idle.  Furthermore, verified (when unplugged) the Link showed 0 on the position for each connector.  

3. Found a donor VTC Solenoid, cleaned w/brake cleaner and put 12volts on it to ensure it's functioning.  I then replaced the Driver's Side VTC Solenoid and this did not cure the issue.  Additionally, when I applied 12volts to the original solenoid it clicked like it's replacement.     

4. Got into the Link's Trigger Scope Feature and assigned Trigger #2 as the LH VTC position sensor and started/ran the car.  Captured the positions and Trigger #2 is showing up.  

5. Jumped into the Link and reviewed my VTC Settings and Tables - nothing jumped out at me but I am not well-versed in these sections of the programming.  

 

My question:  

Before I go and rip apart my timing chain case to chase this non-function VTC position am I missing anything?  

Is it possible that the Link has a setting that is restricting VTC action on the LH side?  

Is there anything else related that could be causing this issue that I am not seeing?  

 

Thank you again for your help!

James  

 

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Update: 

For what it's worth there is an o-ring in the VTC gear valve cover plate and sure enough the oring was damaged.  I can only assume that I messed it up during install.  I installed a new flat rubber oring, fired the car up and VTC is functioning on both sides.  

Issue:

Fixed:

 

 

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Gents - 

Seems the issue is back - 

A few things: 

I stopped by nissan on Monday and bought two OEM seals for the VTC Plates/Covers, reinstalled, and re-RTV'd and gave the car a day to cure-up.

Got the car up and running tonight and the VTC tables were being rather strange. 

 

RH side was essentially dead and was not responding, duty cycle was at 5% and no value on target regardless of what I put in the table) and no position movement.

LH side was jumping around duty cycle was between 5% and 10% , no value on the target (unless I put a small target, ie 1, 2 or 3 degrees into the table as a test), and position would jump around (mostly around 9 degrees or 18degrees).  

Both solenoids measured about 9ohms of resistance and responded to 12volts of power 

RH Solenoid was getting .9volts

LH Solenoid was getting 2.4volts

I'm going to check voltage at the ECU next...

Is there a reason the two banks would have different targets?  Why isnt the Link recognizing when I change a minimal value in the target table on both banks' targets

These VTC sensors are about 1year old and are Hitachi brand.  I have additional sensors I will swap in and/or go buy new Hitachi sensors if needed.

Any suggestions are welcome.  Attached are my datalog and a video. As always thank you!  

 

2020-09-29 VTC Test Run.llg

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You have the cam angle test running in the video and log, the VVT will not work when running the test - all cams are sent to the home position.

From the look of all the errors you probably have to reset the VVT offsets.  Your video is too blury for me to see what is going on.

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Thank you Adam!  

Yes, I had the Cam Angle Test running.  I will ensure that is off and re-run the test.  I'll get a more formal screen shot / video recorder (rather than my phone).  

Forgive my ignorance - is there a resource / tutorial / instruction set to reset the VVT Offsets?  

Thank you again!

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Thank you Adam - I appreciate your insight and instruction - surprisingly reading your instructions were clearer than what Link has in the directions. 

My LH Intake side is back to zero but the issue with duty cycle still remains.  I can put a small duty cycle in the table but the RH Intake Target nor Duty Cycle are not changing like the LH Intake duty cycle and targets change.

If I go to my F12/Runtime Values, under the VVT Status 'Inlet/LH Signal' displays "Error: Extra Pulses" and Inlet/RH Signal displays "No Signal" (I can upload a screen-shot video tomorrow). 

Does this indicate that my RH Passenger side VVT Sensor is not reading and/or conveying a signal?   

I did swap out both driver & passenger side VVT sensors and the problem persisted.  

Thank you again!   

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More unexplained answers ... 

So I took a previously saved tune (roughly the same tune minus some minor fuel changes from maybe 2months ago) and all these VTC issues have gone away?  

I can't explain it and I'm not sure what to say??  I'm gonna reload PC Link and start from that older map.  

 

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  • 2 weeks later...

I performed the 'compare' feature and nothing really jumped out at me.  And the problem has come back.  

The car runs well / smooth while in 'cam angle test' and no significant duty cycle is being applied but as soon as you turn the 'cam angle test' off the engine runs choppy.  

Resetting the Cam Angle Offsets did not appear to help either.  

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