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Exhaust Valve Timing on HR


Zod

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Guys,

 

I've been having an issue with my HR since I got her back on the road. Car drives ok when cold. Then the Revs stumble while driving at 1100 RPM and again at 1850RPM once she is warmed up. Also once I get under 3000RPM while decelerating (no feet on brakes or throttle) the car starts dragging suddenly then about 2200RPM it decelerates normally again. This makes driving around town a total pain.

 

What I've done so far:

- All relearns for throttle position, pedal position, idle relearn and even EVT calibration.

- Checked O2 Sensors

- Cleaned both MAFs

- Cleaned both throttle bodies

- Examined fuel trim values for clues

- Changed oil and filter 5w-30 fully synth

- Read workshop manual extensively!

 

I'm currently concentrating on the ECM and EVT and found that if I disconnect the two connectors for the EVT control then the car runs absolutely perfect. So thinking now that it is an issue with either the EVT or ECM or a different issue exasperated by these. I can see other people with similar issues have cured this with an Uprev map so maybe the ECM needs a reflash/update?

 

Anyone experienced something similar or know what the cause is from my description? Is there a know TSB for this, cant seem to find one myself..

 

Thanks

Keith

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Went through this last year and had the uprev done at TDI North. Some improvement but problem persisted. Eventually changed the flywheel and clutch ( at 24 k miles ! ) problem cured. Expensive job.

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Sounds like the normal HR issue , we have found this issue and sorted the issue in the stock calibration. Cars drive perfectly after.

 

Thanks

 

Ok thanks, so what exactly is the issue? Does an uprev fix the issue or compensate for it? Was planning on an uprev in the future but only after an exhaust upgrade.

 

Went through this last year and had the uprev done at TDI North. Some improvement but problem persisted. Eventually changed the flywheel and clutch ( at 24 k miles ! ) problem cured. Expensive job.

 

I don't think that's my issue, I just installed an Xtreme clutch and fly along with a low mileage gearbox. When I run without the EVT control the car is fine. I'd imagine it was probably the DMF in your case.

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In short the issue is the closed loop cam control on the exhaust cams.

 

It seems the PID set up is to aggressive causing the cam angle to move too aggressively and cause the stumbling issues

 

Ah, thanks Mark. I'm guessing this problem surfaces due to tolerences/reference values changing as the engine ages?

I'll be saving up for an Uprev soo :thumbs:

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  • 1 year later...

Apologies for reviving an old thread but I sorted this issue out yesterday and felt I should update. I put the Z back on the road this month for the summer and it still had these issues. I decided to run the EVT Relearn procedure again yesterday evening and it has completely resolved my issues. I must have done it wrong the first time.

 

Hopefully it helps someone with similar issues!

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What is the EVT relearn procedure ?

 

My car is a HR so not sure if this applies to previous engines.

 

Exhaust Valve Timing Control Learning NBS00038

DESCRIPTION

Exhaust Valve Timing Control Learning is an operation to learn the characteristic of exhaust valve timing con-

trol magnet retarder by comparing the target angle of exhaust camshaft with the actual retarded angle of

exhaust camshaft. It must be performed each time exhaust valve timing control magnet retarder is discon-

nected or replaced, or ECM is replaced.

 

 

OPERATION PROCEDURE

With CONSULT-III

1. Start engine and warm it up to normal operation temperature.

2. Set shift lever in neutral position and confirm that following electrical or mechanical loads are not applied.

– Headlamp switch is OFF

– Air conditioner switch is OFF

– Rear defogger switch is OFF

– Steering wheel is in the straight-ahead position, etc

3. Keep the engine speed between 1,800 and 2,000 rpm.

4. Select “EXH V/T CONTROL LEARN†in “WORK SUPPORT†mode with CONSULT-III.

5. Touch “START†and wait 20 seconds.

6. Make sure that “CMPLT†is displayed on CONSULT-III screen.

 

Without CONSULT-III

1. Start engine and warm it up to normal operation temperature.

2. Set shift lever in neutral position and confirm that following electrical or mechanical loads are not applied.

– Headlamp switch is OFF

– Air conditioner switch is OFF

– Rear defogger switch is OFF

– Steering wheel is in the straight-ahead position, etc

3. Keep the engine speed between 1,800 and 2,000 rpm at 20 seconds.

Edited by Zod
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Done this last night, drove the car this morning and it has worked at treat, drives so smooth now ! Even if I have to do it once a month it's worth it. I never had the same symptoms as you, just an inherent jerky ride but that's now gone ðŸ‘

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  • 1 month later...
On 6/15/2017 at 03:55, Dave6188 said:

Done this last night, drove the car this morning and it has worked at treat, drives so smooth now ! Even if I have to do it once a month it's worth it. I never had the same symptoms as you, just an inherent jerky ride but that's now gone ðŸ‘

 

Are you guys doing this without consult3?

I have to replace my VTC covers as I'm throwing codes p0024 and p0014 and I will need to do this exhaust reset procedure afterwords.

 

Hopefully it works without consult lol.

 

Thanks

Edited by Grummi
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Wait a minute I'm confused lol... Or not taking this in correctly, is the above a way of getting rid of the jerkyness? Or temporarily? 

 

I've got an HR and it does the lunge jerky thing around 1K bang on if your in slow moving traffic and try to move off.  You need to be suuuuper slow moving forward to miss it, letting the revs very gently rise.

 

I don't get the consult thing? or if something else would need to be done or if it is gonna throw codes up etc. 

 

 

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On 30/7/2017 at 10:38, AMT said:

Wait a minute I'm confused lol... Or not taking this in correctly, is the above a way of getting rid of the jerkyness? Or temporarily? 

 

I've got an HR and it does the lunge jerky thing around 1K bang on if your in slow moving traffic and try to move off.  You need to be suuuuper slow moving forward to miss it, letting the revs very gently rise.

 

I don't get the consult thing? or if something else would need to be done or if it is gonna throw codes up etc. 

 

 

 

Do this:

 

1. Start engine and warm it up to normal operation temperature.

2. Set shift lever in neutral position and confirm that following electrical or mechanical loads are not applied.

– Headlamp switch is OFF

– Air conditioner switch is OFF

– Rear defogger switch is OFF

– Steering wheel is in the straight-ahead position, etc

3. Keep the engine speed between 1,800 and 2,000 rpm at 20 seconds.

(Took me a few tries as the revs went over 2000)

4. Go for a drive

 

Mine is still running smooth since I originally did it, just recalibrates the exhaust valve timing, no codes. May or may not be your issue but it's worth a try!

 

 

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  • 3 months later...
On 8/2/2017 at 21:59, Zod said:

 

Do this:

 

1. Start engine and warm it up to normal operation temperature.

2. Set shift lever in neutral position and confirm that following electrical or mechanical loads are not applied.

– Headlamp switch is OFF

– Air conditioner switch is OFF

– Rear defogger switch is OFF

– Steering wheel is in the straight-ahead position, etc

3. Keep the engine speed between 1,800 and 2,000 rpm at 20 seconds.

(Took me a few tries as the revs went over 2000)

4. Go for a drive

 

Mine is still running smooth since I originally did it, just recalibrates the exhaust valve timing, no codes. May or may not be your issue but it's worth a try!

 

 

Sorry to revive a relatively old thread but I was getting the same issues, thought I needed a new clutch, then spoke to Zmanalex who suggested an uprev remap, whilst doing research, I came across this little nugget of info. I done it figuring it was free and what harm could it bring and it worked! I would highly recommend anyone who is having the same issues to try this out first before buying anything you (may) not need. Thank you Zod!

 

On 8/3/2017 at 20:18, AMT said:

I'll give it a bash, holding low revs shouldn't do any harm for 20 seconds so why not lol 

Since I'm replying to an old thread, just wondering how you got on with it? Did it work for you?

 

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It didn't work! Or I couldn't get it. Surely, this little thing can't get rid of the HR jerk?? I've read its to do with ecu timing cams or some thing or other. Has it really eliminated it so it doesn't hop about at low revs?? Usually happens around 1K ish in any gear if your low enough. If it does I'll certainly give it another go lol

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12 hours ago, AMT said:

 

It didn't work! Or I couldn't get it. Surely, this little thing can't get rid of the HR jerk?? I've read its to do with ecu timing cams or some thing or other. Has it really eliminated it so it doesn't hop about at low revs?? Usually happens around 1K ish in any gear if your low enough. If it does I'll certainly give it another go lol

Shame to hear it didn't work for you man. I've heard it's the exhaust cam timing? I can't speak for everyone but it definitely worked for me, turned the car on, waited for it to warm up, lights off, A/C off, don't think radio matters but I had it off also, kept revs in between 1800 and 2K for 20 seconds, not expecting anything, pulled away, and voila, no jumping. I purposely made sure that it wasn't coincidence, so I put it in 3rd going about 20mph, mine used to get jumpy around 1500rpm, and there was a nice smooth rise in the revs, so as far as I know, it seems to have worked, done the same thing a few more times to make sure it wasn't a fluke and it was all smooth. Not bad for a bit of free advice. I'd definitely recommend trying it again, just unfortunate if it doesn't work for you, means you may need a remap and/or clutch.

 

Let me know how you get on :thumbs:

 

 

Edited by eroll_350z
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I'll def try it again! I would hope not the clutch cos' the things been like that pretty much all the years I've had it lol I'll let you know how I get on, thanks again for letting me know it went well. Just wasn't sure it was a permanent cure lol

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Tried a good few times (pain in the a** trying to hold it lol) but still didn't work. Grrr cheers for the help though. I noticed when you bring the revs up slowly theres a skip at 1500 revs.  May be needing some laptop tuning action to see if it can be sorted. Lol dont care about power sharp throttle ..I jist want the jerk gone lol maybe take it to a place near here called dynatune see what they think

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