Misfiring 3,000-3,200 RPM V36 VQ35HR

[VirtualWolf]

Hey Folks.

My apologies for a semi repeat post but I couldn't figure out how to edit the original, and I've had further clarity on what may be causing the issue.

My Relevant Car Info:
-06 V36 Skyline VQ35HR
-Test Pipes
-Stillen long pipe intake
-Tuned with UpRev

The Issue:

1. Always under low throttle at the 3,000 - 3,200RPM range the car will misfire and shudder
2. This occurs intermittently at medium to high throttle
3. Only at this rev range (3,000-3,200RPM)
4. Full throttle has no issues
5. Makes no difference the gear
6. Notable hum/bog sound from exhaust prior to this occuring between 2000-3000 depending on throttle/accelerator position.
7. The only thing that has happened since I've had it tuned is repainted the calipers and its been running fine...well semi-unhappy with tune but fine for the past few months.
8. Video of said issue

What I've tried:

• Checked Throttle Bodies and cleaned
• Checked sufficient voltage is at the throttle bodies
• Checked plugs and coils
• Checked for exhaust leaks
• Checked intake and cleaned MAF & Pod Filters
• Checked MAF Voltage
• Checked Accelerator pedal position
• Had ECU scanned which originally returned codes such as throttle position sensor/accelerator position sensor, now its returning U1000 CAN bus communication/steer-ing wheel lock control unit/Signal: vehicle speed/Supply voltage/Select lever position/clutch switch PN signal/Steering column lock relay/ignition circuit monitoring relay/steering-wheel lock control unit.  Most of these codes are irrelevant and most likely related to the aftermarket alarm/other electrical shit that's been done.

A fellow is going to go over a few other minor things tomorrow just to double check if he can find anything, the original tuners put it down to possibly being the transmission however this doesn't explain why it only happens at this rev range nor why there aren't other issues.  It's been said that its definitely a tune related issue although how can a tune pop out?

Any further ideas or things to check would be greatly appreciated.

 

[VirtualWolf]

Hey Folks,

Finally had this resolved..well partially.

I decided to do a grounding kit but firstly one to the main block and 1 to each throttle body.  I honestly can't even begin to explain what a difference this made, although in this case im unsure if it was just a bandage to the problem.

Pro's
-Smooth Shifts
-Appears to shift at more appropriate times
-Less accelerator delay


I'm going to make to additional grounds to the trans/alternator/ecu/etc to see what kind of chances happen.

[DashyyPC]

Hey Mate. Quick question

What numbers did you get with the uprev tune? (+mods)

@VirtualWolf
 

Edited October 25, 2018 by DashyyPC

[VirtualWolf]

I'll upload a picture of the sheet when I get home but I think it came out around 276hp at the wheels, given it's an auto/sedan and the extra loss I think it came out alright.  I probably could've changed the plugs and done a few other mods.

Note: this was done on a dynapack

Edited October 25, 2018 by VirtualWolf

[VirtualWolf]

3 hours ago, DashyyPC said:

Hey Mate. Quick question

What numbers did you get with the uprev tune? (+mods)

@VirtualWolf
 

 

[colin.ssc]

What’s mods do you have?

[VirtualWolf]

16 hours ago, colin.ssc said:

What’s mods do you have?

Hey man just the following:

1.  Stillen Gen 3 Long air intake
2.  Megan Racing test pipes with custom dual exhaust Blitz mufflers and resonators.
3.  Some 12v to 16v ignition coil thing that came with it from Japan

[colin.ssc]

22 hours ago, VirtualWolf said:

Hey man just the following:

1.  Stillen Gen 3 Long air intake
2.  Megan Racing test pipes with custom dual exhaust Blitz mufflers and resonators.
3.  Some 12v to 16v ignition coil thing that came with it from Japan

Ah okay, not too bad results. Do you have the AFR charts as well? And did your misfiring issues got fixed?

[VirtualWolf]

15 minutes ago, colin.ssc said:

Ah okay, not too bad results. Do you have the AFR charts as well? And did your misfiring issues got fixed?

Unfortunately no AFR charts, I'll be sure to ask for them next time.  To be honest I was expecting a bit more, but I failed to take into account the drive-train loss.  Its definitely faster than it was before, noticeable throughout the range   However she does use a bit more fuel in general cruising and I thought that since the cats were removed it wouldn't have to dump as much fuel to cool them down.

The misfiring disappeared after I did a DIY grounding kit to each of the throttle bodies so I'm thinking one of the grounding wires is out to a throttle body and it was going out of sync at a specific throttle position.

Edited October 30, 2018 by VirtualWolf

[colin.ssc]

Ah okay, cool. How much did it cost to tune? Licence too? Want to see what you guys over east pay comparing to here.

 

Grounding kit definitely cleans up some issues (lag etc), surprised how bad the factory grounding was on these cars. 

Edited October 31, 2018 by colin.ssc

[VirtualWolf]

$1280 NZD all up

$22.00 - O2 boss and bung for wideband
$500.00 - Factory ECU reprogram to my specifications?
$50.00 - fit o2 sensor boss/pre dyno checks
$25.00 - Flash the car with uprev to confirm that it is flashing correctly
$65.00 - Dyno Setup
$390.00 - Full re-flash using uprev to suit mods (run itself)
$65.00 - Dyno removal

Add on 15% to the above prices for gst lol, as far as im aware I own the license and the license is locked to the ecu.

Edited October 31, 2018 by VirtualWolf

[VirtualWolf]

11 minutes ago, colin.ssc said:

Ah okay, cool. How much did it cost to tune? Licence too? Want to see what you guys over east pay comparing to here.

 

Grounding kit definitely cleans up some issues (lag etc), surprised how bad the factory grounding was on these cars. 

See above

[Jinfinity]

Sorry for being that guy and digging up an old thread but I am at a loss.

I am over in South Aus and I'm wantimg to get the uprev tune.

No one here can do it so I would have to do the Mail in Ecu Uprev through Z1Concepts over in the U.S.

I'm worried that it wont be as "Plug and play" as they say.

 

Also could you please post pics of how you did the Earthing kit. 

My car is having all sorts of rough running issues and everything has been checked or replaced with new parts.

Cheers mate.

[V35_Paul]

Do you think the uprev will fix your "rough running" ?

[Jinfinity]

Well I have taken the car to 6 mechanics 2 of which are specialized in vq motors.

Both of the mechanics have said that the ecu needs reflashing, now Not 1 nissan or infinity dealer in Aus is able to do it as all there diagnostic tools have been updated and has wiped the earlier infor or some rubbish. 

It has the High Rev out of sync with the shift points and just will not relearn the throttle bodies.  So I have done alot or research and that is my only option at the moment.

[VirtualWolf]

5 minutes ago, Jinfinity said:

Well I have taken the car to 6 mechanics 2 of which are specialized in vq motors.

Both of the mechanics have said that the ecu needs reflashing, now Not 1 nissan or infinity dealer in Aus is able to do it as all there diagnostic tools have been updated and has wiped the earlier infor or some rubbish. 

It has the High Rev out of sync with the shift points and just will not relearn the throttle bodies.  So I have done alot or research and that is my only option at the moment.

Hey dude, sorry to hear of your issues.  Have you installed test pipes?

Mine was actually a failing throttle body from which I was able to install one from a 350z and do the relearn sequence.

If you have the auto trans then uprev cant adjust the shift points or idle.  They really should've only suggested uprev if you're running test pipes or some other mods.

[DashyyPC]

14 hours ago, Jinfinity said:

No one here can do it so I would have to do the Mail in Ecu Uprev through Z1Concepts over in the U.S.

 

Nahhhhhhhhhhhhhhhhh.
Try Sinergy Motorsports in SA first. they installed and tuned their 300rwkw + SC 370gt sedan.

Call East coast customs here in brisbane (they used to do it that way you were suggesting) << Also im admin if VQ australia on FB so if you mention VQ aus to them, you will get a discount, Only speak to Rob.

 

Try Admin tuning If you want an E-tune. He sells the complete pack including cable, licensing etc.  

Best off doing those options rather then send your JPN ECU to USA.
 

[Jinfinity]

4 hours ago, DashyyPC said:

Nahhhhhhhhhhhhhhhhh.
Try Sinergy Motorsports in SA first. they installed and tuned their 300rwkw + SC 370gt sedan.

Call East coast customs here in brisbane (they used to do it that way you were suggesting) << Also im admin if VQ australia on FB so if you mention VQ aus to them, you will get a discount, Only speak to Rob.

 

Try Admin tuning If you want an E-tune. He sells the complete pack including cable, licensing etc.  

Best off doing those options rather then send your JPN ECU to USA.
 

Hey mate, cheers for the advice, Unfortunately It has already spent a whole week at Sinergy Motorsports and they said that the ECU need Reloading/flashing. They used to be able to do it by sending it to Main North Nissan and they could link up to Japan or something and do it. Apparently now they cannot do it as the consults have all been updated and either they cbf trying or they are just not knowledgeable at the dealership so they just refuse.

 

I'LL give you the Run down.

At cold start it revs upto 1900rpm then after 1 - 3 mins goes to 1500 then after 5 minutes it will eventually go down to 650-700.

The car seems to Vibrate or shudder when this happens until it is settled.

It feels sluggish and doesnt shift correctly and if you floor it will seem like its being held back. Also at coasting with light throttle it bunny hops and bounces up n down on the rpm.

After a while of driving and if i pull over and turn the car off then on again it start driving better. And will shift properly sound different in the exaust and drive alot smoother.

I have even tried reading the system with the BAFX obd2 scanner and torque pro and NDS3 and it wont connect.

I have changed the following.

Mafs

Spark plugs Ngk

All coils Hitachi

Coolant temp sensor

Both Vtc solenoids

All 4 cams shaft sensors

Pcv valve delete

Disconnected the Throttle bodies and cleaned them.

I am going to install a New battery tonight as the one it has keeps dying.

Also will be doing the Grounding kit.

Its really driving me crazy. 

[DashyyPC]

3 hours ago, Jinfinity said:

Hey mate, cheers for the advice, Unfortunately It has already spent a whole week at Sinergy Motorsports and they said that the ECU need Reloading/flashing. They used to be able to do it by sending it to Main North Nissan and they could link up to Japan or something and do it. Apparently now they cannot do it as the consults have all been updated and either they cbf trying or they are just not knowledgeable at the dealership so they just refuse.

 

I'LL give you the Run down.

At cold start it revs upto 1900rpm then after 1 - 3 mins goes to 1500 then after 5 minutes it will eventually go down to 650-700.

The car seems to Vibrate or shudder when this happens until it is settled.

It feels sluggish and doesnt shift correctly and if you floor it will seem like its being held back. Also at coasting with light throttle it bunny hops and bounces up n down on the rpm.

After a while of driving and if i pull over and turn the car off then on again it start driving better. And will shift properly sound different in the exaust and drive alot smoother.

I have even tried reading the system with the BAFX obd2 scanner and torque pro and NDS3 and it wont connect.

I have changed the following.

Mafs

Spark plugs Ngk

All coils Hitachi

Coolant temp sensor

Both Vtc solenoids

All 4 cams shaft sensors

Pcv valve delete

Disconnected the Throttle bodies and cleaned them.

I am going to install a New battery tonight as the one it has keeps dying.

Also will be doing the Grounding kit.

Its really driving me crazy. 

Hey man.

Sounds awful. If you could id move onto checking the following 

Fuel injectors 

Fuel pump

Clogged catalytic converter (if stock these are known to fail on early model v36 sedan/coupe) 

Possible the ecm is bad. 

I had a similar issue with my mps. Turns out I had a bolt going through some wires into the loom. Kept shorting out. I highly doubt its your issue but it's a possibility. 

 

P. S I've had the clogged catalytic converter issue and it ruined my drivability.

[Jinfinity]

So my cats have been hollowed out and I was going to get some stainless high flows welded in. 

Oh also replaced the rear post O2 sensors and when I took the old ones out they stunk of raw fuel on the passenger side.

I haven't checked the Injectors and I havent checked the fuel pump whats the best way to do this (Pressure tester or?)

Where is the ECM And Mps located. 

Can these buts just be replaced by second hand units withought some sort of reprogramming?

 

 Thanks for the help much appreciated.