V36 Skyline - Strange misfires/bogging/reving issues

[VirtualWolf]

Hi folks,

I'm wondering if anyone can shed some light on the issues I'm currently experiencing, personally I believe its one of my throttle bodies gone but maybe someone else has experienced something similar.

Basically I just started my vehicle and drove home, noticed that at periodic moments it would rev up approximately 3,000rpm above what it was on even with foot off the accelerator pedal, braking stopped it revving.

I got home and sat it Idle, at the 3k or just above it mark it will rev to 6k without me touching the accelerator along with a peculiar noise.

For reference I've checked the MAF sensors/reset ECU/idle learning/etc/etc, the ECU is throwing absolutely zero codes at me although the light will come on occasionally when it happens.

Any ideas?  Thanks in advance for reading :)

[sonicii]

what are you using to read the codes?  if the CEL has come one, even for moment, it should have a code stored.

[VirtualWolf]

Thanks for responding Sonicii, I was only using the CEL flashing method.

Today I managed to get hands of a proper consult device and the following is returned along with videos of voltages/etc of when it occurs. Although I no longer have access to it I'm sure this should be enough info to figure it out.

Codes:
P0123 - TP SEN2/CIRC-B1
P0223 - TP SEN1/CIRC-B1
P0228 - TP SEN2/CIRC-B2
P2133 - TP SEN1/CIRC-B2

Videos of sensor data:
 

 

 

 

[sonicii]

same fault with both TPS at the same time seems unlikely.  I would be looking for something in common.  Grounding or power supply wiring?

[VirtualWolf]

There was an incident whet I may or may not have charged the battery using another and accidentally threw positive on negative terminal.  Sparked but nothing seemed damaged, in saying that I have grounding cables going to each throttle body. (removed them to see if this was the issue but to no avail)

[sonicii]

On 1/1/2022 at 3:42 PM, VirtualWolf said:

There was an incident whet I may or may not have charged the battery using another and accidentally threw positive on negative terminal.

Eeek,  that is often catastrophic, can't say for sure if this is the cause of the issue, but it is entirely possible.  You don't happen to have any friends with a V36/370Z you can swap the throttle bodies over and see how it goes?

[VirtualWolf]

Probably noteworthy to also mention it only touched it for a moment but that was quite a while ago.

 

I sourced some second hand throttle bodies and the issue continued.... I'm stumped at what it could be.  Maybe the car lost its uprev tune or the low exhaust caused a crack in one of the extractors (as it does make a weird sound through the exhaust towards the front).

[gillies2001]

Hi there 

I had a similar issue with my V36. The problem was worse in stop start traffic,  rough idle, revving up and them stalling. (But only sometimes) It seemed like the fuel mixture was way too rich. Did all resets, replaced most sensor's, and the throttle bodies. No change at all. No fault code's.   Someone mentioned fuel pressure regulator. (Did a pressure test, 52lb at idle) So I removed pump bucket from the tank, BINGO the FPR was badly corroded.                  The fix.....ordered the fuel line return kit from CJ Motor Sport, and fitted an under bonnet fuel regulator. Also a new fuel pump.  Problem solved.

Try YouTube  The Aussie Shed.   He shows the complete job in great detail.            Hope this helps

 

 

 

 

 

[VirtualWolf]

On 14/01/2022 at 5:02 PM, gillies2001 said:

Hi there 

I had a similar issue with my V36. The problem was worse in stop start traffic,  rough idle, revving up and them stalling. (But only sometimes) It seemed like the fuel mixture was way too rich. Did all resets, replaced most sensor's, and the throttle bodies. No change at all. No fault code's.   Someone mentioned fuel pressure regulator. (Did a pressure test, 52lb at idle) So I removed pump bucket from the tank, BINGO the FPR was badly corroded.                  The fix.....ordered the fuel line return kit from CJ Motor Sport, and fitted an under bonnet fuel regulator. Also a new fuel pump.  Problem solved.

Try YouTube  The Aussie Shed.   He shows the complete job in great detail.            Hope this helps

 

 

 

 

 

Thanks for the reply, took it to 2 shops today including na auto electrician... No real info aside from it possibly being the pedal itself and some more data.

 

Is this similar to what you had?

[gillies2001]

I did have 1 fault code, "which was missing on all cylinders", forgot the actual code.

Turns out that was telling me RICH MIXTURE  I didn't realise that at time.

[gillies2001]

This is how the fuel pressure regulator looked when it was removed from the pump bucket  UGLY 

[VirtualWolf]

Jeepers that looks a bit tedious, so it was removed and relocated to engine bay?  Where did you put it?

[VirtualWolf]

Just wanted to say this was all resolved by unplugging the battery for 24 hours then doing the relearn procedures.  Can't say whether the replacement accelerator pedal/throttle bodies even helped, would recommend for anyone in future struggling with this issue to do this first.