67 replies to this topic

[sponaugle]

Update:   I moved the relay such that it is in parallel to the factory SUB FUEL PUMP RELAY as shown in Nick's Diagram.  The relay is now activated by the same lines that activates the factory relay, and the out of said relay is connected to the fuel pump in parallel with the factory line.  

 

I did this thinking it might still allow the ECU to see some voltage drop when the pump first kicks on.  

 

It did not work.    It took a few more pulls to get the code to pop, but the ECU still threw the P0627.   I added a switch so I could eaisly disable the second relay, and as soon as it is disabled the code goes away.   It would appear the factory calibration is looking for that small voltage drop as a result of the limited wire size.

 

I disabled the code and all is well.

 

I am curious if others that do the direct wire have also disabled this code?  Is this unique to the 2014?

 

Jeff

[NickTO]

Jeff,  couldn't reply til today... spending some time in Germany and didn't have data on my phone

 

I installed the 2ndary relay in parallel because it was my observation that it would throw a DTC otherwise.

 

 

I have not triggered (nor disabled) any fuel pump DTC on my '09 and no trouble for the past 2 years with this... I don't think others with the same setup (not sure if same MY as yours) have encoutered this either...

[FreakofNature]

Jeff,  couldn't reply til today... spending some time in Germany and didn't have data on my phone

 

I installed the 2ndary relay in parallel because it was my observation that it would throw a DTC otherwise.

 

 

I have not triggered (nor disabled) any fuel pump DTC on my '09 and no trouble for the past 2 years with this... I don't think others with the same setup (not sure if same MY as yours) have encoutered this either...

Well, I'm glad I've been away for awhile and haven't had a chance to perform this on my 2013.  I guess my question to everyone would be, has anyone performed this mod on a 2012 or newer GTR and if so have they had any issues with fault codes popping up?  (Outside of  sponaugle (Jeff)) 

 

I know it would be easy to just disable the code but I like having the idiot lights working as much as possible in the event there is a true fault, not just a false positive.

 

Cheers,

 

Steven

[sponaugle]

Jeff,  couldn't reply til today... spending some time in Germany and didn't have data on my phone

 

I installed the 2ndary relay in parallel because it was my observation that it would throw a DTC otherwise.

 

 

I have not triggered (nor disabled) any fuel pump DTC on my '09 and no trouble for the past 2 years with this... I don't think others with the same setup (not sure if same MY as yours) have encoutered this either...

Hey Nick,

 

Yes, most people in the older cars have not seen this.  I did some more testing by adding a manual switch to allow me to activate or deactivate the second parallel relay.  Sure enough as soon as it is enabled and the pump kicks on, the ECU throws the code.   I assume they added some additional functionality to detect when a pump circuit is open.  If I keep my second relay disabled, no code.   I repeated the test a number of times, including having the actual pump itself disconnected.   With either the single relay or both relays the ECU had no problem detecting when the pump was disconnected.  

 

It is a actually a novel approach to make a safety system.   Without it you really have no way to know your second fuel pump has failed.

 

For now I have disabled that code.   Fortunately I am testing out the Cobb safety system modifications, which includes fuel pressure monitoring.  That can detect pump failures as well as electrical connections to the pump.

 

Jeff

[HiBoost]

Great additions to the topic!

[Arkmae]

after having issues with my 1050cc injectors and 265lph fuel pumps maxing out on just a stock turbo FBO setup it appears i may need to resort to this. gonna give it a crack this week. 

[FreakofNature]

after having issues with my 1050cc injectors and 265lph fuel pumps maxing out on just a stock turbo FBO setup it appears i may need to resort to this. gonna give it a crack this week. 

Yep, same setup here and was disappointed with the performance of the combo on E85 running 20psi FBO. On paper it should have been enough but "real world" dictated differently.

 

I did this hardwire over the weekend and I can report that my IDC% did go down about 9% but I noticed the check engine light flicker every once in awhile.  The light doesn't stay on and there is no additional info being displayed in the information center.  It happens very random so I'll pull the codes shortly to see what's up and report back.  If it's the same code as Jeff had, I'll just have Ben supress the code and as Jeff is doing, will add the fuel pressure monitor once Ecutek gets the programming done.

 

The wiring on the relay's to my astonishment were very small for the coil side, I'd say 16 AGW for the coil, and 14 AGW for the contact .  I'm wondering if the codes are because of a major drop in volage triggering two relays?

 

So yeah, MY2013 with this hardwire method will trigger a code.

 

Cheers,

 

Steven

[HiBoost]

Steven, are you on ecutek? I ask because a flashing check engine light could be the knock warning feature if your tuner has enabled that.

[Arkmae]

Guys,

 

will going to bigger pumps and injectors alleviate any issues and provide safe headroom?

 

thinking i should go to twin walbro 485s and ASNU 1600cc injectors instead.

 

Or will i still have fuel pump problems because of this issue?

 

Thanks

Edited by Arkmae, 21 October 2014 - 05:42 PM.

[FreakofNature]

Steven, are you on ecutek? I ask because a flashing check engine light could be the knock warning feature if your tuner has enabled that.

Yes, I'm on Ecutek and you may be right.

 

I wasn't really getting into it because it was down into the 30's that morning and I haven't swapped the R888's for my winter tires yet.  Who knows but your theory is plausible because Ben@GTC does have the knock warning enabled.

 

I did just pulled all the DTC's a moment ago:

 

Performing DTC Operations on Nissan GTR R35 Transmission ECU ->2013MY...
    Reading DTCs...
      0 DTCs Read
  End of DTC Operations on Nissan GTR R35 Transmission ECU ->2013MY...

Performing DTC Operations on Nissan Tyre Pressure Monitoring System...
    Reading DTCs...
      0 DTCs Read
  End of DTC Operations on Nissan Tyre Pressure Monitoring System...

Performing DTC Operations on Nissan Suspension ECU...
    Reading DTCs...
      0 DTCs Read
  End of DTC Operations on Nissan Suspension ECU...

Performing DTC Operations on Nissan Air Conditioning & ABS ECU...
    Reading DTCs...
      0 DTCs Read
  End of DTC Operations on Nissan Air Conditioning & ABS ECU...

Performing DTC Operations on Nissan Air Conditioning ECU #2...
    Reading DTCs...
      0 DTCs Read
  End of DTC Operations on Nissan Air Conditioning ECU #2...

Performing DTC Operations on Nissan Body Control Module...
    Reading DTCs...
      0 DTCs Read
  End of DTC Operations on Nissan Body Control Module...

Performing DTC Operations on Nissan All Wheel Drive ECU...
    Reading DTCs...
      0 DTCs Read
  End of DTC Operations on Nissan All Wheel Drive ECU...

Performing DTC Operations on Nissan IPDM ECU...
    Reading DTCs...
      0 DTCs Read
  End of DTC Operations on Nissan IPDM ECU...

Performing DTC Operations on Nissan Pop Up Hood...
  DTC Reading NOT Supported for this Module.
  End of DTC Operations on Nissan Pop Up Hood...

Performing DTC Operations on Nissan GTR R35 Engine ECU 2011->...
    Reading DTCs...
      0 DTCs Read
  End of DTC Operations on Nissan GTR R35 Engine ECU 2011->...

 

So, so far no code has been thrown for the secondary pump being wired up per NickTo's instructions, which is a good thing. 

 

Thanks Jeff, you motivated me to get off my ass and pull the codes to make sure.   If things change I'll give everyone an update.  It would be nice to make a list of MY's this mod will work for without throwing a code.

 

Cheers,

 

Steven

[FreakofNature]

Ok, pulled the code: P0175 System Too Rich (Bank 2).  I need to do some logging as it appears to be that Long Term Fuel Trim issue some people are having.  Not sure what the fix is but I'll keep people posted.  I've never had a problem with the car until this point, such is life.

 

Cheers,

 

Steven

 

Well, I spoke too soon.  I popped a check engine light this morning.  When I get home I will check which code and report back.

Edited by FreakofNature, 24 October 2014 - 03:34 PM.

[HiBoost]

Nick,

 

A couple questions to clarify your recommendations...

 

1)  In your PDF, it appears you are showing 2 alternative methods, not 2 steps of a single method, correct?  I.e. the first approach is just bolstering with additional power lines and no relays, the second approach involves power lines + relays.  If that's the case, and both will work, when are the additional relays recommended?

 

2)  In the case where the relays are used, couldn't the wire to pin 10 on the FPCM be left intact and simply bolstered like in your first picture?  The new relay could get its trigger as shown below

 

 

Any reason that wouldn't work?

[NickTO]

I am showing 2 steps, One for primary, one for secondary pump.

 

The first page shows the wiring overview

[HiBoost]

Ok, thanks for clarifying that.  Any thoughts on my alternative connection to avoid cutting any wires?

[NickTO]

Sorry, I was in the middle of three things when I posted earlier.  Yeah that should work ok.  I just don't generally like using the contact and the coil on the same hot wire, but don't see why it wouldn't work...

[Raceadolf]

This is a huge help. Any picture of the install? Where did you pick up your relays at? How close to the fuel pump do you have to connect the hardwire to?

[haul s]

 
2)  In the case where the relays are used, couldn't the wire to pin 10 on the FPCM be left intact and simply bolstered like in your first picture?  The new relay could get its trigger as shown below
 
fuel-wiring.png
 
Any reason that wouldn't work?

Once the relay gets closed, how would it ever open again? The direct +12V wire tapped at the battery would keep the coil (and the pump control module) energized through the closed relay, and keep the relay closed forever, no? I think you'd then need to tap it just past ignition relay at IPDM so that relay and pump controller shut off when you turn off the ignition.

[NickTO]

Good point.

[HiBoost]

Once the relay gets closed, how would it ever open again? The direct +12V wire tapped at the battery would keep the coil (and the pump control module) energized through the closed relay, and keep the relay closed forever, no? I think you'd then need to tap it just past ignition relay at IPDM so that relay and pump controller shut off when you turn off the ignition.

 

Yeah, good catch.  So instead of hooking the relay's 86 to the FPCM's pin 10 it seems like hooking it to pin 7 would be the best.  That would solve your and Nick's concerns and still avoid cutting any wires if I'm not mistaken.

[shawnhayes]

I think you'd then need to tap it just past ignition relay at IPDM so

 

I still want to kick the MF that designed THAT piece of shit in the nuts.

 

Shawn