Can You Diagnose This Problem?

[=premo=]

Specs:

-RB26/30 engine

-Power FC d-jetro

-RB26 engine wiring loom

-Car R32 gts-t (stock car wiring loom's)

Problem:

Car went in for a tune during week but it couldn't be finished because everything shuts down around 7psi boost or equal rev's. Power supply is fine and holds a constant 14v to 13.8v at power FC, coils and battery. Car drives fine before 7psi and never completely turns off but it does die very hard.

It seems like something is turning on and shorting out or interrupting the power FC causing it to crash or maybe something is meant to be turning on but its not connected so the power FC is turning off instead, the hand controller light dims when this happens and then everything goes back to normal straight away.

Have also noticed touching brakes or turning on lights causes electric gauge's to read low, sometimes at idle there warning lights come on, (they have good earth and power supply is on a relay with ignition switch trigger). Might be unrelated to main problem but would also like this fixed.

Its possible that the GTR's engine loom plugs that connect fine with the Gts-t's car loom plugs may have wires that aren't going where they are meant to but as said above car is fine at low RPM/boost.

If key is turned to acc and the ignition fuse is removed the AVC-R boost controller and Power FC turn on (power FC hand controller starts making a clicking noise) and everything else turns off. (This could be a result of car alarm although it does seem strange).

Does anyone know what could be turning on or causing the problem?

Has anyone had this problem before?

Does anybody have a clue about this because I'm about to slam it into the side of the bank that gave me the loan to do it, its really fkn with my head (spent 50+ hours on it over my week off to get it ready in time for the tune and now I wish I had of slept in and relaxed instead).

Thank you very much to anyone that can give any advice or help.

Edited August 8, 2008 by =premo=

[=premo=]

Even just a stab in the dark could help me with this. Any suggestion is worth trying.

[YLD-CHLD]

Even just a stab in the dark could help me with this. Any suggestion is worth trying.

wat sort of boost controller u running?might be shorting out when it trys to cycle.

Is it a standard fuel pump?Have heard of aftermarket pumps causing trouble if not installed correctly.

[Sydneykid]

Its possible that the GTR's engine loom plugs that connect fine with the Gts-t's car loom plugs may have wires that aren't going where they are meant to but as said above car is fine at low RPM/boost.

Bingo.

There are lots of differences between an R32GTST and an R32GTR. Some from memory

1 afm instead of 2

no air temp sensor

different water temp sensors

ATTESA ouput

knock sensors

1 lambda sensor instead of 2

TPS

provision for auto

injector impedance

What DJetro model do you have? I assume R32GTR?

You realy need to sit down with the two pin out diagrams and compare them pin by pin. The answer is most likely there in different usages for the same pin.

The hand controller is also useful, stick it on the sensor diagnostics screen and look for unusual readings.

Cheers

Gary

[=premo=]

wat sort of boost controller u running?might be shorting out when it trys to cycle.

Is it a standard fuel pump?Have heard of aftermarket pumps causing trouble if not installed correctly.

As said above, Apexi AVC-R boost controller but even with it turned off I still have the problem and its a nippen denso in tank fuel pump.

Bingo.

There are lots of differences between an R32GTST and an R32GTR. Some from memory

1 afm instead of 2

no air temp sensor

different water temp sensors

ATTESA ouput

knock sensors

1 lambda sensor instead of 2

TPS

provision for auto

injector impedance

What DJetro model do you have? I assume R32GTR?

You realy need to sit down with the two pin out diagrams and compare them pin by pin. The answer is most likely there in different usages for the same pin.

The hand controller is also useful, stick it on the sensor diagnostics screen and look for unusual readings.

Cheers

Gary

Yes I agree there are a lot of differences between the GTR engine loom and Gts-t engine loom but Im using a GTR engine loom and all of the engine running gear is from a GTR including the head, all sensors are for the GTR engine loom. So everything including the Power FC to the engine is from a GTR. The AFM's have been taken out of the wiring loom and replaced with the D-Jetro map sensors as instructed to do by the Power FC installation manual. GTR Air temp sensor, water temp sensor, knock sensor's and TPS are all connected to the ecu exactly the same way a GTR would be connected. The injector power supply has been re wired to the ballaster resistor pack (which is normaly wired to the car's loom on a GTR).

Im not sure what a lambda sensor or a ATTESA output is?

The differences that could be possible are the three plugs near the ECU plug that join the engine loom with the car loom. They are the same size plugs and seem to have the same amount of wires but its possible that the wires are connected to different pins in the plugs on a GTR compared to a Gts-t, I cant find any wiring diagrams of these plugs for either car so the only way to work it out would be stripping down the entire car and testing one pin at a time to every point on the car to see what it does then doing the same again on the engine loom... this could take many weeks and given that all head lights, dash instruments and wipers are working I would assume that these plugs are connecting correctly unless someone knows of a sensor or part that would cause this type of interference that I could look for in one of the three plugs???

I also have some spare plugs near the O2 sensors and wiper motor, I believe they are for ABS braking system but I could be wrong??

Thanks, any help is appreciated.

Edited August 9, 2008 by =premo=

[femno]

Dont forget about the connectors at the front of the P/S strut tower, i think they power up the ECU loom? (Thick wires = supply)?

You should be able to find wiring diagrams on the net? I know the GTR Service Manual has everything.

[=premo=]

Dont forget about the connectors at the front of the P/S strut tower, i think they power up the ECU loom? (Thick wires = supply)?

You should be able to find wiring diagrams on the net? I know the GTR Service Manual has everything.

There is a two pin plug (labeled 5 in pic) with thicker wires, could this have something to do with the power supply to the ecu?

Does anyone know what plugs into these plugs?

Thanks,

Daniel

[Cubes]

As you have mixed and matched a little its hard to say. The Rb26 pfc simply bolts in with very minimal changes to the GTST loom (primarily issues with multiple o2 sensor, multiple afm and airtemp)

If you are running with a single afm set the airflow correction to 50% across the board and then tune the airflow curve if you are running a q45 or if your running a z32 simply select z32.

You can then literally drive it to be tuned providing you set up inj. correction if need be.

I really believe looking down the path of ATTESA is barking up the wrong tree.

[=premo=]

As you have mixed and matched a little its hard to say. The Rb26 pfc simply bolts in with very minimal changes to the GTST loom (primarily issues with multiple o2 sensor, multiple afm and airtemp)

If you are running with a single afm set the airflow correction to 50% across the board and then tune the airflow curve if you are running a q45 or if your running a z32 simply select z32.

You can then literally drive it to be tuned providing you set up inj. correction if need be.

I really believe looking down the path of ATTESA is barking up the wrong tree.

Sorry, I don't understand what your saying. I dont have a Gts-t engine loom, I have a GTR engine loom and map sensor's not AFM's.

thanks,

Daniel

[Cubes]

Sorry bud what I was getting at is typically it just works. As you have mix'd and matched a little (gtst loom + gtr loom you did say your plugging sections of the gtr loom in to the gtst loom yeah?) it will be difficult to narrow down.

I am presuming the tuner has worked with djetro's before?

[=premo=]

Yeah tuner has done a few.

I haven't mixed the looms together, everything to do with the engine is from a GTR and everything for the car is stock (same thing you would do if you upgraded to an RB26dett). If you look behind your passenger kick panel you will see just up from the ecu plug there are three or more plugs that join the engine loom to the cars loom, its the same on a GTR. So all I have done is plugged it in the same way it used to be. Nothing apart from the power to injectors has been changed on either the Gts-t car loom or the GTR engine loom.

What I need to know at the moment is:

- What do the 5 plugs in the pic above do?

- Is there anything that could be turning on or interfering with the engine or ECU around this RPM or Boost?

- Is there anything that could be different in the plugs that join the engine loom to the car loom on a Gts-t vs GTR

And please keep the suggestions coming, Thanks people.

[acsplit]

Check your ballast resistor is wired correctly had similar issues when one was wired up incorrectly.

Those plugs above do not need to be connected.

[=premo=]

Check your ballast resistor is wired correctly had similar issues when one was wired up incorrectly.

Those plugs above do not need to be connected.

I currently have the power supply to the ballast resistor coming from ecu pin 109, could it be the power supply to the ballast resistor thats the problem or are you sugesting that the 6 wires to the injectors could be somehow wrong?

Should I setup a relay so that 109 is the switch and the ballast resistor power comes straight from the battery?

Thanks mate,

Daniel

Edited August 10, 2008 by =premo=

[BH_SLO32]

I think I may know what is going on. The turbo R32's have a fuel pump resistor (silver rectangular item) mounted on the passenger strut tower. Plug 5 in your photo is the connecting plug. If you haven't directly ground the fuel pump (ie the fuel pump wiring is standard), with the fuel pump resistor disconnected the fuel pump will run off a parallel circuit through the FPCM until the engine is warm and then it will switch off (pin 104 from ECU controls the FPCM operation) shutting down the engine. The fuel pump runs through the resistor circuit to earth most of the time but also through the FPCM circuit for a short period when started. So if the resistor is not connected the motor will run for a period and then just shut down. From my own testing it appears the FPCM switches off when the engine gets warm. This is the case for the RB20 ECU. The RB26 ECU control of the FPCM is similar.

Plug 3 and 4 are the O2 sensor (2 off) plugs, plug 1 is what I believe to be a diagnostic connector for the ECU tacho output (from memory). Plug 2 I think is the boost solenoid.

I have found some wiring differences with the R33 RB25DET and R33 RB26 white in-cabin plug (the plug near the ECU in the passenger footwell). I recall one of the differences was the switching wire for the FPCM. I would not be surprised if it is different with the R32 Rb26 either.

First thing I would do is connect the fuel pump resistor.

Cheers,

Ben

There is a two pin plug (labeled 5 in pic) with thicker wires, could this have something to do with the power supply to the ecu?

Does anyone know what plugs into these plugs?

Thanks,

Daniel

Edited August 12, 2008 by BH_SLO32

[=premo=]

I think I may know what is going on. The turbo R32's have a fuel pump resistor (silver rectangular item) mounted on the passenger strut tower. Plug 5 in your photo is the connecting plug. If you haven't directly ground the fuel pump (ie the fuel pump wiring is standard), with the fuel pump resistor disconnected the fuel pump will run off a parallel circuit through the FPCM until the engine is warm and then it will switch off (pin 104 from ECU controls the FPCM operation) shutting down the engine. The fuel pump runs through the resistor circuit to earth most of the time but also through the FPCM circuit for a short period when started. So if the resistor is not connected the motor will run for a period and then just shut down. From my own testing it appears the FPCM switches off when the engine gets warm. This is the case for the RB20 ECU. The RB26 ECU control of the FPCM is similar.

Plug 3 and 4 are the O2 sensor (2 off) plugs, plug 1 is what I believe to be a diagnostic connector for the ECU tacho output (from memory). Plug 2 I think is the boost solenoid.

I have found some wiring differences with the R33 RB25DET and R33 RB26 white in-cabin plug (the plug near the ECU in the passenger footwell). I recall one of the differences was the switching wire for the FPCM. I would not be surprised if it is different with the R32 Rb26 either.

First thing I would do is connect the fuel pump resistor.

Cheers,

Ben

I'll give the fuel pump resistor pack connection a go but the O2 sensors are already connected using the correct plugs. 3 and 4 in the pic are for something else.

The car can be driven fine at low boost and I've only been driving it once its warm so the problem isnt triggered by heat but it still might be worth a try.

Thanks

[femno]

4,5 and 3 are for the ABS unit.

I think 2 is for the wheel sensor.

1 doesnt usually have anything plugged into it.

[=premo=]

4,5 and 3 are for the ABS unit.

I think 2 is for the wheel sensor.

1 doesnt usually have anything plugged into it.

Thanks mate, but whats a wheel sensor?

[GTR-Ben]

Wheel sensor plug will be on the other side. That small one is for the Air con if that loom wraps around to the front.

I would be looking at the fuel pump control circuit first, something maybe earthing there when it tries to turn on.

Edited August 12, 2008 by GTR-Ben

[=premo=]

Wheel sensor plug will be on the other side. That small one is for the Air con if that loom wraps around to the front.

I would be looking at the fuel pump control circuit first, something maybe earthing there when it tries to turn on.

Nah all air con stuff is plugged in and the wires for these plugs are way to short to reach that far, they don't extend much past the windscreen wiper motor.

How do I diagnose if the fuel pump control circuit is shorting out?

The fuel pump is working fine but the Power FC could be trying to turn up the fuel pump so that it compensates for boost pressure on the other side of the injectors which would make sense why everything fails when it starts making boost. As said in BH_SLO32's post, could it be that I'm missing a fuel pump resistor or would it be that a signal from a pin on the power FC isnt getting to the right wire on the car?

Anyone know all the pins on the power FC or GTR ecu plug that goto the fuel pump control circuit so I can trace the wires back to try and find any shorts?

Is it just pin 104 and 18? (I cant find any software to open my pinout diagrams on this comuter so I might be wrong).

Cheers,

Daniel

[=premo=]

Thanks to Grigor and YLD-CHLD for helping me find the ecu pins, will have a look at them and other suggestions this weekend, if I can get it sorted then it will be in for another tune on Wednesday.

Pin 104 is FPCM output 1.

Pin 106 is FPCM output 2.

Pin 18 is fuel pump relay.

Does anyone know where the FPCM is on a Gts-t or know where the wiring for it runs?

Edited August 13, 2008 by =premo=