Nistune Forums

Matt, others, I have found that if you transfer the knock filter values of the RB25 over to the Z32 map, it becomes less sensitive to (false) knock detection.

the table for the RB is:


and the Z32:


lower values means less sensitivity

I think these values can be found within Nistune, under section "knock limit".


regarding the fueltemp problem, let me know what ECU/ROM partnumbers are giving trouble and I'll try to replicate the problem and find a solution.

EDIT: I have just checked the documentation and maybe the fueltemp resistor problem is related to the fact that (according to the pinout documentation) the resistor on pin 36 is not ground to a chassis ground (eg. pin 107/108/116), but to an internal ECU ground ?
I always use a chassis ground...as the original sensor is also using a chassis ground

Hi Eric,
Thanks for the input.

My ECU-Number is:
23710-41P03 REV: 14 U

As for the knock limits I had these transferred from the RB25 anyhow.
However in Nistune there seems to be a different representation of the values?

In addition there is just one table for the RB2 though it has 2 knock sensors.
What do these values exactly stand for?

Hi Torque,

I can tell that the ecu is on knock maps when the engine is at idle. The lambda sits around .83 and it idles bad, I haven't yet tuned fuel on the knock maps so its rich as hell.

Around 3500 under load the ignition retards to 0 degrees



I took some readings with my meter which I hope might help:

Sensor Ground--to--Fuel Temp Pin - 1444 ohm
Sensor Ground--to--Fuel Temp Pin with 2.2k resistor - 850 ohm
Sensor Ground--to--Fuel Temp Pin with 2.2k resistor between chassis and fuel temp - 1441 ohm
Chassis Ground--to--Fuel Temp Pin with 2.2k resistor between chassis and fuel temp - 2203 ohm

I tested 1.5k, 2.2k, 3.3k, 5.5k with no success.

I also checked voltages on the fuel temp pin between chassis ground and sensor ground, the only reading I could get was 0.17 volts? I even tried feeding the pin with 4v but it still threw the code.

Ecu number on the case is 23710-41P13, although I was told that it may not be the original cover.

I have taken the ecu out at least 20 times trying to fix this

Cheers for the help

This is a better example of the ignition retarding. Notice how it is almost the inverse of load.
What would make the timing do that?

>> What would make the timing do that?

can you post or send me a copy of the bin you are using ?
..so I can have a look at what may be causing that.

Hi!

I have attached my log snapshot which is under load on the road.
My timing with TP-Load=96 was 13. (I hope that is BTDC)

During this log session (40 minutes with various load conditions) the timing was between 45 and 5.

At least we agree on the FUEL TEMP


What setup has the RB25?
Is it spec2?

Hi Crans,

The value of Sensor Ground--to--Fuel Temp Pin with 2.2k resistor - 850 ohm is what I have measured as well.
Matt confirmed this value in an EMail to me.

How did you measure these:
Sensor Ground--to--Fuel Temp Pin with 2.2k resistor between chassis and fuel temp - 1441 ohm
Chassis Ground--to--Fuel Temp Pin with 2.2k resistor between chassis and fuel temp - 2203 ohm
??

Was the plug connected to the ECU when you measured the last 2 values?

Unplugging the ECU that many times must really be annoying!

I trust we'll find out what causes this.

Is your Skyline Spec2?

crans wrote:Hi Torque,

I took some readings with my meter which I hope might help:

Sensor Ground--to--Fuel Temp Pin - 1444 ohm
Sensor Ground--to--Fuel Temp Pin with 2.2k resistor - 850 ohm
Sensor Ground--to--Fuel Temp Pin with 2.2k resistor between chassis and fuel temp - 1441 ohm
Chassis Ground--to--Fuel Temp Pin with 2.2k resistor between chassis and fuel temp - 2203 ohm

I tested 1.5k, 2.2k, 3.3k, 5.5k with no success.

I also checked voltages on the fuel temp pin between chassis ground and sensor ground, the only reading I could get was 0.17 volts? I even tried feeding the pin with 4v but it still threw the code.

Ecu number on the case is 23710-41P13, although I was told that it may not be the original cover.

I have taken the ecu out at least 20 times trying to fix this

Cheers for the help

The ECU was out of the car when I took these ohm readings, voltage when it was installed and ignition on.

I used the map supplied with the nistune chip, which had the transferred RB25 maps.

I adjusted fuel and ignition maps a bit, and set up VCT to work with RB25, I think I left everything else as standard.

The car is a Series 2 GTST

Hi...

The issue (with the FUEL TEMP) is not inherent to the Z32 ECU but inherent to the difference between
R33 SPEC1 and R33 SPEC2.

The SPEC2 LOOM has a connection at PIN36 (FUEL TEMP ON Z32) which controls the FAST IDLE CIRCUIT on the SPEC2.

Since PIN36 (Z32ECU side) is still connected to the internal 2k resistor (the one you soldered in to simulate the fuel temp sensor)
the Z32ECU produces a false reading there.


In addition the SPEC2 has a closed throttle switch (PIN54) to indicated idle.
So it is not necessary to cut this connection when modifying the Z32 ECU.
(see point 4. in the Z32_ECU_Modifications_Direct_R33_Plugin V5.pdf document)

I hope this helps

This has to be incorporated into the Z32_ECU_Modifications_Direct_R33_Plugin V5.pdf document to save other folks the trouble
I went through.

(I don't think that this has a real impact on the operation of the Nistune ECU, but it prevents the Trouble code for the Fuel Temp Sensor.)

I've forwarded that onto PL to update in the next document

So S2 Skylines need ER34 AFM in the mapping also and I'll put together S1 and S2 merged maps with the knock sensor tables and other tables you've identified above

Matt I am using a S2 AFM in my S1.5 R33 So either the S1.5 uses it as well or there is no difference between them as i have had no issues and no tune tweeks to get it running smoothly.

I should note this is in my R33 running an RB20 ECU not my frieds S2 R33 running the Z32 ECU

Hi Matt,
I will rewire my S2 ECU to incorporate my findings.

I also want to reconnect the closed throttle switch.
(PIN54)

Would that have an impact on the Z32ECU's internal program?
I mean have you changed the firmware with regards to that there is (supposedly) no TPS-Switch?

Cheers,
Andrew

Matt wrote:I've forwarded that onto PL to update in the next document

So S2 Skylines need ER34 AFM in the mapping also and I'll put together S1 and S2 merged maps with the knock sensor tables and other tables you've identified above

The S2 VQ-Map is slightly different to the S1-Map.
In fact is is the same as the R34-GTT.

crans wrote:Matt I am using a S2 AFM in my S1.5 R33 So either the S1.5 uses it as well or there is no difference between them as i have had no issues and no tune tweeks to get it running smoothly.

I should note this is in my R33 running an RB20 ECU not my frieds S2 R33 running the Z32 ECU

Z32 image is just 41P04 with RB25 maps copied on there (no firmware changes)

Z32 detects if no TPS switch then it uses a limp value for idle. I've tried to modify it to hard code it to a specific value but my attempts seem to cause unwanted adverse affects which require more investigation. For now I just use the standard code. You can connect those tracks together no probs

S1.5 what is that? Oh no another variation

Good stuff Matt!

I read in the Z32 documentation that the idle switch is normally not used by the ECU anyhow.
I will rewire my ECU and let you know how it worked out.

Don't worry about S1.5 ... this was never official.

Matt wrote:Z32 image is just 41P04 with RB25 maps copied on there (no firmware changes)

Z32 detects if no TPS switch then it uses a limp value for idle. I've tried to modify it to hard code it to a specific value but my attempts seem to cause unwanted adverse affects which require more investigation. For now I just use the standard code. You can connect those tracks together no probs

S1.5 what is that? Oh no another variation