Nistune Forums

Hello Nistune community,

I recently installed a Nistune Type 1 board into my S13.

The specs of my car is as follows :

1991 European 200sx with abs, and o2 sensor.
Freshly rebuilt Ca18det with 9cr pistons
Stock maf and injectors (for now)
T28 turbo
AEM UEGO Wideband

1 : Board confusion :

The code on my ecu was 23710 - 39f00 so I ordered a Type 1 board with 39f00 ent on it. While trying to diagnose some problems, I saw that the eprom that I took out was labeled as MEC-D009D instead of MECD007D. My little research shows that MEC-D009D corresponds to the 44F07 ecu, which has no 02 sensor. My car has abs and an o2 sensor. The ecu had stripped screws, so it was sure opened before. The eprom chips soldering was not shiny like the rest, and more than the ground pins were bend.

Because I can't think of any reason why would someone swap the eprom, I want to know if the rest of the board is a 44F07 one or does it make a difference.

My little research showed me that the main difference between 44F and 39F is the o2 sensor. 44F shouldn't have the neccessary transistor to heat the o2 sensor and it has a IC for the afm screw (IC60, mine is blank on the pcb, I also don't care about the o2 for now). There is a printing on the PCB that says MEC-d001-d010 that suggests me that a 39F00 nistune would work with it being a d007d.

My car starts fine but it gets leaner and leaner as the CTS value rises and struggles to keep idle after some time. Restarting the car resets CTS value back to 20ish, so the afr starts ok with %20 enrichment, and goes bad later again (CTS is not rising properly, more on that later.).

My car used to run lean, but it didn't struggle to keep idle this bad. The major difference between the base 07 map and the 09 map is the warmup timing min value, which is set at 204 at 09d to probably bypass it.

To sum up:

Did any of you tried using a 39F00 nistune with a 44FXX board?
Can anyone give my tips to identify the main board of my ecu?
Can I upload the MEC-009D bin on 39F00 nistune board to see if my car behaves as it used to?


2 CTS Error :

My CTS throws up an error code at the start. When the ignition is turned on, the CTS starts around value 20, and climbs up step by step while the power is on ( doesn't matter if the engine is running, or what the water temperature is actually). When the power is cut, and ignition is back, the CTS value falls back to 20 ish .

I can't figure out how a bad thermistor can behave like that so I wonder if it is a bad CTS, or it is because of the board mismatch. Have you ever seen a CTS behave like that?

Any opinions about this are welcome.

3 About base maps :

I noticed that the base maps in the rom pack (d007d and d009d in particular) don't have knock maps that differ from the primary map. Are the base maps identical to the maps on the stock roms? Aren't they supposed to have altered knock maps?



Thanks and greetings from Turkey /Istanbul

Ozan

1. Have a look at the label on the side of the ECU case. There should be a MEC number which should match the lid of the case

Not sure why 44Fxx was swapped into 39Fxx ECU

It is normal for the temp enrichment to drop off (have a look at the temp enrich tables in Nistune). Are you running stock setup at the moment?

The AFM calibration screw affects the base mixtures. This is only in the 44Fxx ECU code. This may be helping things to run even no AFM calibration is connected in your vehicle

2. I think the above problem is related to your CTS fault. It will automatically increase when not connected. You need to fix your CTS and remove the fault code

3. Not sure on the last one, havent really checked. Usually only minor differences