[N14] SR20DE+T stalls when coolant <70ºC (158ºF)

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WalknBullzEye
 

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[N14] SR20DE+T stalls when coolant <70ºC (158ºF)

Post by WalknBullzEye »

I'm new to this forum, thereby this is also a way to say hi to you all!

My car is a Nissan Pulsar and powered by a SR20DE highport engine + GT2871R. The engine is totally new and rebuilt with forged parts.
The tables in NIStune are tuned by FC-Tuning.

Unfortunately the engine stalls when cold. After a whole year of trying and searching I did not solve this problem, yet. That's why I ask your help.
On the other side, when the engine is warmed up, it does not stall and drives smooth!

The prolem more explained:
The engine stalls when, for example, the clutch is engaged or when it's put in neutral. The RPM just drops to zero.
This only happens while the coolant temperature is 69ºC (157ºF) or lower.

Wat I have tried:
1. Replaced the IACV/AAC - Idle Air Control Valve/Auxiliary Air Control (new, OEM)
2. Turned out/adjusted the idle screw so much, the IACV/AAC valve is closed for almost 90% in NIStune. If I turn out the screw any more, it will increase idle RPM. Because of this setting the engine will always have quick air, when needed. The last 10% is used to remain steady idle
3. Replaced the Z32 MAF sensor (new, Bosch)
4. Regrounded the MAF sensor
5. Replaced the O2 sensor (new, OEM)
6. Replaced the AICV - Auxiliary Idle Control Valve (new, OEM). The valve which increases idle RPM, when cold
7. Cleaned and tested all four new Nismo 740cc injectors
8. Replaced wires and plugs for injectors
9. Adjusted and tested the throttle position sensor
10. Because I first didn't used a BOV, I installed an internal Forge BOV.
11. Checked all intake gaskets
12. Checked all vacuüm lines
13. Checked the whole intake piping and intercooler
14. Checked the brake booster and its lines
15. Replaced the check-valve, in the line to the brake booster (new, OEM)

Until now the problem is still there. That's why I started to adjust settings in NIStune.
For example the "Enrich (Cold crank)". Tried several settings, more or less fuel. This had no effect.

Then I found the table: "Fuel recover". I looked into these and I know for sure, my ECU doesn't use these settings, for some reason.
I almost thought it was an ECU problem. So...

Image

16. Soldered a socket into a second ECU 23710-71Y05. No effect
17. Tried a third ECU, soldered it again. No effect
18. Contacted FC-Tuning. I sent them my NIStune board and they loaded a new and fresh base image. Ofcourse with the correct base image 23710-71Y05. No effect

19. At last I tried an ECU from a Nissan Primera. It has partnumber 23710-70J00 and I found a second NIStune board with the same base image. I loaded an original file from the ROM-pack and copied all my data/maps into this 23710-70J00 file. Uploaded and burned the ROM to this Primera ECU and tested it in my car.

Problem solved!

Now I can see and notice the ECU really uses the "Fuel recover" table!
Remember this is with a Primera ECU and a second NIStune board (which isn't mine) with the Primera/70J00 base image.

But... because the Primera 70J00 ECU does not have an O2 sensor, I can't get mine one to work! The table "Change flags" shows "O2 sensor analysis" enabled.

You can see the difference between 70J00 (Primera) and 71Y05 (Pulsar):

Image

My questions:
1. It it worth to try (buy) a new NIStune board for my original ECU/71Y05? Maybe my NIStune board is not 100% okay?
2. Can I enable the O2 sensor, on the Primera ECU/70J00?
Matt
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Re: [N14] SR20DE+T stalls when coolant <70ºC (158ºF)

Post by Matt »

If you dont mind not having closed loop then you should be fine to use it as it is. You cannot enable O2 in that current ECU
WalknBullzEye
 

Posts: 29
Joined: Mon Oct 27, 2014 1:18 am
Location: Netherlands

Re: [N14] SR20DE+T stalls when coolant <70ºC (158ºF)

Post by WalknBullzEye »

I really want to use the closed loop option, because I drive a lot of km's with this car.

Do you know more options which I can try, before I buy a new NIStune board?

For example, if I post a log file here, is that useful?
Matt
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Re: [N14] SR20DE+T stalls when coolant <70ºC (158ºF)

Post by Matt »

Not really. If the ECU does not support O2 then you will need to get the board reflashed using a base image programmer
WalknBullzEye
 

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Re: [N14] SR20DE+T stalls when coolant <70ºC (158ºF)

Post by WalknBullzEye »

Ok and a logfile from my original 71Y05 ECU (which supports O2), when it stalls?
Matt
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Re: [N14] SR20DE+T stalls when coolant <70ºC (158ºF)

Post by Matt »

Yes you can post that (record in stream mode). Does that ECU have Nistune fitted through?
WalknBullzEye
 

Posts: 29
Joined: Mon Oct 27, 2014 1:18 am
Location: Netherlands

Re: [N14] SR20DE+T stalls when coolant <70ºC (158ºF)

Post by WalknBullzEye »

Thanks for your answers Matt! My 71Y05 ECU has NIStune yes.

Today I drove again and made a logfile. I hope you can see the engine stalled almost a few times. On the end it definitely stalled.
When it does that, it's because the fuel recover does not work.

The air/fuel ratio gauge is my prove. When the RPM drops, the A/F gauge shows 21:1 (lean). From a certain point it must continue fuelling, but it doesn't. That's why it stalls.

Logfile: http://www.filedropper.com/nistune-1206-1123

I hope maybe you can find a solution in the logfile.
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