(base) Idle timing settings?

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Torque
 

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(base) Idle timing settings?

Post by Torque »

Where would be the table(s) that dictates base ignition timing for idle (15 degrees) on Z32 ECU?

Is it these two? (the degree values seem to be wrong in the first left table, both they seem to be identical)
WARMUPTIMING.JPG
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Also why are all the Idle Stabilization Tables ZERO??

And how and based on what parameters does the Z32 vary timing to maintain stable idle rpm?

Any input welcomed

IdleTiming.JPG
(153.22 KiB) Downloaded 2773 times
Matt
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Re: (base) Idle timing settings?

Post by Matt »

Nissan ECUs will use timing closed loop control to reach the 'idle target RPM' table desired RPM. These tables are mainly used when outside the closed loop control when TPS is idle (for example on deceleration)

Normally the timing is advanced/retarded using the values in the idle stablisation tables. I am not sure for Z32 ECU why these are values or 0 (normally the min/max is the amount of adjustment, and the minimum and maximum amounts of timing to adjust by)

Right click the table and make 'filtered' to reduce the 128 timing offset in the LHS table
Torque
 

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Re: (base) Idle timing settings?

Post by Torque »

Hi Matt,

I think the Z32 ECU is not running in closed loop when at idle (no idea why ... ). There were many posts about trims etc. and it was always established that the Z32 ECU does not use closed loop (@idle). I myself found that the case to be when logging ..

And yes, on the Z32ECU all those idle stabilization tables are ZERO, so I'm unsure what the principal of operation is to adjust timing @ idle.
Could it be that there are some undiscovered tables?

I also copied all the adjustment tables from my RB25.bin to my current Z32.bin but it didn't seem to make any difference.

Any yes, my bad ... should have switched to filtered view :0 (why does one table come up in raw, while the other one does not ..?)
Torque
 

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Re: (base) Idle timing settings?

Post by Torque »

(FastForward)

I just established that this table:
IDLEZ32.jpg
(38.09 KiB) Downloaded 2745 times

dictates the idle base timing .. the ECU works the timing correction for stable timing from this baseline.

There must be other tables dictating how much the timing can vary.
Matt
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Re: (base) Idle timing settings?

Post by Matt »

I think the Z32 ECU is not running in closed loop when at idle (no idea why ... )
I was referring to closed loop timing adjustment (not O2 sensor closed loop). Closed loop is where adjustments are made based on the feedback of input of a sensor

Closed loop O2 uses O2 sensor for injection adjustment... closed loop timing uses RPM against target idle RPM table for timing adjustment
There were many posts about trims etc. and it was always established that the Z32 ECU does not use closed loop (@idle)
This is correct. I got an email this week from another Z32 owner who referenced the service manual mentioning that closed loop O2 is not done at idle (STFT and LTFT gauges actually showing enrichment values it appears at idle and outside closed loop, not actual trims)
And yes, on the Z32ECU all those idle stabilization tables are ZERO, so I'm unsure what the principal of operation is to adjust timing @ idle. Could it be that there are some undiscovered tables?
Perhaps... or a different way of doing it
Any yes, my bad ... should have switched to filtered view :0 (why does one table come up in raw, while the other one does not ..?)
Not sure. How Nissan coded it. Some tables use a +128 offset for O2 or knock feedback adjustment

Also Warmup Timing is only used between 30 .. 55 deg C (and upto 2600rpm, 44 TP) as per the Warmup Timing Control parameters

Okay so it must use the idle/decel table in conjunction with target idle RPM table to work out final timing based on actual RPM
Torque
 

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Re: (base) Idle timing settings?

Post by Torque »

Thanks Matt,

My bad, I thought by closed loop you were referring to O2 closed loop.

It's a bit strange that at idle there is not closed loop O2 adjustment happening, I thought that was part of an emissions test.
Any idea what dictates the mixture at idle then?

... I will try to investigate what the other idle timing table is used for.
It says Warmup Timing, but I see no temperature index in there.
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Re: (base) Idle timing settings?

Post by Matt »

Warmup timing is documented. Its only used in that temperature range per my last reply (ie during warmup) it locks the timing in the low load/rpm range. Many customers disable the table completely.
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