Cranking fuel tables

Nistune topics related specifically to the 6303 cpu

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Torque
 

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Re: Cranking fuel tables

Post by Torque »

OK!
Adrian
 

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Re: Cranking fuel tables

Post by Adrian »

I had some issues in the last days with a R33 rb25det with Z32 8bit ECU.
I have reseized the injectors to sard 650ccm and the MAF to Z32. So the Crank enrich table values were ~halved. After that the car had much troubles to start. It endet that i have nearli doubled the crank enrich table values above 50 C based from the table bevor the injektor and MAF change! The car starts now perfekt when the coolant temp is hot. What i've seen until yet it starts also well with cold coolant temps, but i will have a look at again, when the wheater is colder. I think to halve the Crank enrich table on the Z32 ECU is the wrong way. Can it be that it is somethimes necessary to change the voltag latecy table, if you have bigger injectors?
Torque
 

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Re: Cranking fuel tables

Post by Torque »

Hi!

Did you adjust the latency for the injectors at all??

Also, did you rescale the TP-Scalers?
To what extend did TP-Max change?

It seems odd that you had to double the crank enrich table (which one? cold or warm?)

The RB25 has 370CC, double would be 740CC, not 650CC.

My car starts fine (cold or hot) by reducing the % based first time enrich table.


Cheers :)
Adrian
 

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Re: Cranking fuel tables

Post by Adrian »

[/color]
Torque wrote:Hi!

Did you adjust the latency for the injectors at all??
Yes i adjust the latecy to 1500us ( latecy what sard says), afr are well wen the car had been started

Also, did you rescale the TP-Scalers?
To what extend did TP-Max change?
I chose all selections when i chaged the maf and incetors on. Yes Tp has changed to tp75 (in last point after resize maf and injector.) at the fuel scale.

It seems odd that you had to double the crank enrich table (which one? cold or warm?)
I changed only the crank enrich table, not warm or cold enrich and also not the after start enrich table. I'm not sure if we mean the same table. I the list on the left side, it'called crank enrich. Maybe the table called first time enrich when you open it. (i have my laptop no here yet, to check it.

The RB25 has 370CC, double would be 740CC, not 650CC.
Thats the reason why i writhed nearlydoubled the values.

My car starts fine (cold or hot) by reducing the % based first time enrich table.


Cheers :)
exxon
 

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Re: Cranking fuel tables

Post by exxon »

i have the same question. After switching from 270cc to 440cc and z32 maf on my rb20, i figured multiplying the mS values of the "first time enrich" table by .61 i would be close. Car is hard as hell to start cold. Need to be on the throttle and it takes a few cranks. ECU is getting start signal. Cold/Warm enrich tables are unmodified
Torque
 

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Joined: Wed Jun 16, 2010 10:08 am

Re: Cranking fuel tables

Post by Torque »

Hi there,

I have the same issue when the car is warm, when the engine is cold it starts ok.

That's either due to a 'warm' table being used while cranking and/or some mixture being too rich(?)
Or maybe the ECU uses different tables to start when the throttle is open??



Your multiplier should be .63 (62.9% increase 270->440)





exxon wrote:i have the same question. After switching from 270cc to 440cc and z32 maf on my rb20, i figured multiplying the mS values of the "first time enrich" table by .61 i would be close. Car is hard as hell to start cold. Need to be on the throttle and it takes a few cranks. ECU is getting start signal. Cold/Warm enrich tables are unmodified
exxon
 

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Joined: Mon Dec 19, 2011 1:34 pm

Re: Cranking fuel tables

Post by exxon »

I noticed in the latest beta version of nistune "0.10.19", the Crank Enrich value changed from "mS" to "%". Although using the "resize injectors" function stilll resizes the "Crank Enrich" table. My values went from 25,18,9,5,5,5,5,4,4, to 15,11,5,3,3,3,3,2,2 0-80deg C. Cold start seems worse than the stock rb20 enrich values. Odd since my injectors have increased size so much, i figured it would improve.

As i said the warm/cold enrich has been left factory. K constant is more or less the same as factory being that i switched to 440 and z32 maf. (+4) Figured tables shouldn't have to be modified for such a small change, with crank enrich being the only exception being that is in "mS". But now that Matt has switched values to "%" i'm not so sure? Resize injectors seems to think so.

Thanks
Torque
 

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Re: Cranking fuel tables

Post by Torque »

Hmm ... that is strange ... I mean that the unit is now % and not mS anymore!
I thought it was the whole point of that table that the ECU is not working in %, but in fixed time slices.

On what ECU are you?
(Me Z32/Type 2)

Here's how my table looks like:
ENRICH.jpg
(33.13 KiB) Downloaded 4031 times
Maybe I have to reduce the values up from 50C further ..

Funny that your car has issues with cold start as well.
exxon
 

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Re: Cranking fuel tables

Post by exxon »

I'm using an R32 RB20DET ecu/Type 2
I always understood the crank tables to be in time as well. But now i'm not so sure anymore. Hopefully someone can chime in. Here's my modified vs stock table
Attachments
crankenrich.jpg
(78.9 KiB) Downloaded 4028 times
Matt
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Re: Cranking fuel tables

Post by Matt »

0.10.19 version is the change to crank enrich (second image)
Torque
 

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Re: Cranking fuel tables

Post by Torque »

Thanks Matt .. Crank Enrich makes more sense I suppose.

But is the scaling actually time or %???

:)
exxon
 

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Re: Cranking fuel tables

Post by exxon »

Torque wrote:Thanks Matt .. Crank Enrich makes more sense I suppose.

But is the scaling actually time or %???

:)
Any answer for this?
Matt
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Re: Cranking fuel tables

Post by Matt »

Should be ms for cranking table since its just a raw value read and used for injection time. I need to check it out further to see why RB FT_INJECT tables are ms and SR20 ones were %

I think they all should be ms but need to double check why the SR20 definitions from the XDF files were %
exxon
 

Posts: 28
Joined: Mon Dec 19, 2011 1:34 pm

Re: Cranking fuel tables

Post by exxon »

Matt wrote:Should be ms for cranking table since its just a raw value read and used for injection time. I need to check it out further to see why RB FT_INJECT tables are ms and SR20 ones were %

I think they all should be ms but need to double check why the SR20 definitions from the XDF files were %
Mine is rb20 and changed from ms to % in the latest beta.
Matt
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Re: Cranking fuel tables

Post by Matt »

RB should still be ms. Just need to check SR20. Wont be this week, got other things to finish first. On my list to look at
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