Cranking tables doesn’t work

Nistune topics specific to the 6802 cpu

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Xaser
 

Posts: 6
Joined: Wed Feb 21, 2018 4:15 pm

Cranking tables doesn’t work

Post by Xaser »

Hi, I have this problem

Engine : CA18DET with 820 injectors, z32 maf.

Nistune : oem table , with resize injector and scaled maf and set the rev limit to 6000 rpm (brand new engine)

First runs work fine but then when car turn off don’t turn on, (cold or hot is the same).
Remove the inyector clips, turn on and idle a few seconds.
ok I think maybe the injectors leak... come to my home, turn off , the same process (take the clips, turn on) and let on contact for 35 minutes, go and turn on fine.
Results injector didn’t leak at all.

Check enrich after start and cranking , at 30c says 1ms
I use the trace to check, and hit 24ms.
I put 0 on cranking and enrich, so do it again....reset trace and.. pum says 24ms again
Ok the trace is “broken” I think , I read the gauges
When turn on the key go to 300ms (yes, three hundred)

So the car doesn’t turn on, because the injector time/pulse at star is soo large, and I cannot see the way to let it down

I have some pictures and videos from trace and gauges if anyone want to see or my descripción is weak
Matt
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Re: Cranking tables doesn’t work

Post by Matt »

Crank enrichment is one of those values which the ECU calculated only when the START signal is seen by the ECU. The ECU will only use the CRANK ENRICH and CRANK TIMING tables

So firstly make sure the ECU is showing START signal in the Consult View panel when you attempt cranking

Next the consult may not report the 'ms' during CRANK time so the value you see in the TRACE window may not be correct

The injection time in the table is what the ECU uses (if you measure the injector signal with a scope) and 1ms at 30degC is too low.

It seems you may have ticked the 'crank enrich' table during injector resize and the values in this table are too low

Factory values from -40 to 115
62 62 59 56 55 46 42 39 36 31 23 16 12 9 7 5 4 4 3 3 3 3 3 3 3 3 3 3 3 3 3 3

So around 30degC the factory value is 7 deg BDTC

Start again with factory values and adjust by hand throughout the temp range until it starts at each temp (20, 30, 40 ... 80 degC)

Auto calculations are fine for smaller injectors, but larger ones (740CC +) should be done manually
Xaser
 

Posts: 6
Joined: Wed Feb 21, 2018 4:15 pm

Re: Cranking tables doesn’t work

Post by Xaser »

Matt wrote:Crank enrichment is one of those values which the ECU calculated only when the START signal is seen by the ECU. The ECU will only use the CRANK ENRICH and CRANK TIMING tables

So firstly make sure the ECU is showing START signal in the Consult View panel when you attempt cranking
Yeap, the Start Signal is ok.
Matt wrote: Next the consult may not report the 'ms' during CRANK time so the value you see in the TRACE window may not be correct
Mmm ok but is the value matchs with the reality, the engine is flood on start.
Matt wrote: The injection time in the table is what the ECU uses (if you measure the injector signal with a scope) and 1ms at 30degC is too low.

It seems you may have ticked the 'crank enrich' table during injector resize and the values in this table are too low

Factory values from -40 to 115
62 62 59 56 55 46 42 39 36 31 23 16 12 9 7 5 4 4 3 3 3 3 3 3 3 3 3 3 3 3 3 3

So around 30degC the factory value is 7 deg BDTC
1ms at xxxxdegC also flooded the engine.
Matt wrote: Start again with factory values and adjust by hand throughout the temp range until it starts at each temp (20, 30, 40 ... 80 degC)

Auto calculations are fine for smaller injectors, but larger ones (740CC +) should be done manually
I let the car all the night, go in the morning, upload the factory map , resize inyector and maf ( Without check the cranking box).
The engine turn on, a little bit rich, but let until 84 DegC, turn off, try to turn on, and flooded the engine again.
Remove the injectors, put on ultrasound cleanner, and check, works fine, no leaks at all.

Turn on, works fine, turn off, turn on... dont run again flooded.


Also, when the engine is running i took the fuel map, and down the 50% of fuel ( on the idle range, 500-2000) Upload, and the engine no change at all, i dont know if this works for any conclusion too.
Matt
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Re: Cranking tables doesn’t work

Post by Matt »

Okay so multiple problems here, may not been ECU related

When car is running watch your "injection time" and then adjust K/TIM parameter to adjust total fueling. Make sure this is changing as you adjust injection time

If it is then changes are working, next with the fuel map, make adjustments and also watch injection time. Does this change at all? Do you have knock fuel map at all? Maybe its accessing knock fuel map

I'm not sure why your cranking is rich. When did this start happening?
Xaser
 

Posts: 6
Joined: Wed Feb 21, 2018 4:15 pm

Re: Cranking tables doesn’t work

Post by Xaser »

Short Story : Works!!!

Long story, upload the oem map, Only scale MAP.

Turn On and nothing.... Put Cranking in 2ms , soo rich, but start..

Use the Inyector multiplier, Oem was 100%, put 48% and the car Star , run smooth, idle by herself.

So , for this, is solved.

Now is time to continue tunning, tomorrow gona highway to test and measure.

I forgot :
The fault start when i was mapping, the engine is fresh assembly, and the first time at more than 70° don´t start.

Matt, thanks for the guide!
Matt
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Re: Cranking tables doesn’t work

Post by Matt »

Good you got it sorted. You can use the 'compare' button to see changes between saved tunes if you wanted to go back and investigate what might have changed unexpectedly
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