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ISC 8.3 issue
#4
(02-18-2020, 12:58 PM)zyNoT Wrote:
(02-18-2020, 11:35 AM)DewDewMax Wrote:
(02-18-2020, 02:15 AM)MaraJin Wrote: In your operation mode references ...
Chi_table_mask 00000001 <= Alpha0 engine mode is being selected.
 Chi_mode_status 0040 <= This is confirmation that Alpha0 is being applied.



in your PTO mode references ...
Chi_table_mask 00000010 <= whatever it is says in 'CBR_base_chi_high', 'CBR_base_chi_low' modes are being selected.
Chi_mode_status 0020 <= This is confirmation that Chi4(protection) is being applied.



just some bit if fyi related to your post:

Just because you edit the cbr vector settings to ask CBR (Combustion Base Reference Manager) to stay in a certian operation mode (chi4), does not mean that down-stream in the selection process, the ecm will follow it. The entire CBR is located at an early stage in the pipeline of final selections. - I.E.> There are things downstream that can still change the final selection, it depending on what was (or was not) done.

- If it is running not so well in chi4, then you have something set wrong somewhere, or perhaps there is something wrong with the engine itself. Also, since Alpha0 is being requested and applied when you do not expect (or perhaps do not want it to be), either you missed something, as it is actually NOT in chi4 during run operations, or it is in an engine warmup state (engine is not at operating temp yet) and Alpha0 selection logic is acting its factory normal.

You did not mention if the engine was fully warmed up or not. Also maybe verify if the engine temp(s) readings are correct in the ecm. Also it might be in what I call the 'run-home-to-momma' state for one reason or other, as mentioned further below.

--OR---
Was the engine block temps actually quite cold? (below 60 degrees-F) - If so, then what your seeing may actually be normal, as Alpha0 should be the one active at this point, and going into PTO right away and it cold, maybe you set it to go chi4, if it has been overriden, and the result will be injection timing made for a fully warmed up engine, and not something that is still quite cold .. leading it to run like crap till it warms up.


for those not familiar:

Alpha0 = Engine warmup mode (not fully at operating temp). A lot of extra timing advance is applied so the engine can run when its not warmed up yet.

chi4 = The built-in, non-egr factory run mode, but also it applies engine protections unless someone edits the mode itself to remove these extra protections.

also, many ecm's (cummins) will use the Alpha0 engine operating mode as a sort of 'run home to momma' mode if it gets confused enough, or if it thinks the engine cannot handle the cylinder pressures, regardless of all other selections or requests in the CBR and other systems. In the case of the excess cylinder pressures (someone turning the power way up improperly, dumping too much fuel in, etc), this can get bad real quick, because when it kicks in unexpectedly, and your making a lot of power, it advances the crap out of injection timing when it does this, usually causing some harm after a while.
i will collect more data and try and get to the bottom of it, final timing remains the same when it switches and runs rough vs runs well. Engine was between 130-175C, however seems to be affect a lot more when ambient temps are very cold, was -20C .I will update shortly, thanks
Sounds like you need to take a look at your cold ambient settings and the selectors for each injection cycle.
Issue resolved, egr was still on truck and opening while cold! why only when it was cold i could not say but it was not mechanically blocked off. Quick plate in the crossover issue was solved! Thanks guys
  


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ISC 8.3 issue - by DewDewMax - 02-17-2020, 03:27 PM

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