CM871 Tune

[Rawze]

Here is how the straightening out process for bad programming works for those who are curious, assuming they live in a foreign country where that kind of stuff is legal ...

* Make a full backup of the bad program/tuning using C*term. Insite will not make a proper backup of it. This is only just so that you have what was already in the truck it in case you need an address for a component in the the J1939 specific to your year/make/model or something.

* Make an "ECM image", and an "ECM Template" in Insite to save all the dash and other typical settings like cruise control, max engine speed, rear ratios, speed governor, etc. (this is not an actual backup of the ecm by the way, just the main adjustable features settings for the truck itself).

* Flash it back to the exact factory file that belongs to that engine based on its serial number. DO NOT put a higher HP file in it. Use the EXACT ONE for your engine!. HP and other things can be adjusted later from within your correct file. This is done with Insite and a clean, up-to-date factory file from cummins.

* Restore the "ECM Image/template" back into the ecm to put the dash, cruise, rear ratio, and other truck settings back into the new factory file if necessary.

* Run the engine for at least 10 minutes on the original factory file. Alarms for de-mandated things are ok to have during this. The engine needs to run to rebuild RAM data and restore the injector/cylinder balancing data, etc.


* Make ANOTHER backup/image of the entire ECM using Cterm program of the now clean factory file.

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(the del/custom tuning part) ...

* Use the latest version of 'M - M - 2' overlay on it if available or e-mail to to someone that can be trusted to do it up for ya that can set everything correctly. Adjusting the turbo, injection timing offset, etc. properly for the HP you are going to make it. SEEK some professional advice if you are unsure about what is safe or unsafe if attempting it yourself. Also get a second opinion on what you have set before committing on any changes you or someone else has made.

* To change the power/torque ... Someone needs to properly adjust the dozen or so tables for the desired torque curve and HP for the engine TO MATCH YOUR CORRECT FACTORY PROGRAM instead of some ignorant fool dumping a different HP tune in it designed for a different truck/engine.

- Some people do this for themselves, some people have someone remotely do this or have it done at a shop, etc. ... and some people simply e-mail the file to have this part done so that they don't make mistakes.

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* Put the newly adjusted program back into the engine (using Cterm) and clear out any inactive faults (using Insite) by following the 'reset all faults' procedure, do this 2 timnes in a row, to clear any ghost faults that may have accumulated when you ran it previously.

* Ensure the "cans" (DOC/DPF/SCR) in the exhaust are ALL 100% hollow! and NOT just a bunch of little holes or a single 4" crap wannabe half-arssed job of turbo-killing heat restriction done. I have seen a lot of places half-arsse this part only to see repeated engine and turbo failures down the road.

* Adjust the overhead valves if it is more than 250k miles since last done, replace the IMAP and Exhauyst BP sensors if they are more than a year old and do general tune-up/check/maint. work on the engine to ensure it is running well including injector leak tests and cylinder cut-out tests, etc.

* Install Pyro and boost gauge into the truck to help the driver save fuel AND for testing the boost and other settings to ensure they are correct with the new engine tuning.

* Test the truck under full operating loads to ensure all settings are safe, turbo does not over-boost the engine, internal friction and EGT's are correct, injection timing is within safe limits for the power being made, fuel mileage and other readings are ok compared to other trucks of its same type, there is no excess vibrations, full power is being achieved, etc.

max boost allowed for ...

CM870,CM871 = 38-39 PSI max with higher HP tunes(500+ hp), and 37~ish psi max for mid-tier power ranges (below 500 hp). 39 is the upper extreme limit.

CM2250's = 34-36 PSI max no matter what HP your trying to make. 36 is the upper extreme limit.

CM2350's = 33~ish PSI max for mid-tier power levels and 33-34 psi max for high hp. 34 is the absolute upper extreme limit on this engine.

X15's = 28-30~ish PSI max for mid-tier power levels and 30-32 psi max for high hp. 32 is the absolute upper extreme limit on this engine.


* Test the cruise control, engine brake, and all the other truck settings that were restored into the new engine file.


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Do you really think you are going to get someone to do all of the extra stuff required "Remotely"?. - I would say someone should only ever resort to "remote tuning" only if they are absolutely incapable of getting the truck somewhere to have things done properly by someone trained to do and test everything I stated above professionally.

I would bet that the place you took it to (when you got ripped off by bad programming) did not do 1/3 of what is needed to get one right. it takes much more than a program to ensure an engine is running well when such drastic changes to it and its programming takes place. - There is no "Magic pill" solution with such an expensive, complicated, modern style diesel engine.

Personally, knowing an engine is worth $36,000 to replace, and almost as expensive to rebuild .. I would take it down to Mr. Hags to have every bit of what I mention checked or consulted on instead of only doing the "programming part" if you really want things absolutely right.

Never question what shape your truck is in, your engine is in, or its programming!. - KNOW what you have and understand what it is doing. Know what someone has done to it very well, and if anyone is unsure about the program someone stuck into their ISX, they can send it to me and get a second opinion on it.