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+--- Thread: CM871 surging/shaking at idle (/showthread.php?tid=9565)
CM871 surging/shaking at idle - Mk5Spnd10 - 05-04-2024
Hello.
I’ve got an ‘07 W900 that I installed a CM871 in. I didn’t know much about Cummins engines when I bought the donor motor and thought an ISX was an ISX… Anyhow after making the wiring, hardware and ECM reprogramming I’ve got it running. It’s got an overlay that claims to be the mm ECM deregulation. The problem I have is this thing sounds horrible and shakes the whole truck at times when unloaded or parked throughout the entire RPM band. I did have some errors with the data being copied into the turbo maps they didn't go thru, so I presume my problem is low end boost related as I can’t hear the turbo spool at all until under load. Fuel system tests indicate everything is good, valves adjusted, and it pulls 100,000# without any problems. Boost pressure is around 38 when pulling. Any suggestions on where to start looking for the rhythmic shaking? The errors in Calterm came when copying maps from CBR_SOI_ALPHA1_TABLE to CBR_SOI_Chi4_TABLE. It said the parameters were exceed or something along those lines. Thanks in advance!
RE: CM871 surging/shaking at idle - Rawze - 05-04-2024
copy program from ecm and email it to me for inspection/review.
RE: CM871 surging/shaking at idle - Mk5Spnd10 - 05-05-2024
(05-04-2024 )Rawze Wrote: copy program from ecm and email it to me for inspection/review.
Hi Rawze, I'm trying to attach the xcal file here but it says that type of file isn't allowed. Do i need to change the file type or is there another email address i can send to?
Thanks!
RE: CM871 surging/shaking at idle - Rawze - 05-05-2024
(05-05-2024 )Mk5Spnd10 Wrote:(05-04-2024 )Rawze Wrote: copy program from ecm and email it to me for inspection/review.
Hi Rawze, I'm trying to attach the xcal file here but it says that type of file isn't allowed. Do i need to change the file type or is there another email address i can send to?
Thanks!
email it to me for inspection. I PM'd you my e-mail address.
RE: CM871 surging/shaking at idle - Rawze - 05-06-2024
I was e-mailed this persons program today.
All I can say is ... Welcome to the bad delete club!.
At a glance ...
It looks like someone at least tried to get the enigne running in its built-in factory NO-EGR operating mode. They used an out of date method that has been since found to be unreliable, but its better then nothing. I was starting to have at least some hope for it not being too bad ...
... BUT...
When I glanced at the injection timing .. it has been BUTCHERED INTO UTTER OBLIVION BEYOND ANYTHING THAT ENGINE CAN HANDLE!!!... and is absolutely beyond harmful/destructive. It is as high as 12+ BTDC at high fueling rates in the no-egr mode, and as high as 20+ BTDC in some of the other areas of the programming. This is utterly ridiculous!... not even a 2-stroke from 1950's could run that kind of trash timing, nonetheless a modern 4-stroke.. and the ISX CM871 in particular cannot handle more than about 4-6 BTDC at BEST, at higher fueling rates without it causing harm to it!. -== WOOOOW THAT Is BAD!!!>
NO wonder it runs like total crap!. Its a wonder it has not blown a head gasket or thrown a piston thru the block yet!. At the very least, if this thing has any kind of run time on this bad programming,.. Someone needs to pull the rod/main bearings out of it and check to ensure they have not gotten beat the h#ell up by now!.
NEXT: The turbo has not been set properly for a W900 truck at all!. It has settings that would almost make it over-boost on a Prostar or cascadia.. making it WAAY OUT OF RANGE for a big-nose truck like a W9 or 389Pete. - This on its own is also VERY VERY harmful to both the turbo AND the engine!.
And the power torque curve?...
The power/torque curve has been completely destroyed and flattened out .. especially damaging on the bottom end. The thing is set to try to make more that 1800+ ft.lbs -- ALL THE WAY DOWN TO IDLE, AND TO 0 RPM!S! -- which will absolutely cause engine damage!. CLEARLY,.. CLEARLY someone did not know what the heck they were doing there!!!.
Also, the overall power is set to only 413HP peak across the entire rpm range ... yes,.. someone turned it down.. WAAY DOWN!. Was this by some sadistic request???... or again.. is this someone being absolutely beyond clueless???!.
-- All I can say is .. WHAT A COMPLETE MESS!. Was someone that absolutely clueless?>... or were they intentionally trying to destroy this thing?. - That is the real question. .. because HOLY CRAP ITS BAD!!!. I think this is the worst de-mandate program I have reviewed this year yet!.
No disrespect .. but .. Whoever made this program NEEDS TOME SERIOUS AMOUNT OF EDUCATION!!, and does not need to be touching ANYONE'S ENGINES OTHERWISE!!!.
AND THE TRUCK OWNER SHOULD NOT EVEN BE DRIVING THAT THING AT ALL!!!! WITH IT SET THAT BADLY!@!!!.
Did you try to make this program yourself?... if so,.. the you need to STOP AND SIMPLY STOP what you are doing.
Also.. you mentioned copying tables form one engine mode to another (a1 to chi4) .. YOU WILL NOT FIND ANY TABLE WITH THE CORRECT INJECTION TIMING FOR THAT ENGINE ONCE THE EGR gas flow IS REMOVED!!!> .. AND DOING SOMETHING LIKE COPYING a1 into chi4 will absolutely KILL the valve train and head in about 2 years or so DUE TO ACCELERATED VALVE-SEAT WEAR!!!. I have seen this time and time again whenever people do that. m,any people seem to somehow think that there is some magic tables or unicorns that will fix things inside the ecm and make it all better ... however this is incorrect. THAT ECM IS BEYOND DUMB AS A BRICK!.
and using an overlay .. likely writing settings on top of another bad de-mandate to begin with? .. because if u you had used an official one (like the official mm2w for the CM871 on a stock file), then the things that I mentioned would NOT be in there at all, nor would have such bad numbers.
If whoever programmed this thing wants to learn HOW TO DO THESE THINGS CORRECTLY AND WHY .. Then they need to get on my mumble voice-chat server and learn things properly.. so that they don't destroy equipment!.
my mumble server: http://rawze.com/forums/showthread.php?tid=53&pid=2163#pid2163