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+--- Thread: CM870 power issues (/showthread.php?tid=8573)
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RE: CM870 power issues - Rawze - 12-07-2022
(12-07-2022 )kamiar Wrote: ...
I hear you, we run a lot of engines on this dyno and they all make the exact hp that they are supposed to, only these CM870 CPL 8018, boost is 32PSI full load, fuel flow i am not sure but i will look again and report here, btw the timing and metering actuators are replaced as well...
if you are jumping CPL or are running the wrong program for the engine vs. its injectors and other internal hardware.. it can cause some discrepancies too. There are different injectors with different programming requirements in these engines.. and running the wrong program for the hardware is a no-no that can lead to efficiency problems and other issues like incorrect fuel quantities to go along with this, etc.
Also, for the CM870's in particular.. some CPL's have different wedge settings on the cam.. so those programs specific to this need to match as well.
then there is the matter of "what truck" that program belongs to... just because it has the same CPL does not mean that a particular program is made for a certain model/make of truck. -= I.E.> a program meant for a prostar or cascadia .. even though it has the same exact CPL (engine hardware) .. will NOT BE COMPATIBLE with a W900 truck with its significantly larger CAC, piping, exhaust, etc. -= this is a mistake that i see a lot of people do and then complain that their fuel mileage has gone to s$it.
There are also programs that were written for emergency vehicle applications.. and not meant for a highway truck at all. -= all within the same CPL range as a highway truck. -= These programs are very hard on the engine overall, so installing one of these programs into a highway truck WILL SHORTEN ENGINE LIFE BY QUITE A BIT and eventually tear the engine up because the program is meant to abuse the engine and operate it in a cold state with full power and most of the settings are not meant for a truck that is going to be going down the road all day with it fully warmed up and heavily loaded.
RE: CM870 power issues - kamiar - 12-08-2022
Yes i agree 100% and am well aware of these issues, i have downloaded the calibration from quickserve by the ESN, even tried another good used ecm and programed it with same ecm code, same result.
But to be honest with you, i am not sure about the mechanical side of the things, someone else has put this motor together, so i am not sure if this cam wedge setting or timing etc can cause this higher than normal hp without trowing a code!
RE: CM870 power issues - Rawze - 12-08-2022
(12-08-2022 )kamiar Wrote: Yes i agree 100% and am well aware of these issues, i have downloaded the calibration from quick-serve by the ESN, even tried another good used ecm and programed it with same ecm code, same result.
But to be honest with you, i am not sure about the mechanical side of the things, someone else has put this motor together, so i am not sure if this cam wedge setting or timing etc can cause this higher than normal hp without trowing a code!
like I said.. monitor the mg/stroke at full operating loads and see of the ecm is commanding that much power. If it is not indicating this then there is a mechanical problem where fuel is getting in that is not accounted for and should not be. Maybe wrong injectors, maybe slipped cam?.. I doubt that though.. or maybe wrong solenoids for fueling?.. or some other thing. Also check the fuel pressure sensor to ensure its feedback is correct vs. a pressure gauge.
RE: CM870 power issues - Scooby d - 12-09-2022
(11-21-2022 )Zocaid Wrote: Is this fuel actuators or something else? Truck takes off and pulls sluggish and harder to shift gears after 2 days driving then clears up over the weekend after sitting two days. Almost seems like a boost leak but problem consistently clears up after sitting. It’s a head scratcher.
Just throwing out ideas..... restriction in fuel return line... a air leak on the suction line or tank tube that gets worse as the fuel gets warmer.... plugged tank vents...
RE: CM870 power issues - tree98 - 12-09-2022
(12-09-2022 )Scooby d Wrote:(11-21-2022 )Zocaid Wrote: Is this fuel actuators or something else? Truck takes off and pulls sluggish and harder to shift gears after 2 days driving then clears up over the weekend after sitting two days. Almost seems like a boost leak but problem consistently clears up after sitting. It’s a head scratcher.
Just throwing out ideas..... restriction in fuel return line... a air leak on the suction line or tank tube that gets worse as the fuel gets warmer.... plugged tank vents...