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dodges15152023

ISC CM2250 Idle Surge, no active codes, zero accelerator/ throttle response.I have an issue with my 2012 Feedtruck Off-road only in feedlot in North Dakota, ISC CM2250 Idle Surge, no active codes, zero accelerator/ throttle response only inactive code is a 2288 turbo overspeed,. Truck started as usual in temperature controlled building, it was idle up to build air, backed out then went to surging at idle and no response from throttle, pushed it back inside.
Turbo speed is defaulted to 150,000 RPM and cannot get it to change. Also Turbocharger Actuator position commanded and measured are locked at 4 percent and I cannot change .
I have troubleshot with quick serve, the speed sensor ohmed correctly and I also substituted another sensor in its place, I also disconnected the harness from actuator and turbo speed sensor and ECM, I checked Pins at ECM harness to Pins at sensor and actuator harness pins for resistance, pin to pin shorts and opens and harness check to specifications.
Turbo and actuator have 1 season on them so roughly 1200 hours, truck is aggressively maintained at all times.
Truck does have 25,000 hours on engine and drivetrain all under 35 mph in yard.
Truck was “fixed” by Ryan mechanical 8 ish years ago and has performed flawless with aggressive maintenance.
Tomorrow I plan on trying to calibrate a different actuator and see results.
Fuel pressure is within specifications.
It will start instantly but surge from 900 ish to 499 ish RPMS but never dies.
Any thoughts or suggestion are greatly appreciated.
I do have the twin to this truck for compare to.

Btech

Good chance there are some blocked faults that pertain to this issue that you cant see. Turbo parameters going to default values should have some type of fault code to accompany that.
Just from what you describe though makes me wonder if there isn't a engine datalink wiring issue somewhere causing all your issues. I would check and go over that first.

Rawze

== turbo over-speed codes are not good.

== Does not matter who 'tuned' it ... If it was programmed 8+ years ago.. that is an eternity i n the computing world. The program at this point needs to be updated badly, as well as checked at this ensure it is not harmful to the engine. Copy the program from the ecm and e-mail it to me for a proper review of what someone did in there.. and as well to ensure there are no fault codes being blocked that can reveal your current issues.

surging like that at idle is either turbo, air-flow, or fuel pressure issues ... or a combination of them.

So .. will it pass a fuel rail leak test?. What is the leak rate?.
ref: http://rawze.com/forums/showthread.php?t...3#pid75483

also... you need to check the commanded vs. measured turbo positions in the ecm to see if they match. If they do not, then there is problems with the actuator being able to position itself correctly.

dodges15152023

(03-27-2024 )Rawze Wrote: == turbo over-speed codes are not good.

== Does not matter who 'tuned' it ... If it was programmed 8+ years ago.. that is an eternity i n the computing world. The program at this point needs to be updated badly, as well as checked at this ensure it is not harmful to the engine. Copy the program from the ecm and e-mail it to me for a proper review of what someone did in there.. and as well to ensure there are no fault codes being blocked that can reveal your current issues.

surging like that at idle is either turbo or fuel pressure issues ... or a combination of them.

So .. will it pass a fuel rail leak test?. What is the leak rate?.
ref: http://rawze.com/forums/showthread.php?t...3#pid75483

also... you need to check the commanded vs. measured turbo positions in the ecm to see if they match. If they do not, then there is problems with the actuator being able to position itself correctly.

Commanded and measured do match, always at 4 never different. If you watch closely when you cycle key on off they do "flash to a change" but is very fast and undiscernible at best.
I performed a "install Calibration on a second back-up used actuator and it passed if you will correctly with no issues.
Yesterday morning it would not start, and was short on fuel pressure.(under 8000 cranking).
I will get more Data today hopefully, we are in the middle of Calving season and below zero night temps NO SLEEP but will get back on task. Thank You.

dodges15152023

Fuel pressure command in my opinion is not enough in my opinion,maximum commanded is 11306 and measured is 13686 when running/surging, truck has been off for over an hour,pressure when key was cycled off to on after running was 8473 commanded and 8909 measured and current pressure is holding at 8867. I put a new Cummins high pressure fuel pump assembly to try new angles and have connected a davco fuel processor to support supply circuit. This truck typically idles at 12,250 psi to 13,780 psi according to my records and logs.
Turbocharger Speed still at 150000 default and 4 commanded and 4 measured.
This truck has 25000 hrs but is aggressively maintained. And performed flawless the morning before.

Additionally and worth noting maybe is Fuel Pump Actuator Duty cycle is never over 50 percent at anytime, shows fluctuations from 30's to 50.

Rawze

When I mentioned 'fuel pressure issues' as a possible cause, here is more on that. Your descriptions actually point away from this as being an issue...

Typical fuel pressures at idle for an ISC on a de-mandated engine should be in the 490 - 530~ish bar range. On a healthy engine, they do not start to show signs of surging until its down in the 460bar or so range .. 420 being the lowest pressure it can be programmed to before it becomes a real problem. If it is set low, then how low it can go before it starts surging is highly dependent on the restrictions in the CAC/intake, and this is per vehicle .. so 520-bar is high enough and safe for everything that I have ever seen, even on poorly designed intake systems like the (garbage from the factory) highly restrictive CAC units that F750's have in them, as well as most RV's with their highly restrictive garbage CAC's on them as well. After-market CAC units make this even worse most of the time too.

This means that if your seeing 580~ish bar (8470 psi) at idle, .. then the fuel rail pressure alone is not likely be your problem at all. Your mention of it running 580-bar at idle actually sounds slightly high, not low ... and higher than normal fuel pressures at idle will NOT contribute towards surging, but the opposite .. and mostly result in causing a noisier valve-train, especially when the engine is cold instead.

as well. that turbo, and its speed sensor feedback needs to be fixed properly too. For all anyone knows, that highly likely could be the bulk reason that it is not running right. It should not be showing 150k rpm's at idle. - Has anyone even bothered to take the actuator off it and ensure it is not locking up at 100% closed.. choking the exhaust manifold off and causing all the surging, etc.. because the exhaust manifold itself cannot breathe properly?, and the controller just does not know it?.

you guessing it into oblivion is also not going to solve your issues. You need to see what that engine and its ecm is doing via calterm,.. and what is in control of that fuel state in particular while its acting up. - that will point you towards why it refuses to idle up, and will also likely point towards other issues. for all anyone knows, the engine might have jumped operating modes and is not stuck there due to one reason or another, so things need to be checked properly.

Use this CT screen file to see what is gong on. Get some desktop recording software and run the engine .. record the desktop and the data in the screen live... while its acting up, etc.. and then others can analyze the data for the fuel states, engine operating modes, etc.etc. and other things properly.
ref: http://rawze.com/forums/showthread.php?t...6#pid28636

dodges15152023

(03-28-2024 )Rawze Wrote: ... if your seeing 580~ish bar (8470 psi) at idle, .. then the fuel rail pressure alone is not likely be your problem
..
Use this CT screen file to see what is gong on.
...
ref: http://rawze.com/forums/showthread.php?t...6#pid28636

Interesting Information. I will look into getting CT on a machine and OBS perhaps to capture. I did check the "sister truck" to this truck (sequential SN numbered) and it idles at 13,500 psi, will video this also and post at later date, Tuesday I will go South at the Buffalo Feedlot and will check the third truck and get more Data to post.

Rawze

and did you do a proper fuel rail leak test?. What is the leak rate in 60-seconds?.
ref: http://rawze.com/forums/showthread.php?t...3#pid75483

dodges15152023

(03-30-2024 )Rawze Wrote: and did you do a proper fuel rail leak test?. What is the leak rate in 60-seconds?.
ref: http://rawze.com/forums/showthread.php?t...3#pid75483

Truck is not stable enough to run this test as per CI.